Terrapin Tables

Evolution in the News

Continuing my campaign for TT's biggest nerd...

Recently, there was a paper published in Nature about how a mutation to a gene that encodes for jaw muscles may have allowed humans to get bigger brains than other apes. Basically, the mutation keeps the body from producing a certain protein, which in turn keeps jaw muscles smaller. This seems reasonable enough. The author goes on to claim that this is responsible for our brains being larger. While this may be true in a sense, I think the author is putting the cart before the horse, and is greatly misleading the general public about how evolution works.

There's a quote from the author in Washington Post, stating, "Life would not have been easy for the first primates affected by the mutation, as they scrambled for survival with weaker jaws than their rivals." That's not the way the world works. If nothing else was different, animals with that mutation would not have been able to compete, and the mutation would have disappeared as those animals died. There must have been some occurence, either at the same time, or before the mutation, that made that mutation beneficial, or at least not harmful. My guess is that it was a behavioral change, probably a shift to easier to chew foods (more fruits and meat, less tough plant material), that made large jaw muscles unnecessary. Then, animals with the mutation would have been at an advantage by not wasting energy in growing those muscles. Then, the smaller jaw muscles could have lead the way to larger brains. But I think it's very misleading the way that he's published his paper, and the quotes that he's given, making it seem that there was just all of a sudden some mutation that let our brains get bigger.