@Jon_Garvey I saw your post on this on your blog: http://potiphar.jongarvey.co.uk/2018/03/21/do-not-touch-my-anointed/
The irony here is thick. Both you and @Chris_Falter agree with the overall conclusions that a recent sole-genetic progenitor is not likely. It seems you both agree with the conclusions I’ve drawn from the data. However the debate continues in an unclear way about our epistemological certainty about this.
I think there is some confusion about how science reasoning works in conjunction with modeling in this area.
The way I see the situation, is that there is data we have collected about human variation. There is, at this time, a wide range of models proposed to account for that data. However, there is not a single model proposed that can account for the data with a single couple origin less than 200 kya, without either (1) inferring ongoing miracles, (2) totally different biology for Adam and Eve (e.g. genetic mosaics), or (3) mutation rates an order of magnitude (or more) higher than we have ever observed in humans.
That is why, based on our current knowledge, we are calling this evidence against a recent bottleneck. Until a model with a shorter time frame is put forward and tested, this is what we think the data is showing us. For those that disagree, they are welcome to put forward a model of their own to test, but failing that there is not really much to dispute.
Generically calling the conclusions into question is not helpful. The best way to unseat the conclusions is to produce a model that accounts for the data in a shorter time span.
However, I think I understand @Jon_Garvey’s motivation. We do not want to state these claims with too much certainty, as we have just seen a large shift in our understanding here. I’d point, again, to my invitational epistemology as a solution to this paradox. I’ve already pointed out three ways a more recent bottleneck might be possible:
- Adam and Eve had totally different biology than us (e.g. genetic mosaics)
- Ongoing miracles that diversify us more than is possible by natural processes alone.
- Much higher mutation rates in the distant past than we can imagine or observe in humans (perhaps miraculously?)
All these options require deus ex machina miracles, not attested to in Scripture. So we do not consider them in scientific analysis, even if they could be true. We do however invite all who dispute these findings to propose models of their own to make sense of that data. Until a model is produced that can made sense of the data with a recent bottleneck and no miracles, we are justified in saying: the data just looks like we do not have a single couple bottleneck before about 500 kya.
That is the plain reading of human genomes.
Others can dispute those findings, but they better come with a plausible and alternate model with at least as much mathematical rigour as we have done here. Generically casting doubt on the whole exercise does not move us forward. That is not how our understanding progresses.