3.5 Extended Evolutionary Synthesis

More than seventy years after the Modern Synthesis and hundreds (thousands?) of research papers, a new idea is beginning to emerge. Science is uncovering the role of genetics, ecological factors, social factors, and developmental factors in the evolution of populations, and by extension, species. Shortly after the turn of the millennia, the idea of an Extended Evolutionary Synthesis (EES) was being debated in the scientific community.

By the late 20th century, it had become clear that evolution and inheritance involved more than simply passing genes. Rather, the processes that create selection pressures could also be environmental or anthropogenic. We now know that this is because evolution works on the phenotype, not the genotype. Additionally, as we unpacked the nuances of genetics, it became clear that genes were not static (or canalized). In fact, many genes are flexible (or plasticity).

To address this new leap in knowledge, the EES sought to view evolution as an interaction between genes and the environment. Rather than assume genetics trumps all, and macroevolution is the only source of change, the EES incorporates evolutionary developmental biology (aka, evo-devo), developmental plasticity, inclusive inheritance, and niche construction. Ironically enough, this idea was already suggested by an ethologist in 1963.