Thursday, 4 June 2015

A Christadelphian special creationist gets himself into a bind on the question of Adam and genomics

While the wholesale denial of the fact of human evolution alone is enough to destroy the credibility of the evolution denialists in our community, sometimes it is the abysmal reasoning seen in their arguments that is alone is enough to confirm that they have nothing to contribute to the discussion. This is particularly damning when such examples come from those with a background in philosophy, such as the person behind the soon to be mothballed page "Special Creationism - A Christadelphian Perspective".

In a post from the 22nd May, the author declares:
The special creation of Adam and Eve is the Achilles-heel of theistic evolution/evolutionary creationism. If they deny this, they reject Genesis and drive a coach and horses through the biblical doctrine of sin, death and salvation. If they affirm it, they face the inconsistency of having evolution for the tree of life and all the primates except Adam, Eve and their descendants. They exclude the empirical evidence of common descent from applying to Adam and Eve but without justification. They are in a bind.

"Once the special creation of Adam and Eve is admitted, the only logical harmonisation of the Bible and Science is that of Old Earth Creationism which allows progressive creationism to co-exist with evolution in the natural history of life on earth."
One sees bald assertions, and ignorance of the evidence for human evolution, but nothing approximating a sound argument. Take the claim that the special creation of Adam and Eve is allegedly an Achilees heel for evolutionary creationism. Why? SCACP claims that if we reject this, we reject Genesis and destroy the Biblical doctrine of sin, death, and salvation. Well, we don't reject the special creation of Adam. What we do reject is the mistaken belief that he was the sole ancestor of the entire human race. Adam was not only a special creation, but the first person to whom God revealed himself. Prior to this, the concept of sin was meaningless and pre-Adamic humans lived and died as the beasts that perish. Genesis 1, while not a literal account of creation (clearly shown by its allusion to a pre-scientific cosmogeography in its reference to a solid firmament [1-3], a view denied only by a tiny, irrelevant,  fundamentalist rump of modern scholarship) nonetheless alludes strongly to more than two people in verses 26-28, whereas Gen 2 clearly refers to the creation of two people. In other words, the creation accounts are sequential, rather than concurrent.

SCACP's attempt to trap the evolutionary creationist who accepts the special creation of Adam not only shows a remarkable ignorance of the genomic evidence for human evolution and against monogenism, the belief that the entire human race descended exclusively from two people, but some appalling reasoning::

"If they affirm it, they face the inconsistency of having evolution for the tree of life and all the primates except Adam, Eve and their descendants. They exclude the empirical evidence of common descent from applying to Adam and Eve but without justification. They are in a bind."
Again, no justification is given for this remarkable statement. It is pure assertion. Once again, the evidence for human-ape common ancestry is overwhelming, with the multiple shared genomic 'mistakes' at identical positions such as pseudogenes, retrotransposons, endogenous retroviral elements, scars of DNA repair such as non-homologous end-joining, mitochondrial DNA in nuclear DNA, and ectopic telomeric DNA alone enough to make the case beyond reasonable doubt:
"Given the size of vertebrate genomes (>1 × 10^9 bp) and the random nature of retroviral integration, multiple integrations (and subsequent fixation) of ERV loci at precisely the same location are highly unlikely. Therefore, an ERV locus shared by two or more species is descended from a single integration event and is proof that the species share a common ancestor into whose germ line the original integration took place. Furthermore, integrated proviruses are extremely stable: there is no mechanism for removing proviruses precisely from the genome, without leaving behind a solo LTR or deleting chromosomal DNA." [4]
“When two lineages share what appears to be an arbitrary genetic accident, the case for common descent becomes compelling, just as the case for plagiarism becomes overpowering when one writer makes the same unusual misspellings of another, within a copy of the same words. That sort of evidence is seen in the genomes of humans and chimpanzees. For examples, both humans and chimps have a broken copy of a gene that in other mammals helps make vitamin C As a result, neither humans nor chimps can make their own vitamin C.     […]

“The same mistakes in the same gene in the same positions of both human and chimp DNA. If a common ancestor first sustained the mutational mistakes and subsequently gave rise to these two modern species, that would very readily account for both why both species have them how. It's hard to imagine how there could be stronger evidence for common ancestry of chimps and humans.”[5]
As one would expect given human-ape common ancestry, humans did not descent from two people living a few thousand years ago, and as such, population genetics studies would reflect a lack of a sharp bottleneck. This is precisely what we see:
“Studies based on SNP/LD approaches have now estimated ancestral population dynamics for various human groups over time in more detail than is possible with mutation-based estimates. African groups have a higher effective population size (~7,000) than do non-African groups (~3,000) over the last 200,000 years. This approach, though based on methods and assumptions independent of previous work, nonetheless continues to support the conclusion that humans, as a species, are descended from an ancestral population of at least several thousand individuals. More importantly, the scalability of this approach reveals that there was no significant change in human population size at the time modern humans appeared in the fossil record (~200,000 years ago), or at the time of significant cultural and religious development at ~50,000 years ago.

“Taken individually and collectively, population genomics studies strongly suggest that our lineage has not experienced an extreme population bottleneck in the last nine million years or more (and thus not in any hominid, nor even an australopithecine species), and that any bottlenecks our lineage did experience were a reduction only to a population of several thousand breeding individuals. As such, the hypothesis that humans are genetically derived from a single ancestral pair in the recent past has no support from a genomics perspective, and, indeed, is counter to a large body of evidence.” [6]
One could readily enumerate this evidence, but the point has been made. Human-ape common ancestry is a fact, and and any reading of the creation narratives which insists on universal human descent from two people living a few thousand years ago is untenable.

Wholesale science denialism is damaging enough to SCACP’s credibility, but the incoherence of his claim that evolutionary creationists “face the inconsistency of having evolution for the tree of life and all the primates except Adam, Eve and their descendants” demonstrates not just his ignorance of the science, but poor reasoning. The author of SCACP is hardly being logical when he begins his second paragraph with the contingency of evolutionary creationists accepting the special creation of Adam and Eve, then criticising them for not allowing a special creation of Adam and Eve. As for their descendants, the problem is one entirely of SCACP’s invention, as they would have intermarried with the existing population outside the garden whose origin was evolutionary. From a population genetics point of view, the introduction of any children of Adam and Eve into the large gene pool of the surrounding population would just be another example of gene flow from a tiny population into a much larger one.

SCACP continues with more bald assertion, coupled with profound ignorance of the scientific principles:
They exclude the empirical evidence of common descent from applying to Adam and Eve but without justification. They are in a bind
It is difficult to know what SCACP’s point is. As we do not have the genome of Adam and Eve, we cannot comment about it, so SCACP’s claim that evolutionary creationists ‘exclude the empirical evidence of common descent from applying to Adam and Eve” is very much justified. We don’t know what their genome looked like. Frankly, SCACP’s argument when stripped down is the old ‘Did Adam and Eve have navels?” which says everything for the sophomoric nature of SCACPs argument.

One can guess that SCACP is trying to argue that:
  • Adam would have to be ‘genetically compatible’ with the evolved population
  • That means possessing all the genomic quirks present in the human population
  • However, that means two people were specially created but with scars of an evolutionary history that never existed
  • Therefore, the scars of evolution in the current human population are not evidence of an evolutionary history for the human race.
If he is, then his argument is readily dismissed as it ignores the question of why God would put these ERV elements, retrotransposons, pseudogenes, scars of DNA repair, and ectopic telomeric elements in the human genome in the first place, given that they are almost always without function (whatever function they have is by secondary co-option of the genome). Ultimately, this is a variant on the Omphalos argument, and one that is no more convincing now than when Gosse first presented it in the 19th century.

It also fails to recognise that the genomic ‘errors’ are not static, but show an active history. For example, one member of the human endogenous retroviral family is still active, with some members showing marked insertional polymorphism, that is, present only in some humans populations:
 Only the HERV-K(HML2) family has been active since the divergence of humans and chimpanzees; it contains many members that are human specific, as well as several that are insertionally polymorphic (an inserted element present only in some human individuals). [7]
Likewise, retrotransposons also display polymorphism in the human genome
Due to their recent introduction into the human genome, many of the young Alu elements are polymorphic between individuals and/or populations. [8]
consistent with these elements being evidence of an actual past human evolutionary history. [9] When we see such genomic errors, what we see is unimpeachable evidence of human-ape common ancestry, but evidence that this process of retrotransposition, and retroviral insertion and integration is an active, ongoing process.

Any implied claim that Adam and Eve needed to be created 'genetically compatible' by being created with such 'scars of evolution' ignores the fact that the polymorphism in ERV and Alu elements alone means that people are able to interbreed without both people possessing the identical makeup of ERV and Alu elements, thus destroying the 'compatibility argument' and making the question about the genomic makeup of Adam and Eve not just irrelevant, but betraying SCACP's profound ignorance of comparative genomics and population genetics.

SCACP's argument once again shows not just the usual scientific illiteracy of the Christadelphian anti-evolutionists, but damningly, sophomoric logic and reasoning from someone with a professional background in philosophy.


2. Seely P.H.“The Firmament and the Water Above,”  Westminster Theological Journal (1991) 53: 227-40
3. Slifkin N "What the Firmament Really IsRationalist Judaism Jan 26 2011 Slifkin's remark that "people [should] read the definite study on this topic", namely the WTJ article by Seely (ref 2) serves as a neat rebuff to amateurish attempted rebuttals by non-specialists that have appeared in self-published vanity journals.
4. Johnson W.E, Coffin J.M. “Constructing primate phylogenies from ancient retroviral sequencesProc. Natl. Acad. Sci. USA (1999) 96:10254-10260
5.  Behe M The Edge of Evolution. The Search for the Limits of Darwinism (2007, Free Press) pp 71-72
6.Venema D.C. "Genesis and the Genome: Genomics Evidence for Human-Ape Common Ancestry and Ancestral Hominid Population SizesPerspectives on Science and Christian Faith (2010)  62:166-178

7. Belshaw R. et al “Genomewide Screening Reveals High Levels of Insertional Polymorphism in the Human Endogenous Retrovirus Family HERV-K(HML2): Implications for Present-Day ActivityJ. Virol. (2005) 79: 12507-12514

8. Roy-Engel A.M., et al “Alu Insertion Polymorphisms for the Study of Human Genomic DiversityGenetics (2001) 159: 279–290

9. “Identification of evolutionarily recent Alu subfamilies and their polymorphic insertions is useful for human population studies, forensics, and DNA finger-printing for two reasons: (i) There is no apparent specific mechanism to remove newly inserted Alu repeats, making inserts identical by descent; and (ii) the Alu insertions have a known ancestral state.” ibid,  p 279