Philosophers, psychologists and scientists have long debated whether our behavior is largely the product of environmental influences (nurture) or mostly the consequence of our genetic make-up (nature). Modern discoveries in biology have confirmed the suspicion of many that it's probably a combination of both.
Research on rats suggests that environment can actually change an animal's genome (the genetic composition of an organism) and thus influence much of its behavior.
The part of the genome that appears to be affected by environmental factors is not the actual DNA, which is the chemical basis for our genes, but rather molecular tags (called methyl groups) that attach along the DNA and act as switches turning certain genes on and off.
These tags are collectively referred to as the "epigenome," and this five minute video explains how it's believed that the environment affects these elements of our genetic make-up.
The mystery, at least it's a mystery to me, still remains how the proteins coded for by our genes translate into behavior. How do strings of amino acids generate a behavior like licking the young, building a specific type of nest or migrating to a specific tree thousands of miles away (as Monarch butterflies do)?
There must be some connection between physical proteins and an organism's behavior, but if it's known I've never seen it explained.
Another mystery is how strings of amino acids can tell cetain types of cells to move to distant parts of the body, or tell certain chemicals in the cell to move to other parts of the cell. To compound the mystery why should anyone think that all these things and many, many more all evolved by chance through a blind, undirected process like Darwinian evolution.
If the Darinians expect us to believe it they ought to give us a possible explanation rather than vague promises that someday the explanations will all be forthcoming.
