Debunking anti-vaccine arguments: VAERS, package inserts, and the VICP do not prove that vaccines are dangerous

 One of the many anti-vaccine double-standards. Image via Refutations to Anti-Vaccine Memes.

If you spend any time talking to those who oppose vaccines, you will likely hear them cite the Vaccine Adverse Event Reporting System (VAERS), vaccine package inserts, and the national Vaccine Injury Compensation Program (VICP) as evidence that vaccines are dangerous. These three arguments are extremely prevalent among anti-vaccers, and many well-intentioned parents are duped by them. In many ways, this is entirely understandable. I think that most parents who refuse to vaccinate are truly trying to do what is best for their children, and I understand why parents are concerned when they see a long list of symptoms that have been reported after a vaccine. However, if you really want to do what is best for your child, then it is important to fact check, use good sources, and use those sources in the way that they are intended to be used. It is on that last point that these three arguments fail. Indeed, none of these three sources are intended to provide evidence of causation, and anyone who cites them as evidence that vaccines are dangerous is misusing them. As I will explain, the fact that an adverse event was reported in one of these three sources does not actually indicate that vaccines caused that event; therefore, you cannot present these sources as evidence that vaccines are dangerous.

Before I talk about these three topics specifically, I want to make some very general comments about anecdotes, because that is what all three of these sources report. As I explained in detail here, anecdotes do not provide evidence of causation. Coincidences do happen, and the fact that two things occurred together does not mean that one caused the other. In fact, it is a logical fallacy to say “X happened before Y, therefore X caused Y” (in technical terms, this is a post hoc ergo propter hoc fallacy). This is especially true with very common events such as vaccines. So many children receive vaccines that, statistically, we expect there to be lots of cases where some form of injury/debility closely follows vaccination just by chance. This is a crucially important point: the fact that an adverse event followed the administration of a vaccine does not mean that the vaccine caused it. This is often difficult for people to accept because our brains are wired to see patterns, but the reality is that we often see patterns that aren’t really there.

Look, for example, at “lucky” items. Does Bob’s “lucky shirt” really help his favorite sports team win? No, obviously it doesn’t. It’s just a coincidence that the team won several games while he was wearing the shirt. Nevertheless, our brains are wired to see associations even when there aren’t actually causal relationships. Further, we are prone to confirmation biases. For example, every time that Bob’s team wins while he is wearing the shirt, his confidence in the lucky nature of his shirt will grow; whereas if the team loses while wearing the shirt, his brain will tend to downplay that or invent an excuse for why the shirt didn’t work for that particular game.

The exact same thing happens with medicines like vaccines. We are pattern recognition machines. So when we see SIDS, autism, etc. follow a vaccination, our brains latch onto that association, when the reality is that those two events might be total coincidences (just as Bob wearing his shirt and the team winning are coincidences). Further, confirmation biases can really skew things. If, for example, you suspect that a vaccine might be dangerous, it is extremely easy to find lots of cases of parents reporting an adverse event after a vaccination, and that will inevitably bolster your belief, but, because of the way that confirmation biases work, you will tend to ignore all of the times that the given event occurred without a vaccination or didn’t occur following a vaccination. As you will see, this is one of the big problems with VAERS, package inserts, and the VICP. They make it very easy to bolster an existing suspicion, but they are actually only showing you part of the story. They give your brain enough information to form a pattern, but not enough information to form an accurate pattern.

Vaccine Adverse Event Reporting System VAERS
Let’s begin with the VAERS database. This is a self-reported database of adverse events that followed vaccination. There are several very important things to note there. First, the fact that it is self-reported means that the quality of data is highly variable and often low. Anyone, regardless of medical training, background knowledge, biases, etc. can report an adverse event. So there is very little in the way of quality control on the reported information. To quote the VAERS website, “Reports vary in quality and completeness. They often lack details and sometimes can have information that contains errors.”

Self-reported databases like this are problematic for a number of reasons, not the least of which is recall bias. Our memories are imperfect and easily biased, and we tend to fixate on some events more than others. Imagine, for example, that a child becomes very ill. His/her parents will naturally want to know the cause, and events like vaccinations tend to stand out in our memories. In other words, we naturally focus on them more than on other seemingly less significant events which may actually have been very important. Thus, parents may attribute the illness to a vaccination that happened a month ago simply because they are looking for answers, and that stands out in their memories.

In addition to the problems associated with self-reporting, it is extremely important to realize that VAERS is simply a collection of events that happened after a vaccination. It is not a collection of events that were caused by a vaccination. Again, remember that the fact that event X happened before event Y does not mean that event X caused event Y. So you can’t actually use VAERS as evidence of causation. You don’t, of course, have to take my word for this, because VAERS explicitly says this. If you go to the VAERS data page, the very first sentence says the following (my emphasis):

“When evaluating data from VAERS, it is important to note that for any reported event, no cause-and-effect relationship has been established. Reports of all possible associations between vaccines and adverse events (possible side effects) are filed in VAERS. Therefore, VAERS collects data on any adverse event following vaccination, be it coincidental or truly caused by a vaccine. The report of an adverse event to VAERS is not documentation that a vaccine caused the event.”

Later on that same page they state (again my emphasis):

“A report to VAERS generally does not prove that the identified vaccine(s) caused the adverse event described.  It only confirms that the reported event occurred sometime after vaccine was given. No proof that the event was caused by the vaccine is required in order for VAERS to accept the report. VAERS accepts all reports without judging whether the event was caused by the vaccine.”

It doesn’t get any clearer than that. According to the VAERS website itself, the database does not prove that vaccines were responsible, it does not establish causation, and it is not documentation that vaccines are dangerous. So you absolutely cannot use this database as evidence that vaccines are harmful and are causing injuries. That is a gross misuse of this database.

What this database is useful for, and what it is intended for, is to provide an “early warning system” that identifies potential problems that should be studied. In other words, scientists look at databases like this to identify topics that need to be examined more closely. Then, they do large, controlled studies on those topics to determine whether or not the vaccine is actually causing the problem. I cannot overstate the importance of this point. The database simply identifies topics to be studied, and the actual studies determine whether or not a causal relationship exists. You need to know the rate of the event in question with and without vaccines, while controlling all of the other variables before you can reach a causal conclusion, and VAERS simply does not provide those data.

Finally, it is worth mentioning that a number of anti-vaccine scientists (particularly the Geiers) have tried to mine VAERS for evidence that vaccines are dangerous, but that is an extremely problematic statistical design. Being systematic and carefully controlling potential confounding factors is essential in science, but because of the completely unsystematic and totally uncontrolled nature of databases like VAERS, it is really hard to get reliable, high-quality data out of them. In other words, these databases do not contain the controls that are necessary for assessing causal relationships or even for accurately assessing trends over time. As such, you should be extremely skeptical of any paper that is basing conclusions on VAERS.

Vaccine package inserts
Another anti-vaccine favorite is the package inserts. The Skeptical Raptor wrote an excellent and detailed post on these, so I will just hit the highlights. These package inserts contain a variety of information about the vaccine, but the part that anti-vaccers focus on is the list of adverse reactions. These contain a wide range of ailments, including things like autism. The situation is, however, very similar to the reports in VAERS.

The lists of adverse reactions in vaccine inserts simply contain any adverse events that were reported during clinical trials for the vaccine (sometimes they also include post-approval reports). To be fair, these are usually limited to events that were severe or were reported multiple times. In other words, the point of these lists is to provide information that is potentially clinically useful, thus they include any reactions which were either severe enough to be potentially concerning, or common enough that it is plausible that the vaccine was causing them. They do not, however, actually demonstrate that they vaccine caused the reaction (with the exception of reactions for which properly controlled trials were conducted). Just like the VAERs database, these lists are simply intended to guide doctors and future researchers, rather than providing evidence of causation.

In other words, if several of the test subjects in a clinical trial became ill and vomited several days after receiving the vaccine, then nausea would be reported as an adverse reaction, but that clearly does not mean that the vaccine causes nausea. It is entirely possible (even likely) that, during the trials, some patients would become sick from things that are completely unrelated to the vaccine. Similarly, if patients experienced headaches, those would get reported regardless of whether or not the vaccine actually caused the headaches. So, just as with VAERs, the fact that something is on the vaccine insert does not mean that the vaccine causes it.

Also, as with VAERs, you don’t have to take my word for this, because the package inserts often explicitly state that they do not provide evidence of causation. For example, here is an excerpt from the Tripedia DTaP vaccine insert (this is an insert that is often cited for including autism in the list; my emphasis).

“Events were included in this list because of the seriousness or frequency of reporting. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequencies or to establish a causal relationship to components of Tripedia vaccine.”

Also, note the fact that the adverse reactions were self-reported. This, once again, makes it very difficult to establish causation or accurate rates.

Finally, even if all of the events were causally related, you need to know their rate with and without vaccines before that information is useful. Everything has risks (including the decision not to vaccinate), so you always have to weigh the risks associated with taking an action against the risks associated with not taking that action. In other words, if a vaccine has a deadly side effect, but that side effect only occurs in 1 in every ten million injections, then the risks associated with avoiding the vaccine will far outweigh the risks associated with taking the vaccine. So you absolutely have to know the rates before you can make a properly informed decision. Simply showing that X causes Y is not sufficient.

National Vaccine Injury Compensation Program (VICP)
Finally, we arrive at the VICP. This is a no-fault system that was set up to compensate families for injuries caused by vaccines, and anti-vaccers often cite its mere existence as evidence that vaccines are dangerous. There are several important points that need to be made here. First, vaccines do have side effects (as do all real medications). No one denies that, but the side effects are generally minor, and serious side effects are quite rare. So, the benefits outweigh the risks. Thus, simply showing that vaccine-injuries exist does not prove that vaccines are dangerous. As I explained in the package inserts section, you need to take the rate of side effects into account when assessing risk.

Second, the program was established because pharmaceutical companies were being bogged down with lawsuits, and there was concern that the vaccine supply would be jeopardized. Therefore, since settling is often cheaper than fighting a lawsuit, the government set up this program as a means of protecting the vaccine supply, and they set it up to be very generous to the public. As the Skeptical Raptor explained in detail in this post, the requirements for getting money from the VICP are greatly relaxed compared to traditional courts. Applications don’t have to prove that the vaccine manufacturer was at fault, nor do they have to prove that the vaccine caused the damage. Rather, they generally just have to show that it is plausible that the vaccine caused the damage, and this can often be accomplished by something as simple as having an “expert” testify and say that it is plausible (i.e., you often don’t need actual studies showing that vaccines can cause the side effect in question). In other words, the system is set up to give the benefit of doubt to the applicant. So the fact that someone received money from the VICP is not an admission that the vaccine actually caused the injury (i.e., this is a very different situation from being found guilty or liable in a traditional court).

Finally, and perhaps most importantly, even in situations where a particular court claimed that a vaccine actually caused an injury, that still does not count as valid scientific evidence, because lawyers, judges, etc. can easily reach incorrect conclusions. In other words, the fact that a particular judge awarded money for a claim of vaccine injury only shows that the judge in question thought that the vaccine caused the injury. It does not, however, indicate that the scientific evidence shows that the vaccine caused the injury (i.e., this argument is a form of the appeal to authority fallacy).


Conclusion

In short, neither VAERS, nor the package inserts, nor the VICP provide evidence that vaccines are dangerous. VAERS and package inserts simply show adverse events that were reported following a vaccination, but they do not actually demonstrate that the vaccine caused the event in question. Indeed, both sources even state that the fact that an adverse event was included in them does not mean that the vaccine actually causes that event. Similarly, the VICP is a no-fault system, and applicants do not have to demonstrate that a vaccine caused the injury for which they are seeking compensation. Rather, they simply have to provide some evidence (such as expert testimony) that it is plausible that a vaccine caused the injury. Thus, none of these sources provide evidence of causation, so none of them can be used as evidence against vaccines. To be clear, vaccines do have side effects, as do essentially all real medications; however, to actually know which side effects are caused by vaccines, you need properly controlled studies, not glorified anecdotes. Further, even when a causal relationship has been demonstrated, you also have to consider the rate at which the injury occurs. Every decision has risks (including the decision not to vaccinate), and although vaccines do have complications, serious side effects are extremely rare and the benefits are extremely high. Therefore, the benefits of vaccinating outweigh the risks, and vaccinating your children will give them the best chance of living long, healthy lives.

Related Posts

Citations

Dorit Rubinstein Reiss. 2015. National vaccine injury compensation program facts. Skepticalraptor.com. Accessed 25-July-2016.

 VAERS Data. Vaccine Adverse Event Reporting System. vaers.hhs.gov/data/index. Accessed 25-July-2016.

Skeptical Raptor. 2016. Argument by vaccine package inserts — debunking myths. Skepticalraptor.com. Accessed 25-July-2016,

Sanofi Pasteur. 2005. Diptheria and Tetanus Toxoids and Acellular Pertussis Vaccine Absorbed. Tripedia. Fda.gov. Accessed 25-July-2016.

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Sinking Noah’s Ark Part 2: The Order of the Fossil Record Confirms Evolution’s Predictions

In this post, I am going to explain a line of evidence that both convincingly supports evolution and refutes the notion of a world-wide flood. I am, of course, referring to the ordering of the fossil record. If you go to just about any country and dig a deep enough hole, you will find that the soil is organized into geological layers, each of which has distinct properties and contents. According to creationists, the majority of these layers formed during Noah’s flood; whereas scientists argue that these layers represent different time periods in earth’s history. Creationists would have you believe that both of these explanations are simply “interpretations” of the data, but as I will demonstrate, that statement is erroneous because the scientists’ explanation is a logical deduction that started with the evidence, then drew a conclusion, whereas the creationists’ explanation is ad hoc and is simply trying to make the evidence fit a preconceived view.

This post ended up being quite long, so you can use the links below to jump around to different sections.

Note: In this series, I am discussing science, not religion. There are many people who both believe the Bible and accept evolution. So I am not trying to disprove the Bible, turn people into atheists, etc. Rather, I am simply explaining the scientific evidence for evolution (see Part 1 for more details). 

Note: in order to make this post as easily understandable as possible, I am going to try to limit the use of jargon and proper names for geological periods, eras, epochs, etc. I will instead use very crude terms like “dinosaur layers,” rather than “Triassic, Jurassic, and Cretaceous.” Although less precise, I think that this strategy will make it easier to convey my meaning without people getting lost in terminology.


Contrasting the predictions of creationism and evolution
Science is all about making and testing predictions, which is part of why it is so powerful. Before doing an experiment, we can state what we should observe if our hypothesis is true, then we can reject or fail to reject that hypothesis based on whether or not our predictions come true. So let’s apply that type of reasoning to this situation.

Evolution’s predictions
First, let’s look at the predictions of evolution. If evolution is true and life on earth has gradually evolved over billions of years, then we should see that reflected in the fossil record. The deepest layers should only contain fossils of microscopic organisms, and as we move up to more recent layers, we should eventually get multi-cellular marine invertebrates, then fish, then amphibians, then reptiles, then mammals and birds. Further, even within those major groups, we expect to see gradual changes, and most of the modern animals that we see today should only be represented in the uppermost levels (Figure 1A).

There are several important things to note about this prediction. First, it is quite an extraordinary prediction. To borrow a classic example, all that it would take is one Precambrian rabbit to completely refute our current understanding of evolution and the history of life on earth. In other words, if we found fossils that were out of order (e.g., birds before the first reptile layers, amphibians before fish, fish in the oldest layers etc.) that would shatter our understanding of evolution. By that same token, however, finding a very consistent order in all of the thousands of fossil beds from all around the world would provide exceptionally strong evidence for evolution, because we only expect that to occur if evolution is actually true. Think about this way, if God actually created all of the kinds of animals and they all lived at the same time (as creationists argue) what are the odds that we would never find a modern mammal in anything but the uppermost layers? Why is there such a distinct pattern in the fossil record if everything lived together?

The second thing to note about this prediction is that it was largely a priori. In other words, when Darwin and other early biologists first proposed the basic framework of evolution, they had an extremely incomplete fossil record. However, based on the limited fossils that they had, as well as comparisons of embryology, morphology, etc. they thought that the progression went from single-celled organisms to multi-cellular marine invertebrates, to fish, to amphibians, to reptiles, to birds and mammals. In other words, this evolutionary sequence was predicted before we had most of the fossils that we have today. Thus, this is not a situation where scientists are looking at the fossils and trying to make the patterns fit evolution. Rather, the patterns were predicted beforehand and scientists are simply seeing whether or not the patterns fit the predictions. Additionally, this same pattern has been confirmed by intermediate fossils, genetics, and multiple other lines of evidence. So, once again, this is an extraordinary prediction because everything rests on it. Finding just one fossil that was substantially out of place would force us to rethink everything.


Creationism’s predictions
Creationism makes radically different predictions. According to creationists, all of the major “kinds” of organisms were alive prior to the flood (possibly minus a few that went extinct between creation and the flood, but those most likely wouldn’t have fossilized; see Part 1 for an explanation of “kind” and why I am using that term). During the flood, essentially all of the land animals that weren’t on the ark were killed and many of them were buried and formed the fossil record. Thus, essentially all of the fossils and sedimentary rock layers that we see today are the result of the flood.

Most creationists seem to subscribe to one of two schools of thought about how the flood formed the fossil layers. One common idea is basically a flash flood model. This proposes that the water levels rose extremely quickly and rapidly buried animals. Thus, most of the fossils formed early during the flood. The second school of thought proposes that many animals tread water for a while rather than being immediately buried. These animals eventually drowned, then floated for a while, before sinking and being buried as sediments fell out of the water. In other words, the flood would have churned up all sorts of sediment, and that sediment would have then fallen out of suspension and formed layers, trapping the bodies of dead animals in those layers. More often than not, I hear these two ideas combined, and this notion of lots of animals slowly being buried seems common.

Now, let’s think about these situations for a minute and make some predictions. If all of the major groups of plants and animals were alive at the same time (Figure 1) and were buried by a wall of water and mud that swept across the land (the flash flood model), then we would expect the fossil record to be a jumbled mess (Figure 1B). Flash floods aren’t exactly known for neatly sorting their victims by taxonomy, so we shouldn’t see any sort of a pattern (taxonomy = the classifications of living things [e.g., canines and felines represent two different taxonomic groups]). Rather, we should see that dinosaurs, modern birds and mammals, early amphibians, etc. are all mixed in together. In contrast, if animals drowned, floated, and slowly sank, then they should either be randomly scattered throughout the sediment layers, or possibly sorted by size. They should not, however, be sorted by taxonomy (you would not, for example, expect all of the dinosaurs to sink and get buried at the same time, since dinosaurs ranged in size from being smaller than a chicken to larger than a school bus).

Note: For creationism, I am using the term “prediction” loosely, because creationism is entirely retroactive. So when I say “the predictions of creationism” I mean the patterns that we would intuitively expect from a flood.

Figure1: Panel A shows what evolution predicts that the fossil record should like like, and panel B shows what creationism predicts (under a flash flood model). Note: both panels are overly simplified. In reality there are hundreds of layers, and I left out lots of steps. Also, I was simply illustrating the first time that each group appears rather than focusing on how long they persisted.

Figure1: Panel A shows what evolution predicts that the fossil record should like like, and panel B shows what creationism predicts (under a flash flood model). Note: both panels are overly simplified. In reality there are hundreds of layers, and I left out lots of steps. Also, I was simply illustrating the first time that each group appears rather than focusing on how long they persisted.



The evidence
It hopefully won’t surprise you to learn that the predictions of evolution passed with flying colors, while the predictions of creationism epically failed. No matter what fossil bed you go to anywhere in the world, you will find a consistent pattern and progression. This is an absolutely critical blow to creationism for a number of reasons.

First, really ask yourself how likely it is that you would see this pattern everywhere in the world if evolution isn’t true. Why, despite finding untold millions of fossils from thousands of sites from all over the world, have we never once found a mammal fossil in a layer that is older/deeper than the first reptile layer? For that matter, why do we never see modern mammal “kinds” fossilized alongside dinosaurs? Evolution tells that our modern families of mammals didn’t evolve until well after dinosaurs went extinct, but if they all lived at the same time (as creationists claim) then why were they never fossilized together? Why don’t we have birds in layers deeper than the dinosaur layers? We don’t we have reptiles in the same layers as early amphibians? Why do we have layers with nothing but marine invertebrates? etc. This pattern is so consistent and so remarkable that it is utterly inconceivable that it could have formed during a flood.

Second, there are other clues in these layers beyond simply the species that they contain. Look at the dinosaur layers, for example (Figure 1A). There are many places all around the world where you can dig below the dinosaur layers and find older sedimentary layers containing earlier reptiles, amphibians etc. According to creationists, most of those layers formed during the flood, but if you think about that for a second, a huge problem emerges. The dinosaur layers are on top of the other layers, which means that they should have formed after the lower layers, but the dinosaur layers are full of fossilized tracks, nests, and other things that make it clear that the dinosaurs were actually living when those layers formed. So how is that possible if those layers formed during the flood?

Think about the progression of events that would have to take place here. Step 1: The flash flood buries countless organisms and kills pretty much everything. Step two: Sediment slowly settles out and forms the lower layers. Step three: The dead dinosaurs go scuba diving under hundreds of feet of water and walk around under water on this newly formed sediment layer and build nests and leave behind footprints. Do you see the problem? Further, I used dinosaurs as an example because most people are familiar with fossilized dinosaur footprints, but we have plenty of footprints, eggs, nests, burrows, etc. from the other organisms in other layers as well. Indeed, these layers are full of things that make it clear that animals were living on the substrate when they died. This makes it abundantly clear that these layers could not have formed from sediment settling out during a flood. Animals were clearly alive and walking around to make those tracks, nests, burrows, etc. which makes absolutely no sense if those layers were formed from sediment settling out under hundreds of feet of water after all of the animals had already drowned! Additionally, we find clear evidence of plants growing in the layers, consistent pollen patterns, etc. When you actually look at the details of the fossil record, it is abundantly clear that it couldn’t have formed during one massive storm (you can find more details with good sources at this post by talkoriginsorg).

Finally, realize that not only are the fossils in these layers consistent, but their dates are as well. In other words, when we radiometrically date these layers, the deepest layers are always the oldest. If they had all formed during the flood, however, then they should all be the same age. Now inevitably, someone is going to argue that radiometric dating isn’t reliable, but those arguments have no scientific merit. I explained this in more detail here and you can find a good essay at Answersinscience.org, but in short, scientists aren’t “assuming” that decay rates are constantly any more than we are “assuming” that the speed of light is constant. The decay rate is simply a physical property of the chemicals (in fact, there is this fun thing known as the “law of radioactive decay” which mathematically describes the decay rate). Similarly, the other “assumptions” that creationists accuse scientists of are actually logical inferences that are supported by numerous observations. Additionally, even if you choose to believe that radiometric decay rates are not reliable, doesn’t it seem a bit surprising to you that the deepest layers always yield the oldest dates? I mean, if they were all formed at the same time, why does that pattern exist? In other words, you not only need a cogent argument to support the notion that decay rates were faster in the past, but you also need an argument to explain why the rates were consistently faster in the deeper layers (note: please read this article by talkorigins.org before claiming that the dates from the top of the Grand Canyon are older than the dates from the bottom).

As should now be obvious, the evidence is overwhelmingly supportive of evolution and thoroughly refutes the notion of Noah’s flood, but that doesn’t stop creationists from trying to twist the evidence to make it fit their view. So, in the remainder of this post, I want to look at creationists’ responses and counter arguments. Before I do that though, I want to make one thing absolutely clear. For any explanation to actually be reasonable, it needs to not only explain why there are different layers, but also why they are consistently sorted into exactly the order that evolution predicted. Remember, embryology, genetics, transitional fossils, morphology, and physiology, all predict the pattern that we see. So how and why did a flood manage to not only sort animals, plants, etc., but also sort them into precisely the pattern that is predicted by evolution? Also, this explanation must be supported by actual observations and data. It cannot be some purely speculative made-up solution (otherwise it will commit an ad hoc fallacy).


Creationist responses

1. But there are places where the geological column is out of order
This claim is only true if you cherry-pick and don’t look at the full data. There are lots of things that can cause layers to shift after they are formed. For example, layers may slide along fault lines, resulting in an old layer ending up on top of a young layer (e.g., if you dig down along the dashed lines of Figure 2B you would find that the layers are out of order). Folding is another process that can cause an old layer to move on top of a young layer. Importantly, however, both of these processes leave obvious signs behind, and when we look at sites as a whole, we find things like Figure 2B, which clearly shows that they layers were formed in their correct order, and they have just been shifted afterwards. These geological processes are extremely well understood and any introductory geology book will cover them.

To put this another way, when you look at things like faults and folds, it is very obvious that the layers shifted after they were formed. Indeed, most creationists say that these layers formed early in the flood, then shifted later in the flood, which means that creationists are still stuck explaining why the layers formed in such a precise order to being with. In other words, the layers are technically out of order at these sites, but they aren’t out of order in a way that conflicts with evolution or supports creationism.

Figure 2: A simply illustration of how layers can shift along fault lines (the diagonal lines). Layers can form (A) and later shift because they are on faults (B). These can cause inconsistencies if you dig at precise spots (such as the dashed lines), but those inconsistencies disappear when you look at the whole site.

Figure 2: A simple illustration of how layers can shift along fault lines (the diagonal lines). Layers can form (A) and later shift because they are on faults (B). These can cause inconsistencies if you dig at precise spots (such as the dashed lines), but those inconsistencies disappear when you look at the whole site.

 

2. The geological column isn’t real because we never see it all in one place.
The geological column simply refers to the column of sediment layers that I have been talking about throughout this post, and the argument is that there are no locations where we see the entire thing with every single layer in a single place, therefore it is not a real thing.

Figure 3: There are only a few places where the entire geological column is at a single site, but that is not a problem because the pattern is consistent everywhere, so we can piece it back together.

Figure 3: There are only a few places where the entire geological column is at a single site, but that is not a problem because the pattern is consistent everywhere, so we can piece it back together.

First, that claim isn’t true. There are places where we can see the whole thing (details and sources are in this article by noanswersingenesis.org.au). Indeed, even Answers in Genesis admits that is a real thing. Additionally, of course we don’t see the whole thing in most places, because we are talking about layers that are millions or even billions of years old and there are many factors that can prevent them from being persevered for that length of time. Erosion, for example, is quite good at removing layers. That’s not a problem, however, because we can piece together the pieces from sites all over the world and get a very consistent picture (Figure 3). Finally, and perhaps most importantly, this argument completely ignores the problem of the order of the layers. In other words, it is true that there are places where there are gaps and missing layers, but it is equally true that there are no places where things are out of order (see #1 above for a qualifier). If you look at Figure 3 again, we can have a site where we find layers of single-celled organisms and layers of fish but not layers of marine invertebrates, and that is fine as long as the single-cell layer is still below the fish layer, which it always is.

Note: When I say that there are sites with every layer, I do not mean every species. In other words, there are layers which we know are from the dinosaur time periods because they contain index fossils that are only found from dinosaur time periods, but they may not actually contain dinosaur fossils at every site.


3. Different layers contain different species as a result of animals running from the flood.
This argument is so laughably absurd that it is tempting to ignore it entirely, but it is so common that I feel like I should deal with it. First, this proposes a cartoon-like scenario where animals are running from a wall of water, but that is not realistic. When a large storm starts, most animals respond by hiding, not running. So as soon as the rain started, animals would have hunkered down in their burrows, tree hollows, caves, etc. and once the tidal wave hit, they would have been buried right where they were.

Second, let’s assume that they did all try to outrun the flood. That still can’t explain the fossil record because its sorted by taxonomy, not speed. For example, this argument proposes that every single individual of every single modern mammal family was faster than every single individual of every single dinosaur species. Surely a velociraptor could have outrun a giant ground sloth, so why did raptors die out several million years before the first ground sloth fossils? Similarly, why don’t turtles show up until a bit over 200 million years ago? Why are sauropods (the giant long-necked dinosaurs) and tyrannosors found in the same layers together? Am I honestly supposed to believe that they could run at the same rate? What about babies and old individuals? Surely there would be lots of baby birds in nests, baby mammals in burrows, etc.

Third, even if everyone tried to run, and somehow new born puppies outran T-rex, there should still be evidence left behind. For example, if you go to just about any natural pond, you can find footprints of ducks, herons, and other birds all over the shallow areas. So why don’t we find those footprints around the ancient bodies of water where we find the fossils of the first amphibians? Those ponds should have been great places for birds to forage.

Fourth, although I have been talking about animals, we can clearly see the same type of progression in plants. Anyone care to explain to me how they ran from the flood?
Fifth, this argument makes absolutely no sense because we find these layers at the same sites. In other words, this isn’t a situation where at the most inland locations we find nothing but modern animals, and a near the coast we only early amphibians. Rather, you can go to locations all around the world, where you can start digging at a single site and see the progression as you dig. The Grand Canyon is a great example of this. As creationists readily admit, you can go there and see the progression of fossils as you hike down into it. So this clearly isn’t a matter of animals running, because if that was the case, they shouldn’t be fossilized at the same sites.

Finally, for most of these major groups (like dinosaurs) we have them from all over the world. So how exactly did modern mammals run to a location with no dinosaurs when dinosaurs were everywhere?


4. Different taxa lived in different geographical regions
There are two basic versions of this argument, but they both start with the same premise. Namely, they claim that the distinctions between the different taxa in the different layers are because they didn’t live in the same geographical regions. In other words, you had a region with nothing but marine invertebrates, a region with bony fish and early amphibians (but no reptiles, birds, or mammals), another region with dinosaurs, primitive birds, and small rodent-like mammals (but not modern birds or mammals), etc. (Figure 4A).

First, that’s just not how ecology works. If you go just about anywhere in the world you can find birds, mammals, reptiles, and amphibians (as well as fossils of extinct groups, like dinosaurs). The only exceptions are extremely cold areas and a handful of remote islands (also, most amphibians don’t like the ocean). However, even in those cold areas, you can still find birds and mammals, which is really important because they are the two groups that are the most restricted in the fossil record (with regards to the depth of the layers that they occur in). Indeed, you can find birds pretty much everywhere. It doesn’t matter if you are on the coast, in the desert, in a rainforest, in Antarctica, or in the middle of the ocean, there are birds. So this notion that there were tons of massive areas that had absolutely no birds is utterly absurd. Similarly, how does one get tons of marine environments that are totally free of fish? That’s just not something that happens. Additionally, why would there have been tons of aquatic environments with amphibians but no reptiles? I could go on, but hopefully you get my point: the type of taxonomic separations that creationists are proposing here are ludicrous and conflict with everything that we know about ecology.

To be clear, different species and groups of animals certainly have geographic and ecological restrictions. For example, you can’t find kangaroos anywhere but Australia and a few islands, but that’s not what we are talking about here. We aren’t talking about limits to the ranges of species or families, rather we are talking about massive taxonomic units. In other words, we aren’t talking about never finding a kangaroo with a dinosaur, rather we are talking about never finding any modern mammal with a dinosaur. To give another example, there are families of birds that only live in rainforests, families that only live in deserts, etc. but the problem isn’t that we never find one specific family of birds in the early layers. Rather, the problem is that we never find any birds in the early layers, and that is a huge problem for creationism, because although certain families have restricted ranges, you can find some sort of bird anywhere in the world. In other words, creationists generally argue that these groups existed because of ecological differences, but that is nonsense because all of the major groups of animals have representatives in essentially all of the major ecosystems. Further, we can see that variation in the fossil record. Dinosaurs, for example, occupied an extremely diverse range of habits. Additionally, keep in mind that creationists are proposing not only that animals lived in these bizarre taxonomically constrained geographic groups, but also that these groups just happened to perfectly match the predictions of evolution (that’s quite a coincidence).

Second, creationists are generally adamant that the flood would have been extremely violent, with ridiculously strong currents that carried sediment and debris for hundreds or even thousands of miles. So even if we accept that animals were living in these taxonomic groups, surely some of them would have been swept up by the flood and deposited into a different group. How exactly did a flood as violent as the one that creationists describe preserve such a perfect order?

Third, we still have the problem that the fossils of these groups can be found at the same sites. Again, you can go to a site, dig a hole, and observe the changes as you go down. Indeed, we find fossils of all of the major groups that we have been talking about from all over the world. So we know that they lived in the same areas, because we find their fossils in the same areas (just at different time periods).

This brings me to the next major problem. As I explained at the start of this post, we would expect a flood to either form a massive layer that contains most of the fossils (from a flash flood), or many stacked layers (from dead animals slowly settling out), but we know that the fossils weren’t formed from animals slowly settling out because of all the footprints, nests, etc. that could not have formed underwater. This leaves us with the flash flood model, but that model shouldn’t have formed stacks of fossils. So how do we get the stacks?

Figure 4: An illustration of the absurd way in which some creationists think that the fossils formed. (note: some creationists argue that the single cell layers pre-date the flood, which is slightly inaccurate from what I have depicted).

Figure 4: An illustration of the absurd way in which some creationists think that the fossils formed. (note: some creationists argue that the single cell layers pre-date the flood, which is slightly inaccurate from what I have depicted).

This is where creationists seem to split into two camps. One argument, as put forth by Andrew Snelling on Answers in Genesis, argues that the layers are simply the order that things were buried in. In other words, as the sea level rose and covered the land in water, the amphibians lived closest to the shore and were the first land animals to be buried, then the population of reptiles was hit next, etc. (Figure 4A). There are several problems with this (beyond the ones that I’ve already pointed out). First, for this to work, not only do we need to have all of the animals living in distinct and precise taxonomic groups, but those groups have to be carefully spaced in increasing order of complexity, and of course, this order and grouping has to be consistent every single place on the planet (that’s hardly a reasonable assumption). Second, this still doesn’t explain how you get layers. If animals were spaced like this, then you should still have once giant fossil layer, it should just vary from one region to the next (Figure 4B), and, in fact, there should be a lot of spill-over from one layer to the next as the flood would almost certainly have carried some carcasses with it, rather than instantly burying them. As far as I can tell, creationists are envisioning a situation like Figure 4C-G, where the flood forms layers as it goes, and magically scoops up each successive layer and adds it onto the massive stack of layers that it is carrying (while still carefully preserving footprints, nests, burrows, etc.). Last time I checked, floods don’t do that.

The second school of thought tries to solve this problem by basically arguing that everything initially formed one fossil layer, but then that layer got broken up and shifted on top of itself multiple times, resulting in the layers that we see now. There are several things to note here. First, although layers can shift around (see #1 above), they don’t do so in the type of massive, full scale way that creationists are proposing. They simply fold on top of each other or slide along fault lines, but creationists are proposing that everywhere in the world, hundreds of layers managed to neatly slide on top of each other, without leaving behind any evidence of having done so, and while perfectly preserving the order predicted by evolution. Just the idea that pretty much every layer everywhere in the world was shifting over or under multiple other layers is pretty far-fetched. Given that we find layers pretty much everywhere, it seems like that would cause a huge deficit of layers (e.g., if the Grand Canyon formed from hundreds of layers shifting on top of each other, then surely there would be massive lowlands all around it where those layers used to be). Also, realize that we aren’t talking about small shifts. In cases like the Grand Canyon, we have hundreds of layers, each of which stretches for hundreds of miles.

Additionally, and perhaps most importantly this still hasn’t explained the order of the fossil record. This argument expects me to believe not only that animals lived in these ridiculous taxonomic groups that are completely unlike anything that we have ever actually observed, but also that every single time that plates shifted, they did so in precisely the order that evolution predicted. Think about for a second. Even if you believe everything up to the point of the shifting layers, how likely do you actually think it is that there was never a case of a mammal or bird layer shifting under a dinosaur layer, a reptile layer shifting under an amphibian layer, an amphibian layer shifting under a fish layer, etc. (again, see #1 for a qualifier)? This argument is nothing more than a series of utterly ridiculous assumptions. You might as well say that aliens did it, because that argument would be just as plausible.

Finally, let’s apply our tests for ad hoc fallacies to these arguments. Is there any reason to think that animals lived in these amazingly consistent taxonomic groups other than a desire to believe in the flood? No! There is absolutely no scientific basis for this claim. Similarly, is there any reason to think that all of the fossil layers shifted over top of each other in exactly the order predicted by evolution other than a desire to believe in the flood? Again, no! The only way that anyone would ever believe either of those claims is if they were already convinced that the flood was true. These arguments perfect examples of ad hoc fallacies. They are logically invalid and must be rejected.


Creationist counter arguments
Not to be outdone, creationists try to fall back on “problems” with the fossil record, or “inconsistencies” with the predictions of evolution. So let’s briefly look at some of those.

1. There are sea shells on the highest mountains
It is true that you can find fossils of marine organisms on many of the highest mountains, and creationists would have you believe that this is evidence that those fossils were put there by the flood. In reality, however, our understanding of the history of planet earth suggests that many of our current continents were once submerged beneath giant oceans, and mountains rose as the earth’s plates moved and pushed together. Thus, we expect those fossils to be there.

The argument that creationists are making here is actually an example of a logical fallacy known as affirming the consequent. It takes the form:

  • If A then B
  • B therefore A

The problem is that B can have multiple causes. In this case, creationists are saying:

  • If the flood is true (A) there should be shells on mountains (B)
  • There are shells on mountains (B) therefore the flood is true (A)

The problem is that scientists could make the following identical argument:

  • If our understanding of earth’s history is true (A) there should be shells on mountains (B)
  • There are shells on mountains (B) therefore our understanding of earth’s history is true (A)

Note: affirming the consequent fallacies can be avoided by making exclusive predictions. For example, evolution’s prediction that we should see the gradual progression of fossils is an exclusive prediction, because it is not something that we expect to see under any circumstance other than evolution. Thus, the argument takes the form:
1. If and only if A then B
2. B therefore A is the most likely solution
As such, no fallacy is committed.


2. Many fossils look like they were formed by a flood
It is true that many fossils appear to have been formed in floods, but that doesn’t mean that they were formed in one massive flood (regional floods are certainly a real thing). Indeed, if you understand even the basics of how fossils form, then you should realize that floods are one of the best ways to form fossils. So we expect that many fossils will have been formed during floods, because that’s how fossils form! To put this another way, Ken Ham is very fond of saying that if the flood was true, we should see “millions of dead things buried in rock layers laid down by water all over the earth” and we see “millions of dead things buried in rock layers laid down by water all over the earth.” Therefore, the flood is true. However, if evolution was true, then we should also see “millions of dead things buried in rock layers laid down by water all over the earth.” Can you spot the logical fallacy that creationists are committing? (hint: it’s the same fallacy that was in #1 above).


3. But we have fossils of human footprints next to dinosaurs
No we don’t. All of those have either been hoaxes or miss-identifications. Even major creationist organizations admit this.


4. But what about living fossils that are in the fossil record from “millions” of years ago but are still alive today?
First, just to get definitions straight, a living fossil is an organism that is present today and is almost identical to ancient fossils (the exact age required isn’t precisely defined). We actually have multiple examples of these (horseshoe crabs and coelacanths are probably the two most famous), but I don’t understand why creationists think that these are a problem for evolution. There is nothing in evolutionary theory that states that an organism can’t evolve a very good body plan, then maintain that plan for millions of years. To be clear, if a huge portion of today’s animals were living fossils, that would be different from the expectations of evolution, but it still wouldn’t refute it, and the few dozen living fossils that we have simply aren’t a problem for evolution. Quite simply, they don’t contradict evolution in any way shape or form, because the theory of evolution never states that species can’t exist for hundreds of millions of years. So this is a strawman fallacy.

Additionally, I would argue that the relative scarcity of living fossils is an enormous problem for creationism. Think about it, if animals can’t evolve beyond their “kind,” and all “kinds” were both present before the flood and were carried on the ark, then shouldn’t almost all of our animals be living fossils? In other words, if almost the entire fossil record formed during the flood, and all of the “kinds” of land animals in that record were on the ark, then most of our current animals should be living fossils. Sure, some will have gone extinct since the flood, but only a very tiny portion of our current species are living fossils, which is exactly the opposite of what we would expect if creationism was true.


5. But we have found fossils that are out place
Creationists often like to cite examples of fossils that were found outside of their usual layers, but there are several important things to note about that claim. First, many of the examples that they cite are incorrect. For example, they often claim that pollen can be found in fossils that date to time periods before pollen producing plants existed. Although technically true, an examination of those fossils makes it really obvious that the original fossils were exposed to the pollen long after they had formed. In other words, the fossils were contaminated with pollen from a later time period. Even many creationists admit this. So whenever you hear these claims, you should carefully fact check them to make sure that they add up.

Second, the claims that do actually stack up are always off by just a few million years, which once again, isn’t a problem for evolution. For example, finding out that an animal actually evolved ten million years earlier than we had previously thought it did is not a problem for evolution. That just means that our dates were slightly off (and yes, when we are dealing with timescales of billions of years, a few million is “slightly off”).

The only way that these fossils would be a serious problem for evolution is if they were actually out of order. In other words, you need something like a fully developed bird before the first proto-bird fossils (no, Confuciusornis is not an example of that, it had fossil predecessors). You need a turtle that was swimming with the first amphibians or a modern mammal that was chilling with the dinosaurs. Once again, all it would take is one Precambrian rabbit to bring our understanding of evolution to its knees, but no fossils like that have ever been found.

Just to be 100% clear here, this isn’t an argument from ignorance fallacy. Rather, if the flood was true, then finding these fossils mixed together should be the norm not the exception. In other words, if all of these organisms lived and died at the same time, then we shouldn’t find a pattern that perfectly matches evolution other than a handful of exceptions. Rather, we should find a complete and total lack of a pattern. There should be no correlation between the predictions of evolution and our observations in the fossil record. So that fact that we have never once found a fossil that was significantly out of order (despite having millions of fossils from thousands of fossil beds from all over the world) provides extremely clear evidence that the flood is false. Think again about the fact that all of the pre-reptile layers are completely free from any birds or mammals, and even within the reptile layers, there is a clear gradual progression. That makes absolutely no sense if the flood is true.


6. What about the cases where a single fossil stretches between several layers. How is that possible if one of those layers is millions of years older than the other?
This argument refers to “polystrate fossils” which are fossils that are found upright, sticking through several levels. Usually these are trees, and there are several important things to note about them. First, the layers with these trees aren’t actually millions of years apart. Second, we have understood how they form for well over 100 years. For the sake of time, I won’t go into the details, but the short version is that these trees were rapidly buried by local floods. (regional floods obviously do happen).

Additionally, when we look at these trees, we can see that one of the layers is simply the clay layer that the roots are sticking into (i.e., the layer it was growing on), and the next layer up is often a coal layer (which could have been formed when the plants around the tree were buried). The third layer is then simply the layer the buried the tree and surrounding vegetation. Finally, despite creationists’ claims, for some tree species, having the trunk partially buried is not a death sentence. Indeed, we have examples where trees were partially buried, but continued to grow for years before being fully buried in a second regional flooding event. We can tell this because of the formation of new roots growing out of what was previously the trunk. So in fact, these fossils are a huge problem for creationists, because if these trees were actually buried rapidly in a global flood (as creationists claim), then how did the trees form that second root layer?

A final example that creationists like to cite is a “kamikaze” ichthyosaur. This argument refers to a single fossil of an ancient marine reptile, where the skull sticks straight down through three layers. You can read the science of how this happened in the original article (Wetzel and Reisdorf 2007), but a big part of what happened was simply that the creature sank nose-first because of its canter of gravity, and its pointy noise sank deeply into the soft substrate (bodies of water often have incredibly soft, muddy bottoms that are easy to sink into). Also, many of the claims that creationists make (such as the idea that the layers are millions of years apart) are not in the original article, so they seem to be straw men. Finally, let’s flip this thing around and ask a different question. If the flood was true, and thousands of animals slowly sank and were buried in sediment, then why aren’t fossils like this the norm? Shouldn’t fossilized animals that stick through multiple layers be everywhere? Indeed, if the fossils and sediment layers came from the flood, then it is quite surprising that it is so rare to find fossils that stick through multiple layers.


7. Where are the missing links? If evolution is true, there should be lots of transitional fossils, so where are they?
They are everywhere! We have hundreds of clear transitional fossils; creationists just refuse to accept them as such (see this post for details). Further, these fossils show up exactly where we would expect them to. In other words, we see early fish-like amphibians before the modern amphibians that we have today, we see early dinosaur-birds before finding the modern birds that we have today, we find early reptile-like mammals before finding fossils of the modern mammals that we see today, etc.


Conclusion: Ad hoc fallacies and Occam’s razor
As I have shown in this post, the fossil record perfectly matches the predictions of evolution. Well over 100 years ago, evolutionary biologists predicted that all over the earth we should see a consistent pattern with the oldest/deepest layers containing single celled organisms, followed by multi-cellular marine invertebrates, followed by fish, followed by amphibians, followed by reptiles, and ultimately birds and mammals. That prediction has held remarkably true and provides extremely powerful evidence for evolution. In contrast to the predictions of evolution, creationists are retroactively trying to make the data fit their view, but in order to do that, they have to invent ridiculous solutions like proposing that the major groups of animals where geographically constricted and lived in taxonomic units. Given what we know about these animals today (e.g., birds are found everywhere, even Antarctica), and the fact that we find fossils of all of these groups from all over the world, this assumption is ridiculous. Additionally, they also have to assume that countless layers not only managed to shift over-top of one another without leaving behind the typical geological hallmarks of having done so, but also that every single time that this happened, the layers shifted such that the order predicted by evolution was maintained.

These arguments are classic ad hoc fallacies. They are ridiculous “solutions” that have no evidence to support them and would never be accepted by anyone who wasn’t already convinced that the flood was true. They are nothing more than baseless speculation and wishful thinking. To put this another way, creationists aren’t looking at the evidence and drawing a logical conclusion. Rather, they are starting with the conclusion that the flood is true, then they are inventing fanciful “solutions” to try to make the evidence fit that conclusion.

In closing, I want to remind everyone of one of the golden principles of both logic and science: Occam’s razor. This states both that you should always limit your assumptions and that the solution with the fewest assumptions is the most likely to be true. In this case, evolution is not making any assumptions. Rather, it made an extraordinary prediction that came true. In contrast, creationism is making a series of increasingly ridiculous assumptions. If you are a creationist, I want you to really think about whether or not the creationists’ arguments make sense. How likely do you really think it is that not only were all animals living in taxonomic groups that exactly matched the predictions of evolution, but their fossil layers also managed to get sorted into an order that perfectly matched evolution’s predictions? Wouldn’t it make more sense to just admit that evolution is correct?

Related posts

 

Citations

  • Gastaldo. 1992. Regenerative growth in fossil horsetails following burial by alluvium. Historical Biology 6:203–219.
  • Isaak. 1998. Problems with a global flood 2nd ed. talkorigins.org. Accessed 12-July-16.
  • Issak (ed) 2003. The Talk Origins Archive: Claim CC341. Talkorigins.org. Accessed 18-July-16.
  • MacRae. 1997. “Polystrate” tree fossils. Ralkorigins.org. Accessed 12-July-16
  • Morton. 1996. The geological column and its implications to the flood. noanswersingenesis.org.au. Accessed 11-July-16
  • Snelling. 2010. Order in the fossil record. Answer Magazine. Answersingenesis.org. Accessed 12-July-16.
  • Stassen. 2003. A criticism of the ICR’s Grand Canyon dating project. talkorigins.org. Accessed 12-July-16
  • Wetzel and Reisdorf. 2007. Ichnofabrics elucidate the accumulation history of a condensed interval containing a vertically emplaced ichthyosaur skull. SEPM 88:241–251.
  • Woolf. An essay on radiometric dating. Answersinscience.org. Accessed 10-July-16
Posted in Science of Evolution | Tagged , , , , | Comments Off on Sinking Noah’s Ark Part 2: The Order of the Fossil Record Confirms Evolution’s Predictions

Sinking Noah’s Ark Part 1: Introduction

I'd be far more impressed with the Ark Encounter if it had been built by four people with hand tools. Image via Why Evolution is True

I’d be far more impressed with the Ark Encounter if it had been built by four people with hand tools. Image via Why Evolution is True

There has recently been a lot of hype over Answers in Genesis opening its latest attraction, the “Ark Encounter.” This life sized “replica” of Noah’s Ark is intend to be a tool to help spread the message of young earth creationism, which would be all well and good if it wasn’t for the fact that young earth creationism is scientifically ludicrous and demonstrably false. Therefore, in this series of posts, I want to go over several of the many lines of evidence which clearly show that a recent world-wide flood did not occur, as well as dealing with some of creationists’ arguments in support of the flood. Before I delve into those arguments, however, I want to use this post to explain why the flood is such an important topic. I often find that skeptics and scientists tend to ignore the flood when debating creationists, but I think that we should actually be focusing on it, because as I will demonstrate, the flood is absolutely essential to creationism and it is the easiest of their positions to convincingly debunk.

Note: As always, I want to be absolutely clear that I am not attacking religion. This blog is about science, not religion, so it is not my intention or purpose to debate whether or not there is a god, whether or not Christianity is true, etc. However, any time that a religion makes a claim about the physical universe, it has entered into the realm of science, at which point it comes under my crosshairs. There are plenty of people who both believe the Bible and accept that evolution is true, the earth is old, etc. (see posts here and here). So if you can reconcile your faith with science, then you and I won’t really have any problems. It is not, however, acceptable for you to allow your faith to trump science, and that is what I take issue with. So, for any creationists reading this, I am not asking you to abandon your faith. Rather, I am asking you to take a critical look at what you believe and make sure that it is consistent with scientific facts. Indeed, you already use science to interpret many passages of the Bible, so there is no reason for you not to apply those same hermeneutical principles to Genesis.

 What do creationists believe?
I often see skeptics wasting their time attacking straw men; therefore, I think that it is important at the outset to state exactly what it is that creationists believe regarding the flood. According to creationists, roughly 4,500 years ago, God grew so tired of mankind’s depravity that he decided to wipe out all humans (except Noah and his family) as well as all land animals (I have to wonder what the animals did to deserve that, but that’s beside the point). So, God told Noah and his sons to build a massive ark, into which God sent two of each “kind” of land animal (birds, mammals, reptiles, and possibly amphibians depending on which creationist you talk to). God then caused a massive storm during which it rained for 40 days straight and the entire planet was covered in water (even the highest mountains were covered). The flood rapidly buried many plants and animals in sediment, while others tread water before eventually drowning and being buried as sediment fell out of the water. Thus, the flood formed the vast majority of fossils as well as the geological layers that we see today (e.g., all of the layers of sedimentary rock that you see at places like the Grand Canyon were supposedly deposited by the flood). In total, the flood lasted for roughly a year, and once it was over, Noah released the animals from the ark, and they went forth to breed and repopulate the earth (and apparently not instantly eat each other).

That may sound simple, but there are several crucial points that need to be emphasised. First, creationists believe that all of the major kinds of land animal were alive prior to the flood and were included in the ark. So ever major group of animals that has ever lived (including dinosaurs) was alive before the flood and was included in the ark. That is going to become really important in coming posts.

Second, you have to understand what creationists mean by the term “kind.” According to them, Noah did not actually have two of each species on the ark. Rather, he had two of each kind on the ark. To them, a “kind” is roughly the same as the scientific term “family.” Thus, Noah did not have two tigers, two lions, two bobcats, two leopards, etc. Rather, he had two cats, because according to them, the cat family (Felidae) represents one kind. Following the flood, those “kinds” evolved into the species that we see today. This “kind” argument is actually extremely problematic for a number of reasons (for example, as I explained here, it is totally logically inconsistent), but it is nevertheless what they think, and it is important to understand that so that you don’t commit a straw man fallacy. In other words, I often see skeptics arguing that the flood is impossible because two of each of the millions of species of animals that are alive today could not have possibly fit onto the ark, but creationists don’t think that all of the species were there; rather, they think that all of the kinds were there. I have seen a lot of different estimates from them regarding how many “kinds” would have been present, but the numbers are usually less than 30,000. Again, you’re welcome to debate this notion of kinds, and in later posts I will show why two of each “kind” could not possibly have produced all of the species that we see today, but it is nevertheless what creationists believe, and you have to address their actual beliefs, not straw men.

The importance of the flood to creationism
If you want to debate creationists, you have to understand the flood, because it is a cornerstone of their view. For creationists, a literal world-wide flood is a “get out of jail free” card that they use to dismiss just about any evidence that the earth is old/evolution is true. Ask a creationist why dinosaurs aren’t around anymore, and the answer will be, “they couldn’t survive the environment after the flood.” Ask them where all of the fossils came from if the earth isn’t millions of years old, and they will say, “they formed during the flood.” How did the Grand Canyon form? “The flood.” How did varves form? “The flood.” etc.

To be clear, these arguments are horribly flawed and almost all of them commit ad hoc fallacies (more on that in a minute), but the point is that creationists rely heavily on the flood as their means of explaining away scientific evidence. So, by showing that the flood is impossible, you kick out a critical leg of creationism, and you defeat young earth creationism as a whole. In other words, if the flood did not occur, then creationists have no way to explain the fossil record, geology, etc.

Why debate the flood?
Beyond the importance of the flood to creationists, there is another really important reason why skeptics/scientists should focus on it. Namely, it is actually falsifiable. You see, many creationist beliefs simply cannot be disproved via science. Take, for example, the notion that God specially created all living things. We can look at the fossil record, genetics, biogeography, vestigial structures, etc. and see that they exactly match the predictions of evolution, but creationists can always respond to that simply by saying, “well God made it that way.” That statement is inherently unfalsifiable, because no matter how closely our observations match the predictions of evolution, it is always possible that for some unknown reason a cosmic being decided to create life in such a way that it looked like it had evolved. To be clear, that belief is not even remotely rational (in fact it commits another ad hoc fallacy), but it is not technically falsifiable because it invokes the supernatural, and the supernatural is outside of the realm of science.

In contrast, a literal world-wide flood is falsifiable because it would have been physical. Although creationists argue that God caused the flood, they generally argue that he simply triggered it, and the flood itself was an entirely physical event. As such, it is entirely within the realm of science and we can test it and potentially falsify it. In other words, if the flood occurred, then it should have left behind distinct pieces of evidence, so we can look at the evidence and see if it matches the predictions of the flood. This makes the flood a much better target for debate than creationism more generally.

Ad hoc fallacies
Ad hoc fallacies are one of the most common tactics used by creationists, and you will see them a lot throughout this series, so I want to spend a few minutes explaining what they are and how to spot them. These fallacies are generally responses to arguments rather than arguments themselves, and they have two key characteristics. First, they are designed entirely to plug a hole in an argument. In other words, they aren’t part of a broad conceptual framework nor are they things that you would intuitively expect. This brings me to the second key characteristic: you wouldn’t accept an ad hoc argument unless you had already accepted position that it was designed to save. In other words, they are invented solutions, and there is no reason to accept them other than that they let you maintain a view that you are fond of. If you are familiar with the literary construct known as “deus ex machina,” this is basically the debate equivalent. It is an unsupported solution that is pulled out of thin air.

Let me give you an example. Suppose that someone claims that a ghost is reliably being encountered in a certain house. So I go to the house with the person several times and never detect anything that could possibly be considered to be a ghost. When I ask my guide why this supposedly frequent ghost never shows up when I’m there, he/she responds, “it doesn’t like to come out in the presence of skeptics.” Do you see how that works? There is no logical reason to accept that response. It is not something that you would intuitively expect to be true. Rather, it is a made-up solution that does nothing other than “solve” a problem in the ghost hunter’s position, and it is a solution that I would never accept unless I was already convinced that ghosts were real (this is very similar to question begging fallacies, and they often occur simultaneously). This example also illustrates another common characteristic of ad hoc fallacies. Namely, they are often impossible to disprove. In other words, the claim that the ghost only shows up around believers is impossible to properly test, because people who weren’t already convinced that the ghost was real would need to be there to unbiasedly confirm or refute its existence.

Creationists commit this fallacy all of the time, so you should watch out for it, and there are two easy tests to detect it. First, examine whether or not a given response is backed up by actual data. For example, to explain the size of current coral reefs, creationists often claim that in the past they grew at many times their current growth rate. The problem is that there is absolutely no evidence that such a growth rate occurred or is even physically possible. Thus, this is a made-up solution. The second test is simply to ask yourself whether or not someone would accept that response if they were not already convinced of the thing being defended. For corals, the answer is again a resounding “no.” There is no scientific reason to think that corals used to grow substantially faster than they do now, so the only reason that anyone would ever accept that response is if they already thought that the flood was true/the earth was young, and they wanted to maintain that belief.

Conclusion/future posts
Now that we have the important introductory material out of the way, we can start on the actual arguments themselves, and there are many of them. In coming posts, I will be explaining the fossil record and geology, varves, more details on corals, genetics, and multiple other lines of evidence which clearly show that a world-wide flood did not occur. In addition to refuting the flood, many of these arguments also provide strong evidence that the earth is old and/or the theory of evolution is correct. If you are a creationist reading this, then I have just one simple request for you: I want you to seriously consider the possibility that you might be wrong. Many creationists, like Ken Ham, openly admit that no amount of evidence will ever make them change their minds, and if that is your position, then there is really no point in you reading any further. If, however, you a really interested in knowing what is accurate and factual, then I encourage you to lay aside your preconceptions and carefully consider the evidence and logic that I will be presenting.

If you are impatient and don’t want to wait for my posts, I recommend reading Moore. 1983. The impossible voyage of Noah’s Ark. Creation Evolution Journal 4:1–43. It is an excellent essay on many of the problems with the flood story.

Other posts in this series

 

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If cannabis and vitamin B17 kill cancer, why aren’t they approved by the FDA? Let me explain

cancer curesIt seems like hardly a week goes by without some news article claiming that a simple cure to cancer has been found. Similarly, social media is full of images like the one to right claiming that cannabis oil, vitamin B17, and a host of other things can kill cancer cells. However, more often than not, these claims are extremely misleading because the studies that are being referenced are usually in vitro studies (i.e., studies on cells in a petri dish) or, at best, animal trials, and both of those designs are extremely limited. As I will explain in this post, killing cancer cells in a petri dish, and safely killing cancer cells in a human body are two extremely different things. Indeed, many chemicals appear promising in laboratory trials but are later shown to be either dangerous or ineffective in clinical trials on humans. So you should be very skeptical of the news headlines, and you should be slow to jump to extreme conclusions (e.g., arguing that it’s a massive conspiracy by the government and pharmaceutical companies).

There are many types of cancer
The first thing to realize about any claim regarding a “cure for cancer” is that cancer is not a single disease. There is no one type of cancer. Rather, there are many different types of cancer, each of which behaves differently. Therefore, even if you successfully demonstrated that something could cure one type of cancer, you would not have demonstrated that it is effective against any of the other forms of cancer.

This is especially important to understand with regards to in vitro trials, because they are inherently limited by their use of cell lines. A “cell line” is a clonal population of cells that is maintained in a laboratory. To start a cell line, scientists take a single cell (e.g., a cancer cell) and grow it in the lab, resulting in it duplicating many times. This is very useful because the duplicates are exact copies of the original (barring any mutations). Thus, scientists can use cell lines to completely eliminate most confounding factors, and two different scientists working in different labs can do comparable research by using the same cell line.

Nevertheless, despite the obvious benefits of cell lines, they are also problematic because they limit the scope of your conclusions. Imagine, for example, that scientists find that chemical X kills cancer cell line Y in the lab. All that would mean is that X kills one particular line of one particular type of cancer. It may or may not work on any other cell lines or any other types of cancer. So you have to keep that in mind when you hear that a new study found a chemical that killed a particular line of cancer cells. The study may be right, but its results may not apply to anything beyond that particular cell line.

Killing cells in a petri dish and kill cells in a human are not the same thing
The next important point is that there is a world of difference between effectively killing cancer cells in a petri dish and effectively killing cancer cells in the human body. In the lab, you can put a large dose of the chemical directly on the cells, whereas in the human body, you have to either inject or ingest it, which is instantly going to dilute it. Further, your liver and kidneys will likely try to filter the chemical out, and it may interact with any one of a thousand other chemicals in your body. Remember, everything in your body is made of chemicals, and (with the exception of catalysts) chemical reactions change the chemicals by breaking or forming bonds. So you may have a chemical that is extremely effective in the lab, but in the body, it quickly reacts with other chemicals and changes into a chemical that is not at all effective at killing cancer cells.

The fact that something kills cancer cells does not mean that it is safe to use. Image via xkcd

The fact that something kills cancer cells does not mean that it is safe to use. Image via xkcd

Is it safe?
This is probably the most important point in this post. For a “cure” for cancer to really be effective, it has to both kill cancer cells and be safe for your other cells. Finding things that kill cancer cells is easy, but finding things that kill cancer cells without harming your other cells is very difficult. For example, flame throwers kill cancer cells, but that doesn’t make them an effective treatment. Similarly, gasoline will kill cancer cells, but I don’t recommend drinking it. Alcohol will also kill a plate of cancer cells, but in humans, it actually causes cancer! Laetrile (commonly known as vitamin B17) is another great example of this. There is some evidence that it can kill cancer cells in the lab, but it does so by releasing cyanide, which will kill your normal healthy cells just as quickly as it kills cancer cells.

This brings me to another important point: cancer is very difficult to treat because it is part of your body. Developing a drug that safely kills something like bacteria is comparatively easy because bacterial cells are biochemically very different from human cells. So to kill bacteria, you just have to develop a chemical that will interfere with biochemical pathways that are found in bacteria but not found in humans. Cancer is much more challenging because the cancer cells are simply mutated versions of your own cells. As such, they have most of the same basic biochemical pathways as your other cells. This makes it exceptionally hard to find a safe treatment, because most chemicals that kill cancer cells will also kill normal, healthy cells. This is a big part of why it is so hard to cure cancer, and it is a very important reason why you should be skeptical of claims that someone has found a cure for cancer. Unless they can explain exactly how that cure targets cancer cells without targeting normal cells, you probably shouldn’t believe them.

Finally, we have to remember that the dose makes the poison as well as the cure. So for a chemical to be an effective treatment, it is going to have to kill the cancer cells at a dose that is below the dose at which it becomes dangerously toxic to humans. Indeed, this is the balance that doctors try to find with our current treatments of radiation and chemotherapy. Cancer cells divide very rapidly, and those treatments are particularly good at attacking dividing cells, so they tend to do more harm to cancer cells than to your normal cells, but there is still collateral damage. In other words, the idea is to find a balance between having just enough of the treatment to kill the cancer cells, without killing too many of your healthy cells. This is extremely important to understand, because although some of the “alternative” cancer treatments might kill cancer cells, they probably kill your healthy cells as well, and because they haven’t been well-studied, we don’t know what the correct dose is. In other words, don’t assume that something is safe just because it has the label of “alternative medicine.” As I said earlier, B17 actually produces cyanide. So “alternative” treatments may not be safe, and they usually aren’t even treatments.

hierarchy of scientific evidence, randomized controlled study, case, cohort, research designThe hierarchy of evidence
The overarching point that I am trying to make here is that you should be skeptical about claims regarding cancer cures (and medicine and science in general). Whenever you hear a claim that something cures cancer, you need to take a good look at the evidence to see whether or not that claim is justified. More often than not, the claims are based on anecdotes, in vitro trials, and animal trials. I explained the problems with anecdotes at length here, and I have spent most of this post on in vitro trials, but animal trials suffer many of the same problems. Mice and rats are biochemically different from humans, and drugs often behave very differently in animals than they do in humans. For example, although avocados are generally considered to be safe for humans, they can be toxic to birds, mice, rabbits, rats, sheep, and a variety of other animals.

This is especially important for diseases like cancer, because, once again, there are many types of cancer that all behave differently, and cancers in rats may not be representative of cancers in humans. Further, just like the cell lines for in vitro trials, animal trials generally used inbred strains of mice/rats. In other words, family groups have been inbred to the point that they are all genetically identical (or at least nearly so). So, just as with in vitro trials, it is very difficult to generalize from animal trials. Indeed, it is very often the case that a drug appears promising in in vitro/animal trials but utterly fails on humans.

Because of all of the problems that I have been talking about, animal trials and in vitro trials are at the bottom of what we call the “hierarchy of evidence.” Not all experimental designs are equal, and some give much more reliable and applicable results than others. Animal trials and in vitro studies are considered to be very unreliable, and, therefore, they are intended simply as starting points for future investigation, and you should never draw strong conclusions from them. In other words, the more robust experimental designs (like cohort studies and especially randomized controlled trials) tend to be very time consuming and expensive. Therefore, scientists use the lower quality study designs to identify the drugs that are interesting enough to merit further investigation. So animal trials/in vitro studies are often the basis for starting a large clinical trial, but you should always base your conclusions on the results of the large clinical trials.

The point is that before you accept that something cures cancer in humans, you need to look at the studies to see if they actually have the ability to reach that conclusion. In almost every case, they don’t. For example, systematic reviews of B17 have found that there is insufficient evidence to conclude that it is either safe or effective at treating cancer in humans (Milazzo et al. 2007, 2015). Similarly, we just don’t have any good clinical data to suggest that marijuana is effective at curing cancer in humans. So in answer to the question of why the FDA hasn’t approved treatments like these, it is quite simply, because we don’t have compelling evidence that they are either safe or effective in humans. The whole point of the FDA is to make sure that treatments are both safe and effective before they are approved for general use, but that evidence is completely lacking for alternative cancer treatments.

Conclusion
In short, most of the time when you hear someone say that a chemical cures cancer, they are referring to an in vitro study, but those studies are extremely problematic. They can only show that a given chemical kills a particular cell line for a particular type of cancer in a petri dish. They don’t show that the chemical kills cancer cells generally, nor do they show that it is safe for humans, or that in the human body it will be able to reach the cancer cells without either being filtered out by the liver and kidneys or interacting with other chemicals. There are countless chemicals that kill cancer cells in a petri dish, but that doesn’t mean that they are either safe or effective at treating cancer in humans. Indeed, there are many chemicals, such as gasoline and arsenic, that will kill cancer cells in the lab, but that doesn’t mean that it is a good idea to ingest them. In fact, many of the “cures” for cancer are very dangerous to healthy human cells (e.g., vitamin B17 works by producing cyanide and MMS is an industrial bleach). So the reason that these “alternative treatments” aren’t FDA approved is simply that they have not been shown to be either safe or effective in humans, and it is the FDA’s job to make sure that treatments are not approved until they have met those two criteria. The point is that whenever you hear a claim about a cure for cancer, you should be skeptical, and you should check the sources and see if the claim is actually backed up by high quality studies that are capable of reaching that conclusion.

Related posts


Literature Cited

Milazzo et al. 2007. Laetrile for cancer: a systematic review of the clinical evidence. Supportive Care in Cancer 15:853–595.

Milazzo et al. 2015. Laetrile treatment for cancer. Cochrane Database of Systematic Reviews.

Online references
Alcohol and Cancer Risk. National Cancer Institute. Cancer.gov. Accessed 3-July-16.

Avacado. The Merck Veterinary Manual. Merkvetmanual.com. Accessed 4-July-16.

Laetrile/Amygdalin (PDQ)-Patient Version. National Cancer Institute. Cancer.gov. Accessed 3-July-16

Laetrile (amygdalin, vitamin B17). Cancer Research UK. Cancerresearchuk.org. Accessed 3-July-16.

 

Posted in Nature of Science, Vaccines/Alternative Medicine | Tagged , , , , , | 9 Comments

Why are there so many reports of autism following vaccination? A mathematical assessment

The idea that vaccines cause autism is one of the most persistent myths that I have ever encountered, and it seems that no amount of evidence will ever cause it to disappear. Indeed, I recently wrote a lengthy post in which I thoroughly reviewed the scientific literature on this topic, and I showed that there are no high quality studies supporting this myth, but there are multiple very large studies that debunked it. Nevertheless, many people responded to the post by insisting that vaccines must cause autism because there are so many cases of parents reporting the onset of autism shortly after vaccinating. They were adamant that these anecdotes could not be chance results and must mean that vaccines cause autism. To quote one commenter,

“How can you sit there and say that observing an adverse reaction AFTER a vaccine is given doesn’t mean it was the vaccine? So, what…? It’s just a random coincidence? I think not.”

Given how common this argument is, I want to look at these anecdotes and what they actually mean, and, as part of that, I want to actually do some math and calculate the probability of a child developing autism shortly after being vaccinated if the vaccine isn’t responsible. In other words, I want to calculate the odds of observing autism “AFTER a vaccine is given” just by “random coincidence.”

The problem with anecdotes
Anecdotes are extremely problematic for multiple reasons. I’ve explained them in detail before, so I will just discuss the core problem here. Namely, using anecdotes as evidence of causation commits a logical fallacy known as post hoc ergo propter hoc. This fallacy occurs whenever you say “X happened before Y, therefor X caused Y” (e.g., “Billy was vaccinated shortly before showing the first signs of autism, therefore the vaccine caused the autism”). The problem is that just because one thing happens before something else does not mean that the two are related. It could, in fact, be a complete coincidence (more on that later). Many people often become very indignant when I say that (as the commenter that I quoted did), but these aren’t arbitrary rules that I have made up. This is just how logic works. The fact that X happened before Y does not in any way demonstrate that X caused Y. You need additional information (such as knowledge of confounding factors) before you can assume that they are related.

Here is an example that I often like to use. Imagine that I fill my car with fuel and it breaks down a mile later. Can I assume that the fuel was bad and that’s what made my car break down? Obviously not. There are lots of parts on a car that can break, and it is entirely possible that one of them just happened to break shortly after fueling up. In other words, it could my be a complete and total coincidence. Think about it, thousands of people fill up their cars every day, and thousands of people break down every day. So it is inevitable that there will be lots of cases where someone just happens to break down right after filling up. The fact that fueling up happened before breaking down does not mean that fueling up caused me to break down, and that exact same logic applies with vaccines and autism.

To give another example, imagine that someone takes a new medication, then has a heart attack the next day. Can we conclude that the medicine caused the heart attack? No, we can’t. Heart attacks are extremely common, so it shouldn’t be surprising that, just by chance, some people will have heart attacks shortly after taking a medicine, even if the medicine didn’t cause the heart attack.

How to study anecdotes
Although anecdotes are not very useful as evidence of causation, they can be very useful as starting points for scientific investigation. To go back to my heart attack example, if there were multiple reports of people having heart attacks shortly after taking the medication, doctors and scientists would take those reports seriously, and they would use them as the justification for doing a study. This is a crucially important point: the only way to actually know whether or not the medication causes heart attacks is to compare heart attack rates in people who do and do not take the medicine (or at least compare different doses) while controlling confounding factors. Only then, once you have controlled the confounding factors, can you conclude that the relationship is causal rather than simply being a coincidence. In other words, you have to control all other possibilities and compare two treatment groups before you can conclude that the medicine is the cause. Otherwise, you can never be sure that it’s not just a coincidence.

Now, if we go back to vaccines and autism, we find an identical situation. The fact that many parents have observed autism shortly after a vaccine does not in itself indicate that vaccines cause autism, but it does give scientists something to investigate. In other words, to test those anecdotes and find out whether they are arising from chance or from a causal relationship, we need to compare autism rates among children who did and did not receive a given vaccine. Scientists have, in fact, done that numerous times, which is why anti-vaccers’ comments are a bit strange. I constantly encounter anti-vaccers who insist that scientists aren’t taking parents seriously and haven’t examined the reason that autism often seems to follow vaccines. For example, someone made the following comment on my post about the scientific studies on vaccines and autism.

“In other words, there is a high enough number of parents reporting an immediate and dramatic and permanent change in the behavior of a child, that the link was established. This is the core of what needs to be understood and studied. It also appears that it continues to be ignored. In other words, until we study why these reports exist, and in the numbers that they exist, and focusing on just those particular children, we have not demonstrated the science needed to make a conclusion.”

Notice how the commenter suggests that scientists have ignored parents reports and aren’t studying those reports. That is a rather bizarre accusation given that we have multiple very large studies on whether or not vaccines cause autism. In other words, we know that the anecdotes are wrong because scientists took parents’ concerns seriously, carefully tested vaccines, and repeatedly found that there is no relationship between vaccines and autism. Further, just to be clear, scientists didn’t just do one small study then call it quits. Rather, they have looked it this from multiple angles such as testing different vaccines, examining the effects of age at vaccination, studying children that are at a high risk of autism, testing different doses of vaccines, etc., and some of those tests have been enormous (the largest used over 1.2 million children!). So scientists absolutely took parents’ concerns seriously, but it turned out that the parents’ concerns were unnecessary. In other words, the issue isn’t that scientists are ignoring parents. Rather, the issue is that they didn’t find the results that anti-vaccers wanted them to find. Scientists have very carefully examined vaccines to see if the anecdotes actually represent a causal relationship, and anti-vaccers are simply refusing to accept their results.

See the text for sources and more details.

See the text for sources and more details.

Looking at the math
Despite the fact that anecdotes can’t demonstrate causation and the fact that multiple studies have shown that the anecdotes are in error, many people continue to insist that the temporal relationship between vaccines and autism simply can’t be a result of chance. So let’s look at that with some simple math. What I want to do is calculate how many times we expect the first signs of autism to closely follow vaccines if vaccines don’t actually cause autism.

Note: I will explain the math below, but for your convenience, I have laid it all out in the image above.

According to the CDC, there are roughly 3,988,000 children born in the US each year  (Hamilton et al. 2015). This gives us a nice annual cohort that I want to follow. Over 90% of children in the US receive their full vaccine schedule (Elam-Evans et al. 2014), so that gives us 3,589,200 vaccinated children per annual cohort (0.9*3,988,000). Now, in the US, 1 in 68 children develop autism (Christensen et al. 2016), so if vaccines and autism are not in any way related, we expect that 1 in 68 of our 3,589,200 children will develop autism. Thus, we should have 52,782 children each year who have autism and are fully vaccinated (3,589,200/68).

In roughly 80% of cases, parents first notice the signs of autism prior to a child’s second birthday, and usually not until after around 6 months old (Giacomo and Fombonne 1998). Therefore, for our 52,782 children, there should be 42,226 for which parents first noticed the signs of autism between 6 and 24 months old (0.8*52,782). Now, let’s assume for a minute that there is an equal probability of the first signs of autism appearing on any day during that period (I’ll talk about that assumption in a minute). As a result, we expect 77 children to show the first signs of autism on any given day (42,226 children/548 days).

Now, let’s bring all the pieces together. According to the recommended CDC vaccination schedule, most children receive vaccines on at least 2 days between age 0.5 and 2 years. So if we use that as a conservative estimate, then each year, we expect 154 children (77 cases*2 days) in the US to show the first signs of autism within 24 hours of being vaccinated just by chance (that number goes up dramatically if you spread the vaccines out over more than 2 days). Similarly, each year 1,079 children should show the first signs within 1 week of receiving a vaccine, and 4,623 should show the first signs within 1 month of receiving a vaccine. In other words, so many children develop autism and so many children are vaccinated, that even though vaccines do not cause autism, we still expect there to be hundreds or even thousands of cases where the signs of autism were first noticed shortly after receiving a vaccine (note again that this is the same situation as my fuel example earlier). So we do, in fact, expect there to be lots of coincidences where the detection of autism just happened to follow vaccination.

To be fair, my calculations obviously include two major assumptions, so let’s talk about those for a second. First, I assumed that vaccination only took place on two days, but that is actually a conservative estimate. If everyone vaccinated over 3 days, for example, then we expect there to be 231 annual cases of autism appearing within 24 hours of a vaccine.

Second, I assumed that the rates of autism detection were constant over the period we were talking about. That assumption is clearly false. In actuality, the detection probability goes up over time, but given that one of the days of vaccination is usually early in our time frame and the other is late, that should largely balance out. Also, realize that right now we are quibbling over the exact numbers that I calculated, rather than my central result. In other words, the exact numbers are almost certainly off, but the central point stands (i.e., we expect there to be lots of cases where, just by chance, autism is detected shortly after a vaccine).

Additionally, we would actually expect the odds of a parent noticing the symptoms of autism to skyrocket shortly after a vaccine is administered. Many parents are very concerned about a vaccine harming their child, and, as a result, they will tend to watch their children very closely after vaccinating them (even if they don’t consciously realize that they are doing so). Thus, they are far more likely to notice an early sign of autism that they might have missed if they hadn’t been watching their children so closely. To give an analogy, after people buy a new car, they often start seeing that model and paint job everywhere, but that model isn’t actually any more abundant than it was before, it’s just that their brains notice it because they are thinking about it (consciously or subconsciously). Even so, you are far more likely to notice an early sign of autism if you are worried about it. So in actuality, my numbers are likely underestimates rather than overestimates.

Finally, you may be thinking, “but those numbers are lower than actual number of cases of autism that follow vaccination each year,” to which I have several replies. First, again realize that these numbers are not precise and the true values are likely much higher. Second, where are your sources that the rates are much higher? I’m betting that your sources are simply collections of anecdotes, in which case, you don’t actually have any idea how often autism is detected within a few days of being vaccinated. It may seem much higher than it really is simply because you’re getting your information from internet echo chambers. This brings me to my final and most important point. I completely agree that this argument does not prove that vaccines don’t cause autism. Rather, it simply shows that we expect there to be lots of cases where the detection of autism follows vaccination just be chance. The only way to actually know whether the true rates are higher than the rates expected just by chance is (you guessed it) to do a large study, which, once again, is exactly what scientists have done multiple times.

Note: please read this post before arguing that we need a fully vaccinated vs. full unvaccinated study.

But aren’t autism rates increasing?
As I wrote this post, I could already hear peoples’ keyboards furiously clicking away and arguing that I must be wrong because autism rates have increased over time. So let’s talk about that for a minute. First, as I explained here, at least a large portion of the increase has been due to diagnostic changes, rather than an actual increase (i.e., people who would not have been considered autistic 20 years ago are considered autistic today;  Rutter 2005; Taylor 2006; Bishop et al. 2008; Baxter et al. 2015; Hansen et al. 2015). Second, that doesn’t change the math nor does it refute the numerous large studies that failed to find any evidence of vaccines causing autism. Remember, correlation is not the same as causation. Even if actual autism rates truly are going up, that wouldn’t mean that vaccines are the cause, and in fact, we know that vaccines aren’t the cause because we have so thoroughly studied this.

Summary
In conclusion, anecdotes cannot demonstrate causation, but they can be useful as starting points for further research. In the case of vaccines and autism, that research has been thoroughly conducted, and it has overwhelmingly shown that vaccines do not cause autism. Therefore, the reports of autism being detected shortly after vaccination must be arising by chance. Although many people protest that notion, it is not at all surprising given the number of children who receive vaccines and the number who develop autism. Further, I have mathematically demonstrated that even if vaccines do not cause autism, we expect there to be a large number of cases where, just by chance, autism is detected shortly after the administration of a vaccine.

Related Posts

Literature Cited

  • Baxter et al. 2015. The epidemiology and global burden of autism spectrum disorders. Psychological Medicine 45:601–613.
  • Bishop et al. 2008. Autism and diagnostic substitution: evidence from a study of adults with a history of developmental language disorder. Dev Med Child Neurol 50: 341–345.
  • Christensen et al. 2016. Prevalence and characteristics of autism spectrum disorder among children aged 8 years — autism and developmental disabilities monitoring network, 11 sites, United States, 2012. CDC Morbidity and Mortality Weekly Report 65:1–23.
  • Elam-Evans et al. 2014. National, state, and selected local area vaccination coverage among children aged 19–35 months — United States, 2013. CDC Morbidity and Mortality Weekly Report 63:741–478.
  • Giacomo and Fombonne 1998. Parental recognition of developmental abnormalities in autism. European Child and Adolescent Psychiatry 7:131–136.
  • Hamilton et al. 2015. Births: Final Data for 2014. National Vital Statistics Reports. CDC.
  • Hansen et al. 2015. Explaining the increase in the prevalence of autism spectrum disorders: the proportion attributable to changes in reporting practices. JAMA Pediatrics 169:56–62.
  • Rutter. 2005. Incidence of autism spectrum disorders: changes over time and their meaning. Acta Paediatr 94:2–15
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