Genetics and human life spans in Genesis

In Joshua Swamidass book Genealogical Adam and Eve: The Surprising Science of Universal Ancestry he writes:

“Each part of the genome has a different genetic common ancestor, and the full set of data must be examined to understand when and where a genetic progenitor couple did or did not arise. Looking at all the data, if there are no people outside the Garden, Adam and Eve seem solidly ruled out by the data more recently than five hundred thousand years ago.”

This is just a thought experiment: According to Genesis people were once living until almost 1000 years old. If we assume for sake of argument the creationist 6,000 year timeline, then these long lifespans would mean there were even fewer generation between the modern day and Adam and Eve. However it would also mean that one individual male could have hundreds of kids during his lifetime (especially if we assume he had more than one wife), which would mean that one individual male would die having added more variation to the pool then someone alive today who lives only 70/80 years who who only had 2 kids? And what effect would this have on the 500,000 year figure mentioned in the quote above?

There’s an important point that just about everybody seems to miss when discussing the long lifespans in Genesis, both YECs and those who respond to them.

Nowhere in Genesis does it say, or even imply, that most people lived that long.

The only people who are described as having had long lives spanning hundreds of years are the people in the direct line from Adam to Noah via Seth. We aren’t given the ages for anyone in Cain’s line. In fact, throughout Genesis chapter 4, which focuses on Cain’s descendants, the theme that occurs throughout the chapter is death, in some cases by violent means.

This suggests to me that the point of the long lifespans was a theological one rather than a literal one, drawing a contrast between the way of death (apart from God) and the way of life (walking with God). But even if they were intended to be read literally, I get the impression that they were intended to be viewed as the exception rather than the rule.


Those old guys would continually contribute the same alleles to their offspring. That would lead to more, not less, inbreeding.


Right of course. So pointing to the large number of offspring that individuals could produce during a 1,000 year life span, wouldn’t help a creationist to get the 500,000 year figure down?

So there simply is no way to harmonise the genetic diversity in the modern day human population with the idea that all humanity descends from a single progenitor couple (with nobody else alive at the time) inside the last 500,000 years, let alone 6,000 years?

Well, no reasonable or credible way. But the creationists do have a way: created diversity. It happens that Adam’s sperm and Eve’s eggs were created with all sorts of variation not present in their somatic cells: a whole diverse population in their naughty bits, just waiting to make lots of different zygotes.


Right…. okay…… that’s stretching it a bit :joy:. So Adam and Eve had all the variation for all future humans present in there gametes. So they had gametes unlike anyone alive today. Why would god even need to do that? As you said, not reasonable or credible, but very ad hoc.

I suspect it’s not even biologically possible, and if it is, then it would be something really strange and unrecognizable. It doesn’t seem worth the effort to speculate, much less argue with those suggesting such things.


That’s what sh… never mind.


I don’t think it’s work for Adam’s sperm – as that would have been continuously being replenished (using Adam’s DNA, unless a really complicated ongoing miracle were assumed).

I think it might be possible for Eve, given that a female’s eggs don’t replenish (that is correct isn’t it?), so God could have created her with every egg having different DNA.

I must have a twisted mind – because I find such absurd speculations to be a heap of fun. :smiley:


All you need is a bunch of different original cell lines in Adam’s testes. Each of those cell lines would keep producing sperm of separate genotypes.

Even if this was credible, which it’s not, why would god bother doing this? I just can’t see a reason why, even if we assume creationism just for sake of argument, why he would do this. The only reason it’s even suggested is because creationists are trying to come up with an ad hoc excuse for the evidence not matching up

Wouldn’t having all these different cell lines be problematic due to things like autoimmune responses, etc?

You must understand that, since he was created as an adult, Adam’s immune system would have been made so as to accommodate all his cell lines.

Mysterious ways? Were you there? Etc.

Well, yeah, you can explain anything away like that though. The only reason I can see for why creationists would even suggest that this is plausible is if they don’t like the evidence

I think we are all guilty of that from time to time :sweat_smile:

IMO this is a form of the Omphalos Argument - God can do anything and make it look like anything else, may have done so last Thursday, and no one can prove otherwise.

This is just bad theology. Whatever beliefs they held before making this argument are now compromised, because they just admitted their version of God might be lying. It’s a great point to stop arguing with that person too - they have just lost the argument even if they won’t admit it.


Sure. They’re cutting their ideas to fit. But if God actually had created a single pair of humans, there is a potentially rational reason for making them extra diverse, i.e. avoiding extinction from inbreeding depression. Mind you, the simpler way to do what would be to create a diverse initial population of actual organisms. But mysterious ways, you know.

If we take that idea seriously (:joy:) just for arguments sake: Then wouldn’t this single pair need to pass on all/most of that extra diversity to their offspring otherwise in the next generation the they’d quickly run into the inbreeding problem again due to a lack of diversity? If Adam and Eve had all this “extra diversity” but still only passed on one allele each to their offspring, the inbreeding problem still exits. On the other hand if they did pass on all this “extra diversity” how come individuals today don’t still have this “extra diversity”?

Yes, but they could parcel it out. No single offspring would have to be unusually diverse as long as the whole collection of them was. Recall that Adam and Eve supposedly lived for hundreds of years and had many children, conceivably hundreds. Each child would be radically different, genetically, and the resulting population would reflect the diversity of the first couple’s gametes, thus escaping the genetic bottleneck.