For most of us, when we think of evolution we think of Charles Darwin and natural selection. Thanks to high school biology and cheesy motivational posters we are all familiar with the idea “only the fit survive.” Unfortunately, many of us don’t know what this actually means. Claiming only the fit survive creates a bit of a problem. How do you test this, and what exactly makes a “fit” organism? Perhaps most importantly, what do all of these questions mean for us as modern humans?
In his new book “Ancestors in Our Genome,” molecular anthropologist Eugene E. Harris tackles these questions from the perspective of population genetics.
Harris begins the book with a history of the contemptuous debates held by paleo-anthropologists and population geneticists. Traditionally, paleo-anthropology held the field of human evolution all to themselves. Our knowledge of human origins came exclusively from finding fossils and interpreting what they meant. This provided many useful insights, but it was quite subjective.
In his book, Harris explains how new genetic analyses have revolutionized our understanding of human origins. The ability to read DNA means we are no longer relegated to the subjectivity of bone morphology and new findings continue to arise. These discoveries make a reader wonder what other secrets our family tree holds, as there appear to be so many unsolved mysteries.
With all of these scientific conundrums, it’s a shame they aren’t explored more thoroughly. Harris spends what felt like hours discussing the phylogenetic process. While this process is important, as it allows us to deduce a family tree, he leaves untouched many of the great riddles that still plague our evolutionary past.
The book gets a bit more applicable when Harris explains how the explosion in population genetics could help inform modern medicine. Through periods known as population bottlenecks (a drastic reduction in population size), certain populations lost genetic variability. These groups are thus more susceptible to certain heritable illnesses like Tay-Sachs disease, Marfan syndrome, and Angelman syndrome. The book also explores the insights that population genetics can offer us about public health and our modern obesity epidemic.
