We normally view evolution across a whole population level by considering changes in the traits of an organism, such as size, strength, hairiness or eye colour. Have you considered what is actually happening to an organism’s genes as it evolves?
David Ackerley (, Wellington)
Evolution is basically just a process of change, and it’s one that you can view in a number of different ways. You can view it at a whole population level, where it’s the ability of a population to adapt to changes in the environment. It can also be at a sort of individual level, where it’s survival of the fittest – if your genes are better than the person next to you, you've got a greater chance of surviving to pass on those genes in a competitive environment.
But all of theose things basically come down to the same deal, which is that, at a molecular level, it’s your differences in your genes that result in a different, or a different fitness, of one individual over another. And the idea is that the more fit individual, over time and probability, will have a better chance of passing on their genes to the next generation. And so, gradually, genes that are improved will start to predominate, and genes that are deleterious, or don't work so well, will drift away.
Jerry Crimson Mann
Christopher Walsh, Harvard Medical School