|
THE GENOME CHANGES EVERYTHING (p3) So one
important point is that genes are designed to produce human behavior
through nurture. But there's another phenomenon going on too, which
is equally important and which again people in these kinds of debates
over human nature have missed. They couldn't have failed to miss
it until recent molecular biology made a difference. That is, behavior
affects genes. It doesn't change the code of the gene, and it doesn't
change the encoded genome. Sure, you can change your encoded genome
by having a mutational accident, by flying in an airplane and having
cosmic rays damage your DNA. But what I'm talking about is changing
the expression of genes through things you do in your life. The encoded
genome is a set of DNA. The expressed genome is the RNA that's translated
from it and then made into proteins. That process of expressing the
encoded genome is controlled by transcription factors and all these
other things that interact with the promoters, which turn the genes
on and off and turn the volume of the genes up and down like thermostat
switches, or whatever analogy you want to use. That process is itself
at the mercy of the way we behave because you can do things in your
life that literally lead you to alter the expression of genes. That
process of changing the strength of synapses between nerve cells
is mediated by genes. It actually requires the switching on and off
of genes in order to change the synapses. These genes we now know,
because of work on fruit flies, are called the CREB genes. There
are about 17 of them in that particular system, and they're also
in mammals and humans as well. They prove that memory and learning
is a genetic process. That doesn't mean that it's a hereditary process—of
course not. What we're talking about here is changing the expression
of the genes in real life in response to what is literally the formation
of a new memory—a new experience, in other words. ~~~ |