Human=chin : Neandertal=no chin. Why?

There was an interesting programme on BBC2 a few days ago about the Lapedo Child; a possible Human/Neandertal cross breed.

In it, the morphology of the jaw bone was used as one way to identify Human or Neandertal remains.

Humans have chins and Neandertals don’t.

What the purpose of the Human chin if Neandertals managed perfectly well without?

No muscles seem to anchor to it to help chewing so why’s it there.

Robert J. Sawyer, Canada’s most prominent science-fiction writer (not counting Spider Robinson, who is a Yankee immigrant), is working on a trilogy called The Neanderthal Parallax, about an alternate Earth where Homo sapiens went extinct and Homo neanderthalensis became the dominant species. So far he’s published two volumes, Hominids and Humans. The third volume, Hybrids, should be out this September.

In the first book, the main character, a Neanderthal named Ponter Boddit, gets thrown from his world to ours (in a freak accident involving an experimental quantum computer) and has to make his away among our people, whom Neanderthals call “Gliksins.” Discussing hominid evolution with a Gliksin scientist, he explains that his people, based on the Gliksin fossils they have found, with braincases significantly smaller than a Neanderthal’s, concluded that Gliksins must have been really stupid. Therefore they theorized the chin must have been a “drool guard” – you know, because idiots drool.

Nice idea, I’ll have to read up on him.

The only idea I could think of for the chin was some sort of sexual display angle to chins(!), but this seems a little silly unless our prehistoric ancestors had some sort of a chin fetish!

The chin exists for historical reasons. Take a look at chimps, they display prognathism, meaning their teeth are far forward. Humans have had their teeth slide further back on the lower jaw. The chin is just a useless leftover.

I don’t have all the details of this, but that’s my basic understanding of the situation. A physical anthropologist could doubtless explain it better.

My understanding is that it isn’t so much we have a chin that sticks out, but rather that the rest of our jaw is receeded, like Sengkelat said.

It seems to me from my reading (and this is off the top of my head so if I am wrong I apologize aforehand) That the theory goes similiar to this: As we evolved in the hands and became more dextrous we could process food better. That combine with a “better” exploitation of natural resources made the massive chewing muscles of prior hominids unecessary ie we didnt need massive grinding muscles as the food was becoming easier to chew. So as the muscles in our faces shrank the bone also shrank. Physical Anthropology 101: big muscles need big bones to anchor onto, so when we no longer needed the big muscles we no longer needed the big bone structure. As previously mentioned the rest of our jaw shrank and that point out in front was left to torment future shavers:D

I have no chin too is that a curse or blessing ?

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neohumaniod, we generally permit reviving old threads in General Questions only for the purpose of adding new factual information. Since this post does not, I’m closing this thread. Please do not do this again.

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