Neanderthal growth rate
There have been discussions here about Neanderthals
(not you, Mike Lee!) So you might be interested in the following
abstract of an article in today's issue of Nature. (If your library
access is like mine, you might get to read the article in a month.)
It is an interesting idea: Neanderthals, though intelligent, were
adapted for a low-tech, cold weather evolutionary niche. So maybe
they were a different species--the debate goes on.
---David
Life-history traits correlate closely with dental growth,
so differences in dental growth within Homo can enable us to determine
how somatic development has evolved and to identify developmental
shifts that warrant species-level distinctions. Dental growth
can be determined from the speed of enamel formation (or extension
rate). We analysed the enamel extension rate in Homo
antecessor (8 teeth analysed), Homo heidelbergensis (106), Homo
neanderthalensis ('Neanderthals'; 146) and Upper
Palaeolithic-Mesolithic Homo sapiens (100). Here we report that
Upper Palaeolithic-Mesolithic H. sapiens shared an identical
dental development pattern with modern humans, but that H.
antecessor and H. heidelbergensis had shorter periods of dental
growth. Surprisingly, Neanderthals were characterized by having
the shortest period of dental growth. Because dental growth is
an excellent indicator of somatic development, our results suggest
that Neanderthals developed faster even than their immediate
ancestor, H. heidelbergensis. Dental growth became longer and
brain size increased from the Plio-Pleistocene in hominid
evolution. Neanderthals, despite having a large brain, were
characterized by a short period of development. This autapomorphy
in growth is an evolutionary reversal, and points strongly to a
specific distinction between H. sapiens and H. neanderthalensis.
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Re: Neanderthal growth rate
David Hobby wrote: It is an interesting idea: Neanderthals, though intelligent, were adapted for a low-tech, cold weather evolutionary niche. So maybe they were a different species--the debate goes on. Because dental growth is an excellent indicator of somatic development, our results suggest that Neanderthals developed faster even than their immediate ancestor, H. heidelbergensis. Dental growth became longer and brain size increased from the Plio-Pleistocene in hominid evolution. Neanderthals, despite having a large brain, were characterized by a short period of development. This autapomorphy in growth is an evolutionary reversal, and points strongly to a specific distinction between H. sapiens and H. neanderthalensis. So Neanderthals really did live fast and die young. I guess since their creative, neotonous childhoods were so short, they wouldn't have had a chance to develop the kind of mental flexibility modern humans have. I've also seen speculation that they couldn't develop much culture, because they didn't have enough old people for oral tradition to start. If they grew up quickly, they may have also aged quickly, which would support that theory. __ Steve Sloan . Huntsville, Alabama = [EMAIL PROTECTED] Brin-L list pages .. http://www.brin-l.org Science Fiction-themed online store . http://www.sloan3d.com/store Chmeee's 3D Objects http://www.sloan3d.com/chmeee 3D and Drawing Galleries .. http://www.sloansteady.com Software Science Fiction, Science, and Computer Links Science fiction scans . http://www.sloan3d.com ___ http://www.mccmedia.com/mailman/listinfo/brin-l
