Adam and Eve possible?: Ayala’s contrary claim built in favourable assumptions
|June 20, 2012||Posted by News under Human evolution, Intelligent Design|
We are not going to make it easy for anyone to just not buy the book, Science and Human Origins, by Ann Gauger, Doug Axe, and Casey Luskin. And read for themselves why Ann Gauger thinks that Francisco Ayala is wrong in saying that the human race could not have had two first parents.
Before they hold forth.
But here are a couple of paragraphs:
The Challenge to the Challenge
Let’s step back and examine how Ayala’s analysis was done. His claims against a literal Adam and Eve are based on population genetics models for how gene frequencies change in populations over time, and how ancestral gene lineages tend to coalesce. The equations used to reconstruct these trees, and to calculate ancestral population sizes, depend on simplifications and assumptions to make the mathematics tractable, as I said before. These explicit assumptions include a constant background mutation rate over time, lack of selection for genetic change on
the DNA sequences being studied, random breeding among individuals, no migrations in or out of the breeding population, and a constant population size . If any of these assumptions turn out to be unrealistic, the results of a model may be seriously flawed.
There are also hidden assumptions buried in population genetics models, assumptions that rely upon the very thing they are meant to demonstrate. For example, tree-drawing algorithms assume that a tree of common descent exists. The population genetics equations also assume that random processes are the only causes of genetic change over time, an assumption drawn from naturalism. What if non-natural causes, or even unknown natural causes that do not act randomly, have intervened to produce genetic change?
It turns out that the particular DNA sequence from HLA-DRB1 that Ayala used in his analysis was guaranteed to give an overestimate, because he inadequately controlled for two of the above assumptions—the assumption that there is a lack of selection for genetic change on the DNA sequence being studied, and the assumption of a constant background mutation rate over time. (Pp. 111-12)
See also: Breaking: Adam and Eve are scientifically possible
Also: New excerpt: here.