Meeting Abstract

S1.2-1  Saturday, Jan. 4 09:30  Epigenetic Synthesis, or How Environmental Contamination Has Changed the Course of Evolution CREWS, David; University of Texas at Austin crews@mail.utexas.edu

Evolutionary theory accounts for the process of change in life forms. It has had two epochs. The first, Darwinian evolution, established the principle of change through selection. The second, the Modern Synthesis, provided the units of heredity and their control, particularly change in DNA by recombination and mutation. Until very recently species evolved in the absence of anthropogenic endocrine-disrupting chemicals, so the long-term evolutionary consequences of worldwide contamination are only now beginning to manifest. This fact of life today heralds a third epoch of evolutionary theory, or the Epigenetic Synthesis. This emerging perspective combines elements of the previous iterations and incorporates environmental modulation of temporal and spatial control of gene expression without altering the underlying DNA sequence. Molecular biology and genetics will continue to be the dominant disciplines in biology, and fortunately their practitioners have ‘re-discovered’ the importance of the environment. This has led to increasing research into molecular epigenetics and the interface between the environment and gene regulation. Another change is the realization that axioms such as ‘genes determine traits’ or GXE is more ideology than proof. In most situations it is how the genome is regulated, not the nucleotide sequence itself that is important. Ancestral exposures combine with significant events in the individual’s life history to determine the individual’s phenotype and likelihood of reproducing. Future research should focus on how two categories, namely germline-dependent and context-dependent epigenetic modifications, shape evolutionary change.