Hi, Delta-9.
Welcome to EvC!
Delta-9 writes:
First, how can epigenetic traits be passed on to subsequent offspring, as seen with changes in mouse hair color, when epigenetic changes don't effect the DNA sequence of the organism? Does it have to do with some retaining trait of the chromosomes during meiosis?
I'm not a molecular biologist or geneticist, but I have taken the relevant coursework. Let me give you a few simple answers, and maybe an actual molecular geneticist (such as Wounded King) can provide you with something better.
For the lurkers, epigenetics refers to inherited traits that are not encoded in nucleotide sequences. Usually, it has to do with patterns of gene expression perpetuating after cellular division: expression of genes can be promoted or inhibited by certain proteins and other molecules in a cell. Some genes can be inhibited, and some can be promoted: differences in the patterns of inhibition and promotion can cause cells with identical genotypes to develop in different ways.
And, when a cell divides, its patterns of inhibition and promotion are often transmitted to both daughter cells. So, cells (including embryos) can inherit the expression patterns, and the resulting developmental traits, of their progenitors.
-Bluejay (a.k.a. Mantis, Thylacosmilus)
Darwin loves you.
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