Humanity Gene Found?

Banana_Republican writes "Nature is reporting that that multiple copies of a mystery gene may be what makes us human. It appears that humans have multiple carbon copies of a recently discovered gene that other primates lack. In particular, one sequence not so romantically or emotionally termed 'DUF1220' was mentioned . Humans carry 212 copies of DUF1220, whereas chimps have 37 copies, and monkeys have only 30 copies. Apparently the current thinking is that this gene is responsible for coding important areas of brain function."

Comments

Don't forget human antigenes

[Baldrson]

Although there are some critical genes for expression of human characters, one of the characteristics of rapid evolution seems to be the inactivation of genes. As you progress along the line to humans there appear to be fewer and fewer genes being expressed. This seems to be the result of mutation's default action which is to damage gene function which in general means to deactivate it. Its a lot easier to deactivate a gene than it is to create a gene with positive action. So you can expect that if there are ways to create positive characters at the phenotype level by deactivating genes that would be main way those characters emerge during the early stage of evolution. It is probably also be that some older genes need to be silenced to so that newer genes that actually do function can express less competition.

Re:Don't forget human antigenes

[andyr]

I heard that cancer was the oldest disease, and the careful countdown of cell generations from stem cells was precisely to keep the wart on the frogs bum from taking over the frog. Once you have licked cancer, the rest becomes manageable.

There's a gene that confers some resistance...

[exp(pi*sqrt(163))]

...to HIV. Chimps have more of them than humans. It seems likely that SIV (simian immunodeficiency virus) has existed in chimps much longer than HIV in humans. As a result, Chimps with more copies of the gene have outlived their less well endowed relatives and now almost all chimps can coexist with SIV without showing symptoms of immunodeficiency. Apparently humans have started making similar adaptations and in some areas of the world there is now a generation of humans who seem to do a fairly good job of coexisting with HIV. But all humans still have many fewer of these genes than chimps.

But nobody would make the mistake of saying that this gene is the gene for 'chimpness'. It's just an accident of history that SIV arose before HIV.

I learned all of this from an excellent podcast whose name I dare not write for fear of offence...

As I recall this is a flipped segment

[WillAffleckUW]

which was puzzling at first, because it's literally flipped around from the chimp gene, and actually is similar to a dog segment. Turns out a lot of what we thought were different gene segments folded wrong and literally reassembled upside down (backwards).

However, just remember that just because we may have found a segment doesn't mean we understand how it works. Sometimes, it's not just the genes it encodes, it's how it impacts other genes on other chromosomes, and how it misfolds or affects transcription errors.

Every day we learn more and more, and understand less and less. But it's fascinating work, and is leading to greater understanding of what makes us tick - even though we are all different and the variation among us homo sapiens is greater than the difference between homo sapiens and a chimp. Sometimes, you may find you may have more genetically in common with someone from Borneo when you're from Germany than you do with another person from Germany.

[note - if I'm wrong about the flip, my apologies, it's been a summer with few seminars - reading the papers is harder in some ways]