[Guest Blog by Jon Peters, CFI-Portland]
April is an important month to commemorate DNA discoveries and announcements!
April 25 was DNA Day, celebrating the discovery of the structure of DNA. It was on that day in 1953 that one of the most significant scientific discoveries ever made became public as Nature published Watson and Crick’s paper announcing they had discovered the molecule of inheritance (Nature, 1953).
The opening of the article may go down as one of the biggest understatements of the twentieth century. Watson and Crick wrote, “This structure has novel features which are of considerable biological interest.” Right – surely they knew the Nobel Prize would be awaiting them in the future. And I love how they casually wrote toward the end, “It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for genetic material.”
April 25 also marks the anniversary of the completion of the Human Genome Project. The working draft of the genome was announced in 2000, but a more complete draft was announced on April 25, 2003, so last week we celebrated the tenth anniversary of the completion of the Human Genome Project as well as the sixtieth anniversary of the Watson and Crick publication. (In 2006, the last chromosome’s complete sequence was announced. Chromosome 1, the largest, took a while to complete.)
And there’s more. On April 5, 2010, biologists at the Christian website Biologos posted an article stating directly that evidence from human DNA analysis made it impossible for there to be a historical Adam and Eve.
The authors, Venema and Falk, detailed three different features of DNA that show the human race could not have derived from a single, specific couple: 1) allelic diversification, 2) Alu diversification, and 3) linkage disequilibrium. To summarize briefly, we inherit one half of a chromosome pair from each parent so the maximum number of alleles that each person can carry for a particular site on our chromosomes is two. Looking at the human genome today there are simply too many possible alleles to have come from a single pair of founding individuals who would have had only four different genes. Secondly, Alu repeats make up such a large portion of the human genome that they are scattered in too many different places on chromosomes to have come from a single pair of humans. Lastly, genes are often linked, being close to one another and inherited in blocks. As they are passed down through many generations, they eventually become broken. When looking at our gene clusters, the linkage data indicates too much diversification to be accounted for by a primal couple. All of this means there is no way for the Biblical story of Adam and Eve to be literally true.
A year after the Biologos article was posted the impact of human DNA findings on Abrahamic religions was detailed for the public more effectively in the cover story of the June 2011 issue of Christianity Today. This is an interesting read as theologians – especially conservative theologians – wrestle with what this new area of science means to their faith. According to the article, several seminary professors lost their jobs over this issue. Some Christians have even called the DNA discoveries and the falsification of the Adam and Eve narrative a “Galileo moment” for Christianity.
DNA inheritance across species lines argues against another significant biblical story: “The Fall.” Many Christians believe sin and resulting disease were introduced at a specific time in history as a consequence of “The Fall” of Adam and Eve. If this had been the case, there would be random errors and mistakes scattered around our genomes as a result of a supernatural intervention. Instead, however, we find shared genomic errors between species. Errors by Endogenous Retroviruses (ERVs) and pseudogenes nest into patterns of inheritance that demonstrate macroevolution. The errors nest in similar groups and become more divergent the more distant the evolutionary relationships, so, for example, humans and chimps share certain genetic errors compared to humans and gorillas. Additionally, the various broken ERVs and pseudogenes can be nested like Russian dolls thereby confirming the evolutionary fossil record that we already have. When comparing DNA protein sequences and another type of shared DNA insertion called transposons we see that whales come from an animal related to hippos. We also see that humans and chimps share a common ancestor. Because of this pattern, common design is out as an explanation and we are left with only common ancestry.
The implications of these DNA findings for certain religious beliefs are stunning. Not only does the DNA evidence conclusively argue against “The Fall,” but if there was no “Fall,” then according to Christianity at least, there was no original sin and thus no need for redemption and a savior.
Over the past few years, the ramifications of DNA findings have begun to dawn on theologians. Think of the irony: like all of us, theologians and believers carry the historical record of our species in their blood, the very record that has now led to the falsification of the foundational faith tenets they believe to be true.
My interest in this subject runs very deep and with passion, as the DNA findings hold the promise of negating much of the creationist narrative. As Sean Carroll wrote in his 2006 book, “The new DNA evidence has a very important role beyond illuminating the process of evolution. It could be decisive in the ongoing struggle over the teaching of evolution in schools and the acceptance of evolution in society at large.”
The search for important truths continues to move forward thanks again to science and the incredible discoveries in genetics and comparative genomics.
So, happy DNA Day – and month! It’s even more significant than you think.
Jon Peters is a family physician, an award-winning teacher and mentor, and an Affiliate Associate Professor of Family Medicine at Oregon Health and Science University. He is a member of the Advisory Board of CFI-Portland and the founder of its Secular Humanists of East Portland program.