THE MYTH OF THE “MYTH” OF ADAM AND EVE
Dennis Bonnette
"More daunting are the claims made by some molecular biologists against Adam and Eve’s possibility. Using a schema of common descent, some leading geneticists have claimed that, since the time – at least seven million years ago – that the lineages leading to chimpanzees diverged from those leading to modern human beings, there never has been a bottleneck (reduced population) of a single mating pair of hominins: no Adam and Eve.
The following comments upon genetics are based largely upon an examination of the recent scientific literature. Using current human genetic diversity, some researchers estimate that the “effective population size” (an idealized size of a breeding population) of the hominin population has never been smaller than one thousand in the last two million years, thereby, excluding the possibility of a single mating pair during that time. Still, these sorts of estimates are based on mathematical models, which depend upon many assumptions about stability of population dynamics, mutation rate, and so on. These assumptions are unlikely to represent real populations. Such difficulties have led other geneticists to infer that DNA sequence differences alone may not be sufficient to determine effective population size.
The most significant genetic objection against an historical Adam and Eve is the claim that, for some genes, there simply were too many ancient alleles, too many ancestral lineages, to have passed through a single mating pair of first true humans. In 1995, a study by geneticist Francisco J. Ayala, entitled, “The Myth of Eve: Molecular Biology and Human Origins,” epitomizes this objection, yet also reveals the inherent vulnerabilities of such claims. Ayala studied the highly polymorphic HLA-DRB1 gene, concluding that at the time of the Homo (human)/Pan (chimpanzee) split there must have been thirty-two separate versions of this gene present in the founding population. Since a single mating pair can pass through only four versions, he inferred that a bottleneck of two individuals as founders was not possible then or any time since. In fact, he insisted that the minimum number of individuals in the population could never have been less than four thousand.
However, Ayala based his claim on a very small portion of the gene, the portion where nearly all the polymorphism occurs. A later 1998 study headed by Tomas Bergström pointed out that using that portion violated the assumptions necessary for the estimate to be reliable. Using a portion of the gene not susceptible to frequent mutations, his group came to a very different conclusion, namely, that only seven ancient lineages of the HLA-DRB1 gene existed at the time of the Homo/Pan split. And in 2007, another study from Bergström’s group concluded that only four allelic lineages predate five million years ago, with a few more being present shortly after that time. Just two mating hominins could pass on four lineages; the appearance of several more lineages shortly after five million years ago remains unexplained.
We cannot conclude from these studies anything definitive about human origins. Nonetheless, it is truly astonishing how far downward these studies have come in their conclusions about the number of ancient HLA-DRB1 gene lineages – from thirty-two to seven to just four – underlining the tentativeness of scientific studies in this critical area of molecular biology. This progressive weakening of scientific claims is hardly supportive of dogmatic assertions of the “impossibility” of a single set of first parents, Adam and Eve. Unfortunately, Ayala’s unwarranted claims have strongly influenced public discussion of a literal Adam and Eve, while the later studies are largely unknown."
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Our Fragile Intellect **
Trends in Genetics references this paper -
Our Fragile Intellect.(download) What is interesting about this is that we peaked 2000-6000 years ago and now are devolving. Or… we started out pristine with the preternatural gifts of bodily immortality and freedom from sickness and have lost it.
Analysis of 6,515 exomes reveals the recent origin of most human protein-coding variants 86% arose in the last 5-10,000 years.
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Past 5,000 years prolific for changes to human genome**
A study published today in
Nature3 now helps to clarify when many of those rare variants arose. Researchers used deep sequencing to locate and date more than one million single-nucleotide variants — locations where a single letter of the DNA sequence is different from other individuals — in the genomes of 6,500 African and European Americans. The findings confirm their earlier work suggesting that the majority of variants, including potentially harmful ones, were picked up during the past 5,000–10,000 years. Researchers also saw the genetic stamp of the diverging migratory history of the two groups.
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Rocking the foundations of biology **
Here it is again - top down - DNA is not the sole transmitter of inheritance - paper after paper is now showing the inheritance epigenetic information - information is the driver.
