ABSTRACT
Novel epigenetic phenotypes can be induced both within an animal’s lifetime, as in cancer progression, and in the next generation, as by maternal diet. To modern biologists, the term epigenetics is broadly defined as “nongenetic inheritance.” The development of any multicellular organism from one undifferentiated cell to hundreds or thousands of cell types is an epigenetic phenomenon. In 1999, G. Cavalli and R. Paro showed that the polycomb response element, which epigenetically maintains the expression or repression of a gene during development, can also be transmitted through meiosis. M. K. Skinner and colleagues showed that endocrine disruptors can have transgenerational epigenetic effects. The transgenerational epigenetic ability of an endocrine disruptor to cause a disease in multiple generations has numerous implications in evolution. The epigenetic progenitor theory also has profound implications in the treatment of cancer because, for instance, treatment of benign tumors with radiation or chemotherapy, a common practice, could potentially increase the rate of later metastatic cancers.
