Answers in Genesis recently published two studies by Dr Jeanson in their scientific journal. Both focus on how evolution since Noah and his ark. Both are titled “On the Origin. . . “. And the results of both – they claim – support the creationist point of view.
The first investigated whether evolution could have happened rapidly enough to explain the emergence of all the species since Noah. This revealed it couldn’t; a fact which was explained away with miracles. The second paper is what interests me today. It focuses on humans and whether the diversity present in our species is consistent with the Noah story.
This research has two main conclusions. The first is that all humans’ mtDNA fall into three groups. This matches Noah’s three children – each of whom is thought to have been the ancestor of one group of people (explaining why non-whites should be slaves). The second conclusion is that the number of mutations present in our mtDNA is consistent with the Biblical timeline.
Both of these conclusions would seem to be fairly major victories for the creationists. And several creationist organisations are already touting them as such. The problem is that they’re based on bad science. And yet this all got through creationist peer review.
Unrooting a tree
The first major contention of Dr Jeanson’s latest paper on Noah is that our mtDNA is consistent with the Biblical narrative. This was calculated simply enough; by drawing a family tree of 369 humans’ mtDNA.
The resulting tree has three major groups. Noah brought his three kids (and their wives) onto the ark. Under the creationist narrative, each is thought to have given rise to one branch of humanity. Thus the presence of three groups – matching this story – would vindicate the creationist model.
Already things are starting to go wrong for Dr Jeanson as he doesn’t seem to have done anything to vindicate this conclusion. There’s no statistics demonstrating that the mtDNA he’s studying falls into these clusters. He seems to just be eye-balling it from the tree. “Eh, it looks like there’s three significant nodes”. Hardly the most reliable methodology for vindicating genesis.
Now, some of you might have noticed this tree doesn’t look exactly like the traditional family tree you might be familiar with. This is because it’s unrooted. To “root” it you have to add in a branch that isn’t part of the group you’re studying (so for humans, the outgroup might be chimps). This puts the entire tree in context and allows you to construct the rooted family tree you’re more familiar with.
This is where the first major problem with Dr Jeanson’s paper is: you need to root a tree to study ancestry. An unrooted tree simply tells you how similar the individuals in it are. It can’t tell you what they’re ancestry was; who descended from whom and so forth. For instance, under the unrooted ape tree all of the apes could have evolved from humans. There’s no information about the direction of evolution in an unrooted tree. Or for Dr Jeanson’s tree, one group of women could have given rise to the other two; rather than all three co-existing as Noah’s wives.
Yet Dr Jeanson is trying to study human ancestry and whether it matches with the three wives of Noah. That’s something that can’t be done from this tree. At best he could say humans fall into three similar clusters. Except as his chart shows, there’s more than three clusters involved (with no statistics to narrow it down to three).
What’s more, I’m really curious as to whether or not it would be even possible for a creationist to vindicate the Noah story using this method. After all, you need an outgroup. A distantly related population to put your tree in context. Yet they claim humans are unique, distinct from the rest of the world. Is there even an outgroup for them to compare this data to?
So not only does this not show what Dr Jeanson thinks it shows, it’s impossible for it to do so.
Mutations since Noah
Basing conclusions on the wrong type of chart seems bad. To make matters worse, it’s a chart that can’t support your conclusions at all. However, things go off the rails even more when it comes to Dr Jeanson’s second hypothesis.
This is the claim that the number of mutations in human mtDNA is more consistent with the Biblical narrative than the evolutionary one. This was calculated by examining the number of differences between our mtDNA. The number of mutations per generation was then used to figure out how many generations were needed to produce this number of differences. This was then calculated into years by using UN data from Africa (in the 70s) on how long generations are.
It turns out that if humans have been reproducing like Africans from the 1970s then the number of differences between individuals is consistent with the flood timeline. Unlike the evolutionary estimates.
But before you give all your money (or your house) to Answers in Genesis, we need to dig a little deeper. It turns out that the diversity present in a genome isn’t just the result of time x mutations as Dr Jeanson would have you believe. Several other factors are involved.
One of the biggest being evolution. Kind of ironic, isn’t it? For example, think about what would happen if one of these mutations was harmful to the mtDNA. The individual with it wouldn’t survive as well, eventually being out-competed (and that mutation lost). So you might expect a lineage to have accumulated 10 differences from another, based on the rate of mutation. But in reality the actual number might be much lower if some of those changes were harmful and purged from the genome. A similar effect would happen if the mutation was beneficial. It would outcompete others, driving them extinct and reducing the overall diversity in a population.
Another big factor is population size. The general idea is that the more reproduction that goes on in a population, the more mutations will be passed on to each subsequent generation. A larger population can also “store” more diversity. For example, using Jeanson’s numbers, if you were to compare the mtDNA of me and Bob, there would be 123 differences between us. And if you compared Bob and Sally, there would be 123 differences between them. The key issue is that they could be different differences. There might be a separate set of 123 differences between Bob and Sally than there are between Bob and me. This would produce up to 246 mutations separating all of us.
Ultimately there are upwards of 7,000 mutations in human mtDNA; with each person having a maximum of 123 of them. Is this consistent with Dr Jeanson’s predictions? That all depends on how big the population was. Different sized populations (with different levels of reproduction) would take different lengths of time to accumulate the 7,000 mutations and the resulting 123 differences between people. Now, to be fair to Dr Jeanson, there is some debate over how big a role population size plays in genome diversity, with there being some evidence for it and some evidence against it. Ultimately, it seems like it does play a role but a relatively small one. Nevertheless, that’s a factor that should be investigated yet another factor ignored by the creationist.
And those aren’t the only two factors involved. There are countless others. All of this mean there’s often relatively little correlation between the raw rate of mutation and the resulting diversity in the population. For example (in the nuclear DNA), flies and humans have a similar mutation rate. But the resulting diversity in our genomes differs by an order of magnitude. Yet the entire conclusion of this paper relies on their being a link between these two values.
Or – in simpler terms – the creationist model is nonsense. And this paper is too.
A creationist claim DNA supports the Noah story, but it only does so because he uses the wrong figures and data to support his conclusions.