Monday, 26 July 2010

Blog Focus - Panda's Thumb - What is evolution?

From Panda's Thumb;


It’s more than genes, it’s networks and systems


Most of you don't understand evolution. I mean this in the most charitable way; there's a common conceptual model of how evolution occurs that I find everywhere, and that I particularly find common among bright young students who are just getting enthusiastic about biology. Let me give you the Standard Story, the one that I get all the time from supporters of biology.

Evolution proceeds by mutation and selection. A novel mutation occurs in a gene that gives the individual inheriting it an advantage, and that person passes it on to their children who also gets the advantage and do better than their peers, and leave more offspring. Given time, the advantageous mutation spreads through the population so the entire species has it.

One example is the human brain. An ape man millions of years ago acquired a mutation that made his or her brain slightly larger, and since those individuals were slightly smarter than other ape men, it spread through the population. Then later, other mutations occured and were selected for and so human brains gradually got larger and larger.
You either know what's wrong here or you're feeling a little uneasy—I gave you enough hints that you know I'm going to complain about that story, but if your knowledge is at the Evolutionary Biology 101 level, you may not be sure what it is.

Just to make you even more queasy, the misunderstanding here is one that creationists have, too. If you've ever encountered the cryptic phrase "RM+NS" ("random mutation + natural selection") used as a pejorative on a creationist site, you've found someone with this affliction. They've got it completely wrong.

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