Testing the creationist hypothesis

I’m not a creationists but I’m trying to imagine what the genetic data should look like if they were right. For example, the typical young earth creationists hypothesis is that humans are a special creation just 6,000 years ago with no other humans outside the garden of Eden. They also claim that people were living until 1,000 years old for the first 2,500 years. This would mean that each individual would have far more offspring then today.

Joshua Swamidass and William Lane Craig have both written books explaining that the genetic evidence shows that the human population has never been as low as 2 in the last 500,000 yrs (before then it’s a bit more difficult to say). But if we were to assume (for sake or argument) the YEC hypothesis that people lived much longer in the past and had more offspring (although even if one male had 1000 children they would all be pretty much identical genetically) would it change anything with regards to the to the data? :thinking:

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the creationist model is made further preposterous by claiming a bottleneck of 8 humans 4350 years ago after a genocidal global flood by a tyrannical God. Take a look at the new genetic tree going back 2 million years and compare.

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It would make no sense, which is why creationists neither advance nor test creationist hypotheses.


Yes that as well. I’m just wondering what the genetic data would look like if there really were people living until 1000 years old between 6,000 and 2,000 BC. Their hypothesis of a only one single couple on the whole earth from whom we all descend can’t possibly work as the data suggests that the human population has never been that low in the last 500,000 years. But I’m assuming that data is based on humans living to the ages they do today (around 80), so if we assume the YEC hypothesis with longer lifespans and each individual having far more offspring than today, would that being the 500,000 years figure down.

This would also have the consequence that the male germline mutation rate would be even more different from the female mutation rate than we observe, since spermatogenesis is a continuous process while oogenesis is finished in the fetus.


The simple answer is the genetic data shouldn’t look like evolution. That is, we shouldn’t see a nested hierarchy, specific patterns of divergence, and specific patterns of substitution bias (i.e. transitions favored over transversions).

For example, why a nested hierarchy? There’s no reason to expect one if kinds or species were separately created. A designer could mix and match genes from numerous other kinds, all without worrying about changing the sequence so that we get a nested hierarchy. In fact, this is exactly how humans design organisms. We often take a gene from one species and put it into a very distantly related organism without changing the sequence hardly at all.


Yeah definitely. I mean specifically with regards to the data that shows that the human population never dipped as low as 2 in the last 500,000 years.

Joshua Swamidass says on his book that:

“Looking at all the data, if there are no people outside the Garden [of Eden], Adam and Eve seem solidly ruled out by the data more recently than five hundred thousand years ago.”

If we built in the creationist assumption (just for sake testing the hypothesis, I do NOT agree with YEC) that people lived much longer in the past (c. 1000 years old) and therefore had far more offspring (I guess they say each male had hundreds of children if they lived until 1000), would the 500,000 years figure change? My point is they there’s no point using this data to refute young earth creationist claims if I’m making a straw man argument.

Longer lifespans would only reduce the number of generations, worsening the problem for the theory of a single ancestral couple. If my understanding of population genetics is correct, the number of offspring would also not help because it is the number of generations that results in accumulated divergence, not the number of offspring.

What you are describing is a population bottleneck followed by a rapid population boom. There are species out there that have gone through this type of bottleneck, such as cheetahs. The rapid population boom doesn’t increase the genetic diversity of the population. That takes more time, not more offspring.


Not specifically what you’re looking for, but here are two failed creationist hypotheses:

  1. Jeanson’s mitochondrial DNA mutation rate can be tested against known divergence time, such as the original settlement of the Canary Islands from North Africa. We have mitochondrial sequences from both populations and a fairly concrete timeframe for their divergence. When we document the actual number of differences (2-3) compared to what Jeanson’s rate would imply, we find Jeanson’s rate is far too high.

  2. If the creationist “orchard of life” is correct, we can expect nested hierarchies on constrained sequences for all cellular life, but we should only see nested hierarchies for unconstrained sequences within each “kind” and no correlation “between kinds”. We actually see strong correlations on constrained and unconstrained sequences, which invalidates the separate ancestry hypothesis.


Ah yes of course. So on the YEC view where people lived until almost 1,000 (I’m trying to say that with a straight face) there would’ve been fewer generations between 4,000 BC and today than if we assume the lifespans were as they are today.

You mean because even if one man had 500 kids (still trying to keep a straight face) they would all be pretty much identical genetically, so there still wouldn’t be a lot of variation.

True for genes passing through women but not for genes passing through men.

No, they wouldn’t be identical, but they would only provide a very small pool of variation (aka polymorphism).

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I don’t see why. You might as well get a star phylogeny, or a number of huge polytomies. And worse we can have no expectation of consilience between trees derived from different sequences. Why should the tree from a ribosomal protein have a highly similar topology to one derived from some other completely unrelated sequece, such as aa-tRNA-synthetase, or the SecY transporter, or subunits from ATP-synthase?

There simply is no other good explanation for this result than common descent, or a deceptive God that wants to make life look like it is all genalogically and genetically related.

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There’s probably a really obvious answer to this and I’m probably gonna kick myself for even asking this, but why would there be fewer generations of women on the creationist hypothesis than men? If men were also living to 1,000 in the past then wouldn’t there be fewer generations of both male and female?

Why would that be?

Yeah, that’s what I meant. The genetic variation would be minimal (thought not identical), therefore it wouldn’t help the creationist argument at all

There would not, though the bible is strangely silent on how long women lived. But the point is that spermatogenesis goes on throughout a man’s life, so the older the man, the more mutations in the germ line. Women, however, have all the eggs they’re going to have at birth.

NOTE: Population genetics isn’t my specialty, so everything I say comes with the caveat “As I understand it with an imperfect grasp of pop gen”.

The analogy that comes to my mind is the game of telephone. This is where you whisper a simple sentence to one person, and they pass on the message to the next person, and repeat. As you move further from the source the more the message changes. If the game started by one person telling 100 people the message then there would only be small changes to the message among those 100 people. It is the iterative process of passing the message to the next person that produces cumulative change.


Because creationists accept evolution inside a “kind”, so there is still a branching pattern but only inside the kind. So for example they think all dog species evolved from an ancestral “dog” common ancestor, so there would be nested hierarchical patterns showing how these dog species diverged from the common ancestor.

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Not sure what that has to do with the original claim. I take “constrained sequences” to be those under selection, and they are supposed to display a nested hierarchy throughout all cellular life, not just within dogs.

But if the quite different idea you present is true, that’s great news for creationists, because we can now identify “kinds” easily: they end at the point at which nested hierarchy stops. Sadly, nobody can find such a point.

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