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DNA Comparisons between Humans and Chimps: A Response to the Venema Critique of the RTB Human Origins Model, Part 3

Is the RTB model for the origin of humanity valid? Biologist Dennis Venema doesn’t think so. In a recently published critique, he evaluates the portion of our model in which we address genetic similarities between humans and chimps.

As part of our assessment of human evolution, we question whether the genetic connection between humans and chimps is as strong as is commonly communicated to the general public. Most people are familiar with the claim that human and chimpanzee DNA share a 99 percent similarity. Our assertion, however, is that the genetic commonality between these two primates is closer to 90 percent.

Instead of discussing the scientific merits (or lack thereof) of our approach (which we welcome), Venema chose to launch an ad hominem attack against me and Hugh Ross, impugning our integrity as scientists and scholars. The crux of his criticism was that:

  1. We intentionally ignored a key scientific paper (published in 2005 after our book Who Was Adam? was released)about genetic comparisons between humans and chimpanzees that went against our model.1
  2. We claim erroneously that the genetic similarity between humans and chimpanzees is around 90 percent, not 95 percent (or about 99 percent) as the above mentioned paper reports.
  3. We misrepresent scientific opinion when we claim that the genetic comparisons between humans and chimpanzees that describe the differences (or similarities) in terms of percentages are meaningless.

I have already responded to Venema’s first two points. (Go here and here to read parts one and two of my response, respectively. This week, I will address the third point Venema raises.

In Who Was Adam? we provide an extensive discussion as to why “percent genetic comparisons” have no biological meaning. As a follow up in 2007, we published a web article that makes the same point. In fact, we go one step further in the article and point out that the emphasis on percent genetic similarity actually hinders our understanding of the genetic basis for the biological and behavioral differences between humans and chimpanzees.

Contrary to the concern raised by Venema, the view that genetic similarity lacks biological meaning is not exclusive to RTB—it is a point that has been forcefully made by several scientists working in comparative genomics.

Interested readers can check out the article I wrote in 2007 for further detail.

Part 1 | Part 2 | Part 3 | Part 4 | Part 5 | Part 6