The attempt on the life of the Tree of Life: science, philosophy and politics

Lateral gene transfer (LGT), the exchange of genetic information between (primarily prokaryotic) lineages, not only makes construction of a universal Tree of Life (TOL) difficult to achieve, but calls into question the utility and meaning of any result. Here I review the science of prokaryotic LGT, the philosophy of the TOL as it figured in Darwin’s formulation of the Theory of Evolution, and the politics of the current debate within the discipline over how threats to the TOL should be represented outside it. We could encourage a more realistic and supportive public understanding of evolution by admitting that what we believe in is not a unified meta-theory but a versatile and well-stocked explanatory toolkit.