At a deeper level, the book is a serious treatise on why we need to overhaul our views on heredity. Zimmer shows how the idea evolved from medieval times, with the passing down of possessions, to our modern focus on genes. He recounts how nineteenth-century genetics pioneers Gregor Mendel and August Weismann seemed to bring clarity by defining simple laws of inheritance in sexual organisms, and by distinguishing between sex cells in the germ line and cells in the rest of the body (see J. Maienschein Nature 522, 31–32; 2015). But heredity soon returned to a swamp of ambiguity. Charles Darwin’s cousin Francis Galton, a deeply flawed Victorian statistician and racist (who in 1904 founded what would become the Galton Laboratory at University College London) crops up repeatedly, each time with a new layer of nuance or downright murkiness.
It took the best part of a century for Mendelian genetics to be fully reconciled with complex hereditary traits such as height. Sophisticated statistical methods reveal such traits to be ‘omnigenic’, influenced by millions of genetic markers. Intelligence is even worse; fairly heritable, certainly, but with a complexity that mocks simple ideas of Mendelian inheritance. More.
Anyone remember when genetics was simple? The Central Dogma (DNA → RNA → protein)? Mendel and the peas? Dawkins and the selfish gene? Lecterns splintered more easily in those days…
See also: Researchers: “Phylogenetic comparative methods (PCMs) “deeply misleading,” “have sowed confusion”
Eugene Koonin on how CRISPR is leading to conceptual shifts in evolutionary biology
Oxytricha trifallax: A Russian doll set of confounding genetic complexity