Genome complexity: how do genes exert control (Introduction)

by David Turell , Sunday, August 14, 2016, 23:05 (2806 days ago) @ David Turell

We can identify how genes relate to different functioning parts of an animal or plant, but we have no idea how that control is expressed:-http://www.wsj.com/articles/the-effect-of-environment-on-genes-1470938931-"Suppose scientists want to know what a gene—let's call it Gene Z—has to do with behavior. Using genetic-engineering wizardry, they generate a line of mice lacking Gene Z (“knockout” mice), plus another line with an extra copy of Gene Z (“transgenic overexpression” mice). Then they see if there's something different about the behavior of either group when compared with unmanipulated control mice.-***-"Genes like our fictional Gene Z, with “neurogenetic” effects on behavior, are often sensitive to small differences in the environment. Gene Z's effects on anxiety might differ between two labs because the mice in the two are fed different kinds of food; nutrition influences brain chemistry and thus potentially Gene Z's effects on the brain.-***-"People are often impressed with the deterministic power of genes, believing they explain everything about our biology and behavior. Many genes do indeed have consistent, powerful effects, but far more of them show a marked environmental dependency than most scientists had previously anticipated. Thus, what Dr. Crabbe and others show is that in many cases, you can't really say what a gene generically “does”—so perhaps be a bit skeptical about such pronouncements. Instead, you can only safely say what a gene does in the environment(s) in which it has been studied. -"This is pertinent to mice living in different laboratories. But just imagine how much that would apply to a species that can live in dramatically different environments—in deserts, tundra and rain forests, in hunter-gatherer bands and in dense cities, in close-knit communities or as hermits. There is no species that matches humans in the range of ecosystems, habitats and social system in which it lives. And that suggests there is no species freer from the power of genes than humans."-Comment: This article looks at the possible epigenetic environmental changes in genetic studies. It clearly shows we do not know how genes exert their controls. All we can see is what gene is related to what function and the environment may well alter that function. What this all means is that we recognize the genome does more than just code for proteins, but we are still just at the beginning of how to understand the multitude of layers of functional controls that must be present, especially the HAR's, the human accelerated regions that produce evolutionary jumps just presented yesterday. I continue to believe it is not be chance.