Did a Genome Copying Mistake Lead To Human Intelligence? 381
A new study suggests that the sophistication of the human brain may be due to a mistake in cell division long ago. From the article: "A copyediting error appears to be responsible for critical features of the human brain that distinguish us from our closest primate kin, new research finds.
When tested out in mice, researchers found this 'error' caused the rodents' brain cells to move into place faster and enabled more connections between brain cells."
Re:Evolution (Score:4, Informative)
One type of error is duplication, when the DNA-copying machinery accidentally copies a section of the genome twice. The second copy can be changed in future copies — gaining mutations or losing parts. The researchers scanned the human genome for these duplications, and found that many of them seem to play a role in the developing brain.
[...]
An extra copy of a gene gives evolution something to work with: Like modeling clay, this gene isn't essential like the original copy, so changes can be made to it without damaging the resulting organism.
Not at all; completely on point (Score:4, Informative)
Mice and other critters may well have evolved the same mutation many times, but it had no survival benefit without other mutations which only humans (or primates) had.
Human speech, for instance, requires physical changes to vocal cords and the throat, in addition to brain changes, or so I have read. Got to change them all to get actual speech.
Re:Evolution (Score:5, Informative)
I think Richard Dawkins made it okay to use these quasi-anthropomorphic terms to describe processes of evolution when he titled his book "The Selfish Gene," so long as you constantly remind people, as he does laboriously in his text, that genes do not have wants, intentions, or consciously-implemented strategies. It's like saying photons are both a wave and a particle, I've read many physicists who point out that we use the wave-particle duality as a means of conceptualizing something so alien to our macro-reality into something we can understand so the non-expert can enjoy the wonder as well. So too do we attribute all sorts of human concepts to the algorithm of natural selection to make it easier to understand.
Still, your criticism is a valid one and something people need to be reminded that we are talking about inanimate processes.
Something that occurred to me reading the article was that when I saw the term "cell division" I immediately pictured a developing embryo, but that would be a somatic mutation rather than a germinal mutation [ndsu.edu]. It's important to remember that all these evolutionary mutations didn't happen in the animals, they happened in the animals' gametes, the sperm and eggs. A mutation that occurs in the cell division of a developing embryo wouldn't have any affect on the individual's gametes, the mutation had to occur in the sperm or egg first.
Re:Tree of Knowledge (Score:4, Informative)
Does this mean we can pinpoint the time and place of Eden, when Adam and Eve bit the apple that led to this cell division?
Well, using mitochondrial DNA, they have already found that all humans have a common mother some 200,000 years ago. As for the place, most scientist believe it was the eastern part of Africa. Probably not the answer you were looking for, though.
Re:Evolution (Score:5, Informative)
"The only "point" of evolution is survival." No, the only point of evolution is successful reproduction.
No, there is no point to evolution. It is simply a side effect of an imperfectly self replicating system (such as amino acid chemistry) in an environment that is non homogeneous.
Re:Evolution (Score:4, Informative)
"The only "point" of evolution is survival."
No, the only point of evolution is successful reproduction. It makes no difference how long you survive. If your genes aren't passed to offspring, any evolutionary change you may have had dies with you. Likewise, it makes no difference if you die after producing self-sustaining offspring - your contribution to the gene pool carries on.
Not necessarily. If you have no kids, but help other people's kids based on some criteria, you are inserting that criteria into the evolutionary selection pressure. If you take care of your nieces and nephews, you are promulgating kids who share some of your genes even if you don't reproduce. Even if the kids you care for have no genetic similarity, the fact that you were put into a position to care for them may select kids who are in some way similar to you (ie. probably share some genetic patterns). A strong society will likely raise stronger kids who happen to share a disproportionate number of genes with you.
Re:Evolution (Score:4, Informative)
His theory is actually vindicated by modern science; but it's not the theory of evolution but the theory of natural selection, as these two are quite distinct beasts.
His theory of evolution is well supported by modern science. Please recall that natural selection is but a third of evolution. We also have copious evidence both of inheritable traits that affect survivability and propagation of that organism's progeny, and variation of those traits over subsequent generations, the two things that need to be added to the theory of natural selection to get the theory of evolution.
Re:Not at all; completely on point (Score:2, Informative)
For anyone who has live in a cave for the last 40 years:
Mrs. Frisby and the Rats of NIMH [wikipedia.org]