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The historical Adam (2): Facing all the arguments

January 2016 | by Paul Garner

In November’s issue of Evangelical Times we introduced the debate now taking place among professedly evangelical theologians about the historicity of Adam.

Debate

This debate has been fuelled by scientific advances in the fields of genetics, population studies and palaeontology. But how compelling are the arguments?

Genetic data

Our knowledge of genomes has expanded rapidly in the last 15 years. Between 2001 and 2004 the human genome was published, and the chimpanzee genome followed in 2005.

Publication of these genomes allowed comparisons to be made that revealed a striking degree of similarity between the two species.1

The overall gene sequence similarity is about 95 per cent. Comparison of only the protein-coding sequences brings the similarity to about 99 per cent. Even more remarkable is the similarity when non-functional gene sequences are compared.

The mutations that have apparently rendered these genes non-functional are identical in both species. These genetic data seem to support the evolutionary claim that humans and the great apes shared a common ancestor a few millions of years ago.

Population data

In addition, modern day genetic variation can be used to estimate the size of ancestral human populations at various points in the past.

Studies based on the observed genetic diversity within our species, Homo sapiens, have led scientists to conclude that there must have been an ancestral population of several thousand individuals around 200,000 years ago (the conventional date for the origin of Homo sapiens).

Such studies seem to undermine the biblical claim that humans were genetically derived from a single human pair in the recent past.

Fossil data

As well as the data from genetics and population studies, we also have a growing database of fossils. Some 15-20 hominid species are now known from the fossil record.

These species include: (1) the ape-like, but bipedal, australopithecines; (2) poorly known fossils, called habilines, with cranial capacities larger than the typical australopithecine; (3) the erectines, essentially modern from the neck down, but with archaic skull traits; (4) and the Neandertals, short and stocky, with low-domed skulls and prominent brow ridges.

Conventional dates for their first appearances in the fossil record match evolutionary expectations: australopithecines (4.2 million years ago [mya]), habilines (2.8 mya), erectines (1.9 mya) and Neandertals (0.25 mya).

Response

So how should we respond to these evolutionary arguments?

First, let’s consider the genetic data. Some suggest that the sequence similarity of human and chimpanzee genomes has been overestimated, and is in fact closer to 70 per cent.2 But the fact remains that there is a high degree of similarity between humans and chimpanzees, whether that similarity is 99 per cent, 95 per cent or 70 per cent.

The more pertinent question is, what does this similarity mean? At the moment, creationist theories of biological similarity are in their infancy, and so it is not possible to provide a completely compelling creationist answer, although biologist Todd Wood has set out some principles that could guide future research in this area.3

But an important thing to note is that the genetic data does not really constitute a new argument at all. The argument for common ancestry based upon biological similarity has been around since at least the time of Darwin — and this is the same argument applied at the genetic level.

If Christians were not persuaded of evolution by the old version of the argument from similarity, it is difficult to see why they should find the new version any more compelling. We must beware the temptation to rewrite traditional Christian teaching in order to accommodate what is actually an old argument in modern garb.

Assumptions

Then we have the argument based on the ancestral population size of Homo sapiens. As currently formulated, this argument faces an obvious problem: it assumes that the only true humans are those belonging to Homo sapiens.

But if, as young-age creationists propose, Neandertals and Homo erectus (and possibly some other hominids) are also descendants of Adam and Eve, then population studies of Homo sapiens are looking at only a subset of human genetic diversity.

As Todd Wood has pointed out: ‘To get an estimate of the true ancestral human population size, you’d have to include genes at least from Neandertals and erectus, if not other species. I’m not saying that this solves the problem by any means, but it would at the very least render this [population] argument inconclusive until such time as a more comprehensive evaluation could take place’.4

Finally, there are the hominid fossils. Here we have some good reasons to question the conventional interpretation of the data as evidence of an evolutionary transition.

Creationists have traditionally suggested that the hominid fossils can be divided into two groups: those that represent types of extinct apes and those that belong to the human family.

In 2010 this claim received some impressive support from a statistical study of several living and fossil species, which found evidence of significant morphological gaps between humans on the one hand (Neanderthals, erectines and habilines) and non-humans on the other (australopithecines and chimps) — just as we might expect based on the Bible’s account of the separate creation of humans and non-humans.5

In February’s guest column we will explore some of the adverse theological consequences of questioning the biblical teaching on the historical Adam.

Paul Garner MSc, FGS is a researcher and lecturer for Biblical Creation Ministries (www.biblicalcreationministries.org.uk). His Master’s degree is from University College, London, where he specialised in palaeobiology. His first book, The New Creationism, was published by Evangelical Press in 2009.

References:

1. D. Venema, ‘Genesis and the genome: genomics evidence for human-ape common ancestry and ancestral hominid population sizes’; Perspectives on science and Christian faith, 62:166-178, 2010.

2. J. P. Tomkins, ‘Comprehensive analysis of chimpanzee and human chromosomes reveals average DNA similarity of 70 per cent’; Answers research journal, 6:63-69, 2013.

3. T. C. Wood, ‘The chimpanzee genome and the problem of biological similarity’; Occasional papers of the baraminology study group, (7):1-18.

4. Wood, T. C. 2010. ‘Venema’s Genesis and the genome’; http://toddcwood.blogspot.co.uk/2010/11/venemas-genesis-and-genome.html

5. T. C. Wood, ‘Baraminological analysis places Homo habilis, Homo rudolfensis, and Australopithecus sediba in the human holobaramin’; Answers research journal, 3:71-90, 2010. Note that one australopithecine species, A. sediba, clustered with the humans in this study; but some evolutionary anthropologists think that A. sediba should actually be classified as Homo sediba.

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