Molecularizing evolutionary biology

Abstract

The encounter in the 1960s between molecular biology and evolutionary biology had short- and long-term consequences. Comparison of protein sequences suggested that evolution proceeded at a regular pace, obeying a molecular clock. It rapidly led evolutionary biologists to give neutral variations a larger role in their models. The development of genetic engineering technologies opened the door to progressive replacement of the abstract notions of gene and gene mutation hitherto used by evolutionary biologists by precise molecular descriptions. The precise structural and functional characterization of mutations assumed an increasing role and supported the introduction of a hierarchy between genes and between gene mutations that is clearly visible in evolutionary developmental biology. I will examine how far the accumulation of molecular data has challenged the Modern Synthesis established in the 1940s. In particular, different molecular mechanisms have been successively proposed to support a Lamarckian form of evolution. My conclusion will be that molecularization of evolutionary biology is still in its infancy, and that the Modern Synthesis will be replaced by a functional synthesis in which models of evolutionary biology and a description of molecular mechanisms will be intimately dovetailed.