4 November 2005
Ollie Rando
Bauer Center for Genomics Research
Harvard University
Phenotypic variation and inheritance are two of the cornerstones of Darwin's theory of evolution. The double helical structure of DNA provided tremendous insight into the basic mechanisms of genetic inheritance, and phenotypic variation is widely understood to stem from mutations in DNA sequence. However, over the past decades it has become increasingly clear that biological systems have evolved mechanisms to stabilize phenotypes against mutation (called "robustness"), and conversely to allow rapid phenotypic change in the absence of mutation (broadly known as "epigenetic" inheritance patterns). Indeed, a number of mechanisms exist by which the cell may regulate its rate of phenotypic change. These varied biological phenomena are discussed within a framework based on the stability of an affected phenotype across generations.