Re: Homo came from Asia?
- From: Marc Verhaegen <m_verhaegen@xxxxxxxxx>
- Date: Sat, 01 Nov 2008 10:58:54 +0200
http://www.sciencedaily.com/releases/2004/10/041001092127.htm
Southern exodus. A trail of stone tools and fossil bones suggests that early
humans left Africa 1.8 million years ago. Some headed north to Dmanisi,
Georgia; others may have taken a southern route into China and Java,
Indonesia. Ann Gibbons 7.10.08 ScienceNOW
http://sciencenow.sciencemag.org/cgi/content/full/2008/1007/3?etoc
Over a million years ago, a band of early humans left their stone tools and
two front teeth near a stream in southwest China. For decades, the precise
age of the fossils has remained a mystery, leaving open a central question
in paleontology: How quickly did our human ancestors reach China after
leaving Africa? Now, thanks to advanced dating techniques, scientists may
finally have the answer. ...
Now, a team of Chinese and American researchers has redated the Yuanmou
Basin site using a paleomagnetic technique that relies on rock samples to
determine the direction of Earth's magnetic field when the rocks were
formed. Although the original hillside where the fossils were found has been
excavated, the discoverers recorded the layer of sediment where they
uncovered the teeth and tools. The new team traced that sediment layer--or
time horizon--throughout the basin, collecting 318 rock samples from it. In
an article in press in the Journal of Human Evolution, the researchers
report that the fossils came from a layer of rock just above a magnetic
landmark known as the Olduvai-Matuyama reversal boundary, which is at least
1.77 million years old. This makes the fossil site slightly younger, about
1.7 million years old.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WJS-4GFCSW2-1&_user
=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_url
Version=0&_userid=10&md5=94fbe698d4f77c3db6d3a23fc9b1ebd4 or
http://tinyurl.com/crf6m
JHE 49:230-240
First occurrence of early Homo in the Nachukui Formation (West Turkana,
Kenya) at 2.3-2.4 Myr ... In 2002 a new PA site (LA1 alpha),
100 m S of the LA1 archaeological site, produced a first right lower
molar of a juvenile hominid (KNM-WT 42718). The rel.small size of the
crown, its marked MD elongation & BL reduction, the rel.position of
the cusps, the lack of a C6 & the mild expression of a protostylid,
reinforced by metrical analyses, demonstrate the distinctiveness of this
tooth compared with A.afarensis, anamensis, africanus &
Par.boisei, and its similarity to early Homo. The LA1 alpha site
lies 2.2 m above the Ekalalei Tuff which is slightly younger
than Tuff F dated to 2.34 ± 0.04 Ma. This juvenile specimen represents
the oldest occurrence of the genus Homo in WT ...
Thanks, Travsky, sensible answer, better than your usual idiocies.
But this has been discussed here already:
me:
1) Some retroviral data suggest that our *ancestors* after the H/P split c
5 Ma lived outside Africa for some time (at least between 4 & 3 Ma,
say CT Yohn cs 2005 PLoS Biol.3:1-11).
Hanenburg:
If you've read that paper then you know that's not the only
explanation for the absence of PTERV1 in humans.
title: Lineage-Specific Expansions of retroviral insertions within the
Genomes of African Great Apes but Not Humans and Orangutans
... Comparison of human and other primate genomes provides evidence for a
retroviral infection that bombarded the genomes of chimpanzee and gorilla
between 3 and 4 Ma ...
- you have 0 indications our ancestors were in Africa then
Except for the fossil bipedal hominids from that period on that
continent?
still confusing vertical & bipedal...
sigh
again
- all living hominids (HPG) had more bipedal (wading/hanging) ancestors
- all living apes (incl.gibbons) had vertical ancestors (Moroto lumbar
vertebra 19 Ma)
afarensis had curved phalanges (branch-hanging), found in swamp forests,
their diet included AHV, large airsacs, bipedal features, vertical posture,
thick enamel etc., resemble gorillas, but smaller & less KWing, their
dentition & locomotion suggests they spent more time in forest swamps
feeding on AHV than lowland gorillas, fruits, waterside plants & presumably
hard-shelled invertebrates google "Shabel durophage"
= example of how Afr.ape ancestors lived
= parttime bipedal & +-always vertical (in swamp & in branches)
- you have 0 indications they were no in Asia then
Except for the lack of fossil bipedal hominids from that period on
that continent?
- fossil record = fragmentary (esp.coasts)
- bipedal hominids in Africa might be closer related to P or G than to H
- still confusing ancestors (retroviral data) & fossils (no ancestors)
only fools believe far-fetched explanations first
Indeed.
good you admit
Anyway, between 3 and 2 Ma derived Homo-like morphology appears in
Africa.
in your fantasy, my boy: no very long legs, no ext.nose, no very large brain
Those are not the exclusive criteria by which we judge a specimen to
be Homo, See Strait & Grine (2004) "Inferring hominoid and early
hominid phylogeny using craniodental characters: the role of fossil
taxa", JHE 47: 399-452.
those are
the criteria traditionally used to discern Homo ("bipedality", dentition
etc.) ar primitive for hominids
http://users.ugent.be/~mvaneech/Fil/Verhaegen_Human_Evolution
2) No *fossil* data contradict this: the first undoubted Homo fossils
(ext.nose, CC > 600 cc, very long legs etc.) are found in Dmanisi &
probably Mojokerto c 1.8 Ma.
As Kimbel et al. argue the Hadar maxilla clearly belongs in the Homo
clade on the basis of the following derived characters:
-Reduced subnasal prognathism (index of .63 outside apith range).
-Clivus strongly angled to the nasal platform with distinct crista
spinalis and elevation of the anterior nasal cavity floor.
-Relatively broad palate (shape index >60% and outside apith range).
-Anterior division of maxillary sinus.
-narrow M1.
-rhomboidal M2
-P3 with vertical lingual face, elevated mesial
marginal ridge, buccal face basal symmetry, straight buccal enamel
line, and lack of strong mesial buccal groove; and P4 with vertical
lingual and buccal faces and hint of distolingual crown abbreviation.
-Thin molar enamel.
they say it was no robust apith, but that doesn't imply, my little boy, that
it was close to us
Kimbel et al. explicitly state: "The Hadar maxilla A.L.666-1 clearly
belongs in the Homo clade". That means it is closer to us than to any
australopithecine s.l.
- they think apelike = primitive
- if you start from the wrong preassumptions, you can prove what you want
- that a feature is closer to H than to P or G, doesn't mean it's H: in some
instances P & G are more primitive, in others H is
- that is was unlike apiths doesn't mean it belongs to H
a *little* bit of logic please
IOW, I don't care where Homo originated, but Africa is not certain.
That's all.
So far Africa holds the best cards.
in your fantasy, yes
Fantasy has nothing to do with it. It's a matter of comparative
morphology, stratigraphy, and secure radiometric dating. All within
the domain of science.
- if you start from the wrong preassumptions (eg, "bipedality" means human),
your "science" is fantasy
- if you don't use all the evidence (eg, Yohn cs above, comparative
biology...), your "science" is a bunch of prejudices
.
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