PS @swamidass if it is possible to do so I triple-dog dare you to run the test in a way that would catch a genetic signature from a recent de-novo Adam.
If I were you, I’d offer free shipping of all those dogs as a further inducement. Josh has a small, but good one already.
If I somewhat understand what he is saying he will test, I don’t think it would pick up a de-novo Adam anyway. At least not as a recent de-novo Adam. It would just give an estimate on how long it would take whatever is found in the Adam signature to have evolved from a common human ancestor.
And that is the ironic rub. A recent de-novo Adam could itself contribute to an appearance of an earlier date for a sole-genetic progenitor Adam for human-specific alleles. This would be the case if his gene aleeles were novel in these places. Either way you would get to the need for an earlier population outside the garden. Either because the numbers really do show a bottleneck of two would have to be in the distant past or the presence of a de-novo Adam would make it seem that way.
They actually discussed that as a possible source of error.
It didn’t amount to anything unless god intervened with a miracle to make the chromosomes “doubled or tripled” and replicating vast complexities. It was considered an “over the top” concern.
The best they could do was conclude: If there was a 2-person bottleneck on the other side of 700,000 years… nobody would be able to prove there wasn’t because at 700,000 years ago… there’s too much noise to notice a 2 person bottleneck.
First of all… there’s a definitional thing.
If you have de novo Adam & Eve at any time when there are 10,000 other humans… that’s not detectable at all… assuming the de novo creations have human-compatible genetics.
Mark, you’re not looking for a two person bottleneck anyway, are you? Help me understand, if so.
If I understand Mark’s position, @Guy_Coe, he COULD have a 2 person de novo creation when it comes time to specially create humans.
But he has to put them behind the 700,000 year wall … because any more recent than that and it would be detectable… which it isn’t.
I am not. I am just saying that it is still possible for Adam and Eve to have a detectable genetic signature. Science could not say it was them, but there would be something there consistent with that. They are not necessarily genetic ghosts.
A recent de novo Adam and Eve would be a bottleneck… for what, exactly? Mark, if I understand him correctly, “prefers” about a 13 kya date. The closest thing to a bottleneck would be after the flood, in my understanding of him.
No sir. I am saying it could be detectable under a scenario where the human race chugs along for 150,000 years with low numbers and then Adam and Eve are formed right before the population starts increasing.
The reality of the current state of diverse genetics in the human genome, your first 2 humans have to be further back than 700,000 years.
You have to contrive really crazy mixed up genetics to explain why the current population is so diverse in the present day.
Thanks for clarifying, Mark. And thanks, George.
It would not be a “bottleneck”. I am just saying that this scenario could produce a signal in the genetic noise.
You could use a box of crayons… or leggos (sp?) to demo that… and the demo wouldn’t run like you think it would. You have to have a “source” of diversity…LOTS of diversity.
That requires sheer numbers in the population… so if you want to have fewer years of mutations… then you have to have a MASSIVE population for longer than expected… not a SMALLER population.
They’ve done estimates of world populations for the last 5000 years… and they’ve projected back from there…
this would be like trying to hide 600,000 men in the Sinai Exodus… it’s hard to hide those kind of numbers!.. since you would need to have MILLIONS of extra humans to generate the alleles we have today.
How about an initial population of 10,000 which already had some genetic diversity to start with?
Listen to @gbrooks9 on that. He is right, and not even frantic! There is no way to detect a recent Genealogical Adam.
You can, nonetheless, detect several things that are coherent with a recent GA. We covered some of them in the past on this blog.
Well… there’s a limit to how much diversity it can have … because 10,000 is 5,000 pairs… or 5000 x 46 chromsomes… that’s all the carrying capacity.
You need a big population going on for thousands of years… BEFORE you even arrive at the Sumerian civilization.
This is what I mean- looking for signals which are consistent with the idea of a recent GA. Even that may not be possible - for example if his gene structure was virtually the same as those around him. Not that we can prove it was from Adam anyway, but a signal consistent with the hypothesis. I mean, they have demonstrated to most people’s satisfaction that alleles from 55,000 years ago are from Neanderthals, but we had the advantage of a Neanderthal genome to compare it to. Without the DNA from Adam’s ear bone or something, we can’t go that far.
Looking at the spread of civilization is a good strategy. For that, I highly recommend David Reich’s book, as would @Patrick. If you haven’t bought it yet, click the link here and get it. It will give me a buck of affiliate income too =).
To be current on the science of ancient DNA, you really have to read David Reich’s book. New results are coming out nearly monthly. There are many surprises coming that will “change everything in what you thought you knew”. Realize that the general public is becoming aware of the findings of ancient DNA, so you need to stay as current as possible of the latest findings. I am trying to help you in this regard by posting the latest science I can get my hands on.
Another very good book is Adam Rutherford’s “A Brief History of Everyone Who Ever Lived”
Remember that first and foremost you mustn’t allow your flight of fancy (sorry, your theological musings) be contrary to the latest finding in the science of human origins, or you will be accused of being pseudoscience creationists. The science is moving rapidly and is messy and can overturn last years results as more data is analyzed. RTB, for example, should get prepared for monthly updates to their model.