Epigenetics: DNA Isn’t Everything
Research into epigenetics has shown that environmental factors affect characteristics of organisms. These changes are sometimes passed on to the offspring. ETH professor Renato Paro does not believe that this opposes Darwin’s theory of evolution.Epigenetics in action: experience alters DNA expression
James A. Shapiro: Epigenetics III: Epigenetic Control of Natural Genetic Engineering and Environmental Inputs into Evolutionary Change
In the last blog we saw how cells keep track of invading DNA and use that information to target copies for incorporation in silent chromatin. The ability of cells to silence mobile genetic elements and other invading DNAs is a key epigenetic control process maintaining genome stability in normal times, when growth and reproduction proceed smoothly. The silent elements and other natural genetic engineering agents do not disturb a genome that is functioning well.Transgenerational epigenetic inheritance: More questions than answers
But what happens when the going gets tough? Do the tough get going in the genome, generating change to get out of trouble? The answer is: Yes, they do. We know that all kinds of stress conditions activate natural genetic engineering processes. These stresses range from DNA damage, exposure to various poisons and lack of nutrients to infection, dehydration and too much salt.
Facts and History:
Epigenetic modifications are widely accepted as playing a critical role in the regulation of gene expression and thereby contributing to the determination of the phenotype of multicellular organisms. In general, these marks are cleared and re-established each generation, but there have been reports in a number of model organisms that at some loci in the genome this clearing is incomplete. This phenomenon is referred to as transgenerational epigenetic inheritance. Moreover, recent evidence shows that the environment can stably influence the establishment of the epigenome. Together, these findings suggest that an environmental event in one generation could affect the phenotype in subsequent generations, and these somewhat Lamarckian ideas are stimulating interest from a broad spectrum of biologists, from ecologists to health workers.