I guess they could say it was parcelled out. Although they also think there was a bottleneck of 8 at the time of the flood. 3 of those 8 were the children of Noah and his wife, so I guess in that case all the variation would’ve had to come from just 5 people. Sure, it’s more than 2 like in the case of Adam and Eve, but wouldn’t creationists have the same problem trying to explain a 5 person bottleneck as they would a founding couple who were supposedly the progenitors of all humans who ever lived, except with the flood bottleneck they couldn’t claim they had “extra diversity”?
2 Likes
Yes, that’s a whole nother problem.
2 Likes
It seems to me that much created heterzygosity would be lost to those who did not make it on board the ark, but I’m no population geneticist. Here is Sanford, Carter, et al. Adam and Eve, Designed Diversity, and Allele Frequencies, on this issue.
Some fraction of the pre-Flood genetic diversity would be lost due to the genetic bottleneck of the biblical Flood. However, population geneticists have known for decades that even the most extreme bottleneck (i.e., two people) can capture a significant amount of a population’s pre-bottleneck diversity, assuming the bottleneck only lasts for one or just a few generations and is followed by rapid population re-growth (Nei et al. 1975). This has also been demonstrated using computer simulations of a single-generation Flood-type bottleneck involving just three founding couples (Carter and Powell 2016). Therefore, there is no problem with the Flood scenario in terms of preserving most of the originally designed variants, even though there would be some loss of diversity. For example, if Noah’s three daughters-in-law were distantly related, the Ark-borne population could have carried up to 80% of the pre-Flood diversity (Carter and Powell 2016). Even in a worst-case scenario (where Shem, Ham and Japheth married their sisters), nearly 60% of the pre-Flood diversity would still have been retained (Carter 2018). Thus, while some created diversity would be lost at the Flood, Noah’s family could have easily carried millions of polymorphic alleles.
Expanding this single gene example across the entire genome reveals a tremendous potential for allelic diversity on the Ark. In just two diploid individuals, four genome copies exist. Since only four DNA base-pairs exist, virtually every possible genomic position allele (i.e., far more than 4–28 gene unit alleles) could have been present at the time of the Flood, if the individuals were heterozygous.
Note the elided difference between “a significant amount” and “most” in successive sentences.
And Jeanson’s scenario assumes both an unrealistic degree of heterozygosity and an unreasonable amount of subsequent recombination and, oddly enough, loss of most recombined alleles.
3 Likes
This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.