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Marc Verhaegen
Posted: Sun Jun 03, 2007 8:42 am
Guest
Paul O¹Higgins & Sarah Elton 2007
"Walking on Trees"
Science 316:1292-4
Observations of modern orangutans suggest that human bipedalism may have
evolved in the trees rather than on the ground.

The paper (can be found in the paleoanthropology files or at AAT
http://groups.yahoo.com/group/AAT ) discusses the recent paper of S.Thorpe,
R.Holder & R.Crompton 2007 Science 316:1328.
Some comments:

- Refs.2-3 are about Oreopith (+-8 Ma, found on an island in the Med.Sea
then, lived +-1 My earlier than Sahelanthr, +-1 My later than Samburupith).
Not not everybody accepts that Oreopith was (wading? parttime? aquarboreal?)
bipedal. In any case, it's obvious that "BPism" does not define everything
that is closer to Homo than to Pan, since (some sort of) BPism predated the
Homo/Pan split (+-5 Ma).

- Contrary to what some AATers still think, BPism has not much to do with
diving-swimming (only penguins are BPal on land) or wading (hippos, tapirs,
babirusas etc. are QPal), but everything with arborealism (indris, tarsiers,
gibbons etc. are "arboreal bipeds" = arm-assisted, mostly with BHBK). IOW,
"Walking on trees" is an excellent title .

- Why aren't gibbons discussed? Gibbons are more bipedal than orangs (both
in the trees), so if some sort of BPism predated the HPG/Po split (+-15 Ma),
it most likely also predated the Hy/PoHPG split (+-18 Ma).

- Bent-hips-bent-knees vs "straight" legs. The paper calls Pan locomotion
BHBK, but this is still very different from hopping as in tarsiers & indris.
We have to discern different sorts of BPism: hopping vs striding (small
birds hop more frequently than larger spp), BKBH-striding (Pan) vs
straight-legged striding (Homo, Pongo?), short- (apes & apiths) vs long-
legged (only Homo), etc.

- The paper doesn't mention the aquarboreal model & the delta model of
BPism. Unforgivable: ill-informed? Refs below.

- Yes, as I have argued innumerable times, Pan & Gorilla KWing are parallel
adaptations (ref.11=Dainton+Macho, but esp.Inouye has written several papers
on anatomical & ontogenetic differences between P & H KWing). P & probably
also G KWing postdate the H/P split (+-5 Ma).

- As the authors say, anatomical evidence for BPism can't be used for
defining "hominins" (=Homo+apiths). I've been arguing this for ages (see my
Hum.Evol.papers, refs below). In fact, nothing can be used for defining such
a taxon (whether it's called "hominin" or "hominid" or whatever): it's
paraphyletic: there no unique-derived features that discern Homo+apiths to
the exclusion of the rest, eg,
-- Thick or even superthick enamel (Ouranopith, Sivapith, Griphopith,
Afropith etc.) predates the H/P split (+-5 Ma) & even the hominid/pongid
split (+-15 Ma).
-- Apith-like canines predate the H/P split (eg, Wolfpoff etc.2006 "An Ape
or the Ape: is the Toumaï Cranium TM 266 a Hominid?" PaleoAnthropology:
36-50).
-- Sort-legged BPism predates the H/P split (see above).

Conclusion:
Orangutan "BPism" is derived from an earlier sort of BPism already present
in the hominoid LCA, IOW, it's no model for the origin of human locomotion,
but it can be used for reconstructing the hominoid LCA's locomotion.

IMO the origins of human (obligate) BPism & ape (parttime) BPisms are most
parsimoniously explained by an aquarboreal model, eg, wading on 2 legs &
climbing arms overhead in coastal or flooded or swamp forests swamps, where
+-all Miocene fossils (with the possible exception of Ouranopith // robust
apiths later?) are found, eg, in search for aquatic herbaceous vegetation
(cf.Ndoki gorillas wading in forest swamps), mangrove oysters (capuchins)
etc.

--Marc
http://allserv.rug.ac.be/~mvaneech/Symposium.html
http://groups.yahoo.com/group/AAT

- M.Verhaegen, P-F.Puech & S.Munro 2002 "Aquarboreal ancestors?" Trends in
Ecology & Evolution 17:212-7 (can be found in the AAT files or by googling
"aquarboreal")
- R.Wrangham 2005 "The Delta Hypothesis: hominoid ecology & hominin origins"
in D.Lieberman, R.Smith & J.Kelley eds. "Interpreting the past: essays on
human, primate & mammal evolution in honor of David Pilbeam" Brill
Ac.Publishers Boston: 231-242

http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html
- M.Verhaegen 1990 "African ape ancestry" Hum.Evol.5:295-297
- 1992 "Did robust australopithecines partly feed on hard parts of
Gramineae?" Hum.Evol.7:63-64
- 1994 "Australopithecines: ancestors of the African apes?"
Hum.Evol.9:121-139
- 1996 "Morphological distance between australopithecine, human and ape
skulls" Hum.Evol.11:35-41
Back to top
Marc Verhaegen
Posted: Sun Jun 03, 2007 4:03 pm
Guest
Op 03-06-2007 15:42, in artikel C28891F3.2E13%m_verhaegen@skynet.be, Marc
Verhaegen <m_verhaegen@skynet.be> schreef:

Quote:
Paul O¹Higgins & Sarah Elton 2007
"Walking on Trees"
Science 316:1292-4
Observations of modern orangutans suggest that human bipedalism may have
evolved in the trees rather than on the ground.

The paper (can be found in the paleoanthropology files or at AAT
http://groups.yahoo.com/group/AAT ) discusses the recent paper of S.Thorpe,
R.Holder & R.Crompton 2007 Science 316:1328.
Some comments:

- Refs.2-3 are about Oreopith (+-8 Ma, found on an island in the Med.Sea
then, lived +-1 My earlier than Sahelanthr, +-1 My later than Samburupith).
Not not everybody accepts that Oreopith was (wading? parttime? aquarboreal?)
bipedal. In any case, it's obvious that "BPism" does not define everything
that is closer to Homo than to Pan, since (some sort of) BPism predated the
Homo/Pan split (+-5 Ma).

- Contrary to what some AATers still think, BPism has not much to do with
diving-swimming (only penguins are BPal on land) or wading (hippos, tapirs,
babirusas etc. are QPal), but everything with arborealism (indris, tarsiers,
gibbons etc. are "arboreal bipeds" = arm-assisted, mostly with BHBK). IOW,
"Walking on trees" is an excellent title .

- Why aren't gibbons discussed? Gibbons are more bipedal than orangs (both
in the trees), so if some sort of BPism predated the HPG/Po split (+-15 Ma),
it most likely also predated the Hy/PoHPG split (+-18 Ma).

- Bent-hips-bent-knees vs "straight" legs. The paper calls Pan locomotion
BHBK, but this is still very different from hopping as in tarsiers & indris.
We have to discern different sorts of BPism: hopping vs striding (small
birds hop more frequently than larger spp), BKBH-striding (Pan) vs
straight-legged striding (Homo, Pongo?), short- (apes & apiths) vs long-
legged (only Homo), etc.

- The paper doesn't mention the aquarboreal model & the delta model of
BPism. Unforgivable: ill-informed? Refs below.

They also forgot the generalist model of Niemitz & the wading model of
Kuliukas:
- Carsten Niemitz 2002 "A Theory on the Evolution of Human Bipedalism - Die
amphibische Generalistentheorie" Anthropologischer Anzeiger 60:3-66
- Algis Kuliukas 2002 "Wading for Food: The Driving Force of the Evolution
of Bipedalism?" Nutrition & Health 16:267-289

Quote:
- Yes, as I have argued innumerable times, Pan & Gorilla KWing are parallel
adaptations (ref.11=Dainton+Macho, but esp.Inouye has written several papers
on anatomical & ontogenetic differences between P & H KWing). P & probably
also G KWing postdate the H/P split (+-5 Ma).

- As the authors say, anatomical evidence for BPism can't be used for
defining "hominins" (=Homo+apiths). I've been arguing this for ages (see my
Hum.Evol.papers, refs below). In fact, nothing can be used for defining such
a taxon (whether it's called "hominin" or "hominid" or whatever): it's
paraphyletic: there no unique-derived features that discern Homo+apiths to
the exclusion of the rest, eg,
-- Thick or even superthick enamel (Ouranopith, Sivapith, Griphopith,
Afropith etc.) predates the H/P split (+-5 Ma) & even the hominid/pongid
split (+-15 Ma).
-- Apith-like canines predate the H/P split (eg, Wolfpoff etc.2006 "An Ape
or the Ape: is the Toumaï Cranium TM 266 a Hominid?" PaleoAnthropology:
36-50).
-- Sort-legged BPism predates the H/P split (see above).

Conclusion:
Orangutan "BPism" is derived from an earlier sort of BPism already present
in the hominoid LCA, IOW, it's no model for the origin of human locomotion,
but it can be used for reconstructing the hominoid LCA's locomotion.

IMO the origins of human (obligate) BPism & ape (parttime) BPisms are most
parsimoniously explained by an aquarboreal model, eg, wading on 2 legs &
climbing arms overhead in coastal or flooded or swamp forests swamps, where
+-all Miocene fossils (with the possible exception of Ouranopith // robust
apiths later?) are found, eg, in search for aquatic herbaceous vegetation
(cf.Ndoki gorillas wading in forest swamps), mangrove oysters (capuchins)
etc.

--Marc
http://allserv.rug.ac.be/~mvaneech/Symposium.html
http://groups.yahoo.com/group/AAT

- M.Verhaegen, P-F.Puech & S.Munro 2002 "Aquarboreal ancestors?" Trends in
Ecology & Evolution 17:212-7 (can be found in the AAT files or by googling
"aquarboreal")
- R.Wrangham 2005 "The Delta Hypothesis: hominoid ecology & hominin origins"
in D.Lieberman, R.Smith & J.Kelley eds. "Interpreting the past: essays on
human, primate & mammal evolution in honor of David Pilbeam" Brill
Ac.Publishers Boston: 231-242

http://allserv.rug.ac.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html
- M.Verhaegen 1990 "African ape ancestry" Hum.Evol.5:295-297
- 1992 "Did robust australopithecines partly feed on hard parts of
Gramineae?" Hum.Evol.7:63-64
- 1994 "Australopithecines: ancestors of the African apes?"
Hum.Evol.9:121-139
- 1996 "Morphological distance between australopithecine, human and ape
skulls" Hum.Evol.11:35-41
Back to top
Marc Verhaegen
Posted: Sun Jun 03, 2007 4:52 pm
Guest
An Ape or the Ape: is the Toumaï Cranium TM 266 a Hominid?
PaleoAnthropology: 36-50
MH Wolfpoff, J Hawks, B Senut, M Pickford & J Ahern 2006

The Toumaï cranium TM 266 is the first known from any Late Miocene African
hominoid clade, and is one of the best preserved crania of any Miocene
hominoid. Since its publication there has been debate in the scientific
literature and discussion in the popular press over the assertion that this
cranium is significant because it is the earliest known hominid1. The basis
of the hominid assessment rests on two interpretations of the anatomy: a
hominid-like, small, flat-wearing canine; and, cranial features reflecting
an upright stance and bipedal locomotion. In fact, it is widely reported
that the specimen is an upright hominid biped (Haile-Selassie et al.2004,
Kimbel 2004, Lieberman 2002), although this is yet to be verified by
independent observations and study. The history of paleo-anthropology may be
relevant to this assessment, because there have been similar claims for
other extinct primate species. Here, we evaluate the hypothesis that
Sahelanthropus (the genus TM 266 is attributed to) is a hominid by examining
features of the canine and of the cranial base that are said to reflect
canine reduction and change of function, and upright posture and bipedal
locomotion. These are hominid autapomorphies and their presence or absence
in late Miocene hominoids has fundamental importance for identifying the
hominid clade.
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