[Modernman]

"The mutation would have reduced the Darwinian fitness of those individuals," said anthropologist Bernard Wood of George Washington University. "It only would've become fixed if it coincided with mutations that reduced tooth size, jaw size and increased brain size. What are the chances of that?"

Interesting point. I wonder if anyone on this thread can come up with an explanation.

[thoughtomator]

Hmm... well I have noticed an inverse correlation between the size of a Democrat's mouth and their intelligence...

[AntiGuv]

I wonder if anyone on this thread can come up with an explanation.

The explanation is that it probably didn't make much, if any, practical difference to their ability to eat, and therefore had no impact on their ability to reproduce. Many people misconstrue evolutionary science to state that any mutation that is less clearly adaptive than another - however trivial and inconsequential to survival - will not perpetuate due to that initial reduction in fitness.

That is false. It's unfortunate that an anthropologist makes such an elementary error.

[wideminded]

"The mutation would have reduced the Darwinian fitness of those individuals," said anthropologist Bernard Wood of George Washington University. "It only would've become fixed if it coincided with mutations that reduced tooth size, jaw size and increased brain size. What are the chances of that?"

Interesting point. I wonder if anyone on this thread can come up with an explanation.

Some possibilities: If genes affecting these things were located near each other on the same chromosome, and damage occured to this region of the chromosome, then the mutated genes could possibly all pass together to an egg or sperm cell during the "crossover" stage of meiosis. Also, the connection between genes and physical characteristics is not one-to-one. It is possible that a change in only one gene could affect tooth, jaw, and brain. Or perhaps a sperm cell coding for reducing jaw and tooth size was mated with an egg containing a larger-brain mutation.