Pilot Project: Role of Epigenetics in Evolutionary Biology: Darwin’s Finches Model

The current paradigm regarding the molecular mechanisms that drive evolutionary change are solely genetic. The concept is that random DNA sequence mutations are the ultimate source of genetic variation, which is then augmented by other genetic processes such as random genetic drift, segregation and hybridization. These sources of heritable variation are the basis for evolution in response to natural selection, which acts on phenotypes. One problem with this paradigm is that the frequency of adaptive genetic mutations is so low that it has difficulty explaining the speed at which evolution occurs. The proposed research will investigate the additional molecular mechanism of environmental epigenetics. We will test the hypothesis that environmental effects can trigger heritable change in the epigenome that facilitates evolutionary events, including speciation. Using Darwin's Finches in the Galapagos Islands as a model, we have preliminary data suggesting that the degree of epigenetic change between species is greater than genetic change. The proposed research will rigorously test the hypothesis that environmental epigenetics may be an equally important molecular factor in evolution and provide insights into how environmental influences on the epigenome can play a role. Although the environment is already considered a major driver in evolution as an agent of natural selection, the new paradigm differs from the current one in evolutionary biology, not because of a role of the environment, but because the environment can more directly influence heritability rather than having to wait to act on heritable traits that come about by genetic mutation alone. Therefore, the research will examine a neo-Lamarckian concept that facilitates neo-Darwinian evolution - a revolutionary advance in our current paradigm.