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Dawkins: A “Perfect Hierarchy” in the Tree of Life?

Casey Luskin
Photo credit: Fronteiras do Pensamento [CC BY-SA 2.0], via Wikimedia Commons.

Back in 2011, Paul Nelson wrote an article here, “For Darwin Day: False Facts & Dawkins’ Whopper,” which responded to a YouTube video in which Richard Dawkins was asked to give the “strongest, most irrefutable single piece of evidence in support” of evolution. Dawkins answered by claiming that if you take DNA from any two organisms on earth and compare the genes, “you find that it forms a perfect branching hierarchy.” 

3 Million Views

That video has now apparently been removed, but recently we were asked to comment on a similar video from 2009 with FORA.tv (which is still online) where Dawkins was asked to give “one sentence that would convince a creationist to seriously doubt their theory” or “convince a believer in God to really doubt their belief.” Dawkins declined to give a “sentence” but instead cited a “fact” or “observation” which he thought would do the trick. The video has now been viewed over 3 million times:

In the video, according to Dawkins, the best evidence for evolution comes from: 

the pattern of resemblances that you see when you compare the genes using modern DNA techniques actually looking at the letter-to-letter correspondences between genes. Compare the genes of any pair of animals you like — pair of animals, pair of plants — and then plot out the resemblances and they fall on a perfect hierarchy — a perfect family tree. And the only alternative to it being a family tree is that the intelligent designer deliberately set out to deceive us in the most underhanded and devious manner. Moreover the same thing works with every gene you do separately, and even pseudogenes that don’t do anything but are vestigial relicts of genes that once did something.

What’s the “Hierarchy”?

The “hierarchy” that Dawkins is referring to in the video is the tree of life that evolutionary biologists can generate by analyzing the degree of similarity between different parts of organisms, alive or dead. This allegedly shows how all organisms are related by common ancestry. Dawkins claims that as you sequence the same gene (or genes) from an animal or plant and compare the similarity relationships between them, they always show some similarity of sequence that suggests a kind of branching tree pattern where one gene derived gradually from another. Dawkins also claims that if you compare the tree-like pattern generated by looking at the same gene in different animals, you will get exactly the same tree as when you analyze a different gene in the same group of animals. Evolutionary biologists typically claim that patterns thus derived from the analysis of genes confirm the pattern of resemblances derived from analyzing the fossil record. This is why Dawkins says “they fall on a perfect hierarchy — a perfect family tree.” To his mind, the data provides spectacular proof of evolution and it would never be expected if intelligent design were true. 

False Claims All Around 

At the end of the video, Dawkins conflates young earth creationism with skepticism regarding Darwinian evolution — which are two separate issues — but never mind that. There are three main problems with Dawkins’s claim: (1) Phylogenetic conflict is common and the “hierarchy” is far from “perfect.” (2) Common design can produce tree-like data, to some extent. (3) Pseudogenes aren’t nonfunctional relics that refute intelligent design. Since we were asked to comment on the video, I’ll elaborate on these three points in three subsequent posts.