Thursday, 24 September 2015

Casey Luskin and the Discovery Institute get it wrong on Homo naledi

The reaction to the magnificent Homo naledi discovery from the YEC community as my previous posts on the subject have shown not only show their complete and profound ignorance of the subject, but have betrayed how hopelessly divided the YEC response is. When one YEC organisation claims the fossils are non-human animals, while another claims they are fully human, it is readily evident that YEC comments on palaeoanthropology are worthless.

Predictably, the militant YEC elements in our community have uncritically taken their lead from the YEC charlatans, as well as seizing on any contrarian view they can find from mainstream palaeoanthropologists in order to give a semblance of scientific credibility to their position. [1] The fact that these contrarian views have been ably refuted by members of the Homo naledi team neatly destroys the anti-Homo naledi arguments that have emerged in our community.

Apart from the usual YEC pseudoscientific organisations such as AiG, CMI, and ICR, the intelligent design special creationist group The Discovery Institute is another pseudoscientific organisation to which YECs in our community uncritically appeal in order to find pre-packaged responses to the evidence for evolution. Given the odium in which the DI is held  by mainstream scientists, its history of censorship of dissenting views, and its pitiful small and scientifically vacuous body of 'papers' which it claims support ID, its credibility, and that of the arguments it makes is non-existent.

One of its leading spokespeople is the lawyer (not scientist) Casey Luskin, who does not let his complete lack of expertise, qualifications, and research in palaeoanthropology and evolutionary biology from pontificating on Homo naledi. Given how poorly the mainstream scientific community received his book on human evolution, (co-authored with two non-palaeoanthropologists Douglas Axe and Ann Gauger whose anti-evolution arguments are likewise not taken seriously by the mainstream scientific community) one would not expect his ramblings on Homo naledi (non-peer reviewed and appearing not in the scientific literature but the highly controlled environment of an intelligent design website) to be anything other than poorly informed nonsense. That, as developmental biologist P.Z. Myers ably notes, is very much the case.

Luskin's attack is merely a concatenation of his utter ignorance of evolutionary biology and palaeoanthropology, based on his confused belief that evolution is a linear path, rather than a branching tree. This is behind the belief in 'missing links', a term that betrays a belief in evolution as a ladder, and makes no sense when we recognise that palaeoanthropologists are not looking for a fossil that is a direct ancestor of current life, but attempting to build up a family tree by use of the data from each fossil they find. As Myers notes:
When a creationist (or a journalist or even a scientist) starts babbling about missing links or lacking transitional fossils, you’re done. They’re ignorant of the science, and can be ignored. Especially when they do things like the following, and mangle the science.
For now, the promoters of Homo naledi are are calling it an “anatomical mosaic.” That terminology raises a red flag. In the parlance of evolutionary biology, it means the fossil is a strange organism that doesn’t fit well into the standard phylogeny.
No it doesn’t! A mosaic is what we expect. Please. No one believes that there was one true population of human ancestors that ascended in a continuous, linear path from Australopithecus to Republican presidential candidate. It’s all fits and starts, one group over here being shaped one way, another group over there changing another way, and occasionally two groups associate and produce offspring that mix and match the traits of both…and some succeed and some die out. No one expects legs to evolve at a continuous low rate, and heads to evolve at precisely the same rate, and that that rate is uniform for all populations everywhere.
In short, Luskin - and those who blindly parrot him - are simply engaging in good old fashioned straw-man thrashing, claiming that because the pattern of evolutionary change does not resemble a ladder, evolution is falsified:
Creationists expect that we’ll paint a picture of human evolution that’s straight and narrow, like this:
Real scientists tell them over and over that no, the history of human evolution looks more like this:
And then the creationists declare that because the stream of history doesn’t look like the first picture, evolution has been falsified. That’s all Luskin is doing here.
Indeed. This simple point - evolution is not a ladder but a tree - is one that I have made repeatedly, but given that evolution denialists continue to make this long-refuted claim, it is one that alas will need to be reiterated until those in our community who deny the fact of evolution recognise that they are merely highlighting their ignorance of the subject they criticise, and cease making claims that have been refuted long ago.

For those in our community who are looking for a credible, informed review of the Homo naledi story from a palaeoanthropologist and a  Christian, this BioLogos article by James Kidder, author of this excellent series on human evolution also at BioLogos is definitely one that should be read and re-read.


1. It is curious how they are happy to cite minority mainstream scientific views when it supports them, but reject the overwhelming mainstream consensus, particularly when almost all YECs in our community do not have the detailed scientific background in palaeoanthropology, population genetics, evolutionary biology, or genomics to be in a position to determine which views are sound, and which ones are not.