A Comeback for Lamarckian Evolution?
13th June 2009
Read it.
In recent years, scientists have discovered that epigenetic changes–heritable changes that do not alter the sequence of DNA itself–play a major role in development, allowing genetically identical cells to develop different characteristics; epigenetic changes also play a role in cancer and other diseases. (The definition of epigenetics is somewhat variable, with some scientists limiting the term to refer to specific molecular mechanisms that alter gene expression.) Most epigenetic studies have been limited to a cellular context or have looked at the epigenetic effects of drugs or diet in utero. These two new studies are unique in that the environmental change that triggers the effect–enrichment or early abuse–occurs before pregnancy. “Give mothers chemicals, and it can affect offspring and the next generation,” says Larry Feig, a neuroscientist at Tufts University School of Medicine, in Boston, who oversaw part of the research. “In this case, [the environmental change] happened way before the mice were even fertile.”