Most YECs adhere to a model which has the origin of the biosphere at about 6,500 years ago, with a world wide flood at about 4,500 ya. Important to this topic is that, in this model, humans descend from an original pair at 6,500 ya, and go through a flood bottleneck with an effective size of 6 people (Noah's three sons and their wives) at 4,500 ya.
I will show that modern humans have far too much genetic diversity for this model to be correct. We will look at Y-chromosome diversity and mitochondrial diversity amongst other things, and compare what is known about mutation rates to the proposed time scale.
In addition, we can look at other animals which would have required the Ark to survive the flood, and therefore should also show the symptoms of recent tight bottlenecking in their genomes.
Participants, please be prepared to read a few interesting contemporary research papers which I'll bring up in the first few posts.
For a start, here's a thirteen generation pedigree study which gives us some idea of the human Y-chromosome base substitution rate.
Human Y Chromosome Base-Substitution Mutation Rate Measured by Direct Sequencing
And this should give you some idea of modern diversity on the Y-chromosome.
A calibrated human Y-chromosomal phylogeny based on resequencing
The first paper gives us a point mutation rate of 4 in 13 generations, or approximately 1 for every three generations, on the non-recombining area of the Y-chromosome (which is ~95% of it). The Y-chromosome is inherited from father to son, so, in the young earth scenario, we all have the Y-chromosome of Noah, with the only difference being the mutations that have occured since. The one in three substitution rate puts us all about 60 mutations away from Noah, as 4,500 years equals about 180 generations. Therefore, modern men should only differ by a maximum of about 120 (Y-chromosome) point mutations from each other (the maximum would be found in individuals who do not share a common male ancestor since Noah).
The second paper searches areas of the Y-chromosome that comprise about one fifth of its total in 36 individuals, and comes out with far too many variations to fit the "Noah" scenario (and far too many to fit the 6,500 year Adam scenario). There's so much difference that this alone can be regarded as a reasonable falsification of the YEC model on its own. From the figures in this paper we can infer an average difference between individuals in the group of 36 to be over 1600 across the whole Y-chromosome. This is clearly incompatible with the maximum ~120 that the standard YEC model predicts.
Mods: Biological Evolution please.
Edited by bluegenes, : took out extra word
Edited by bluegenes, : Added explanation of links at Admin's request.
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