As a scientist in my late 30s, I’m (just) old enough to have worked in the pre-genomics era. As a graduate student, I worked on an organism that did not yet have a completed genome sequence available, and I spent some of my time sequencing DNA the old-fashioned, manual way, with technology that is today hopelessly inefficient and out of date. The genomics revolution, driven by the human genome project, was coming, but it would take a few more years for the results to come in and the technology to drop in price.
Today, only a decade later, we live in a different world scientifically. Our ability to acquire and compare DNA sequences has grown exponentially. What was once enough sequencing work for an entire PhD can now be completed in an afternoon, with ease. We now have not only the entire human genome sequenced, but we’re sequencing scores of human genomes from individuals all over the globe.
Unfortunately, for many Christians this technological tour-de-force is nothing to celebrate. Yes, this work promises to help us diagnose diseases, tailor treatments to individuals and reduce suffering - all aims that strongly resonate with Christians. The problem is that in addition to these benefits, modern genomics has convincingly demonstrated two things about the human race that many Christians find troubling: that we came on the scene through an evolutionary process, and that we arose through an evolutionary process as a population numbering in the thousands.
The lines of evidence for these two conclusions are deep, and get deeper with each new study published. In the human genome we see clear marks of our evolutionary past - from defective genes used for making egg yolk (from a time in our lineage when our ancestors laid eggs, before lactation evolved) to patterns of mutations shared between our species and other primates (such as the mutation that destroys our ability to make vitamin C, which we share with chimpanzees, gorillas, bonobos and orangutans).
Studies on human genetic diversity in the present day show us that we are too genetically diverse to descend from only two individuals at any time in our evolutionary history. Studies have used many different measures of our diversity with different assumptions, yet have nonetheless agreed that the lineage leading to our species has never numbered below about 10,000 individuals. (And no, “Mitochondrial Eve” is no help here, despite widespread confusion about her among Christians.)
Of course, neither of these findings sit comfortably with the stories I remember well from Sunday School as a child; indeed, some Christian groups are beginning to require denying these findings as part of their theology. In particular, there is a concern that moving away from the view that the entire human race descends from one ancestral couple threatens the doctrine of original sin. (Examples here would include Mark Driscoll and the Evangelical Free Church of America.) These sorts of moves put scientifically knowledgeable believers in such groups in a difficult position - do they deny the science to remain theologically “on side,” or do they risk membership in their faith communities by accepting the science?
As the information coming out of the various genome-sequencing projects trickles down to the pew level, these difficulties are only going to increase. For believers who value God’s revelation both through Scripture and His creation, there is some serious theological work do be done here. And the sooner we start, the better.