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| Gerrit Hanenburg... |
 Posted: Sat Oct 10, 2009 3:55 am |
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Guest
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One week after the publication we've been waiting for for 15 years
this group is awfully silent on Ardipithecus, while it should be abuzz
about its implications. Have we become so numb by years of acrimonious
debate about AAT and such? Such a shame.
Anyway, some implications of Ardipithecus:
- Death of the chimpanzee referential model. The chimpanzee is not a
living fossil but is derived in several aspects, and the CLCA was not
a chimpanzee. Early hominids did not compete with chimpanzees.
- Death of the savanna model with regard to the origin of bipedalism.
However, the habitat of Ardipithecus is reconstructed as woodland.
Woodland is already an environmental grade between closed-canopy
forest and more open environments. The Aramis environment does have a
grassy component and the isotopic data from Ardipithecus teeth signals
a C4 component of the diet between 10-25%.
More open environments are still proposed for the later adaptive
plateaus of Australopithecus and Homo.
- Four adaptive plateaus are now distinguished with regard to hominid
origins and subsequent evolution:
1) CLCA (last common ancestor of chimpanzees and humans; palmigrade
arborealist, dimorphic canines, forest frugivore/omnivore).
2) Ardipithecus (partially arboreal, facultative biped, feminized
canine, woodland omnivore). This adaptive plateau is newly proposed.
3) Australopithecus (striding terrestrial biped, postcanine
megadontia, Pan-African, wide niche).
4) Homo (enlarged brain, dentognathic reduction, technology reliant,
Old World range).
- Ardipithecus is on the hominid branch of the phylogenetic tree. It
shares several derived craniodental and postcranial characters with
later hominids (e.g. advanced cranial base flexion, anterior position
of basion).
- Ardipithecus represents an adaptive plateau with bipedality on the
ground but also retaining significant arboreal capability. If
Sahelanthropus also belongs here the implication is that this
"compromise" arboreal/terrestrial adaptive plateau lasted for several
million years (c. 7 mya - 4.4 mya).
Gerrit |
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| Lee Olsen... |
| Posted: Sat Oct 10, 2009 6:33 am |
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Guest
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On Oct 10, 7:46 am, Marc Verhaegen <m_verhae... at (no spam) skynet.be> wrote:
[quote:51c9ac4b11]Hanenburg :
One week after the publication we've been waiting for for 15 years
this group is awfully silent on Ardipithecus, while it should be abuzz
about its implications. Have we become so numb by years of acrimonious
debate about AAT and such? Such a shame.
Yes, a real shame, but there's +-nobody left at s.a.p: only a few kudu
runners & some creationists who apparently like to discuss things with each
other...
[/quote:51c9ac4b11]
Nobody + one wet ape lunatic.
[quote:51c9ac4b11]
Hanenburg's interpretations mostly repeat the fossil-hunters'
anthropocentrisms:
Anyway, some implications of Ardipithecus:
- Death of the chimpanzee referential model. The chimpanzee is not a
living fossil but is derived in several aspects, and the CLCA was not
a chimpanzee.
Yes, that's what I said already 20 years ago in my Human Evolution papershttp://users.ugent.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html
[/quote:51c9ac4b11]
Trying to take credit where it isn't due again? You simply copied
others, and
like them, failed miserably---that's why nobody credible cites your
work.
<snip rubbish>
[quote:51c9ac4b11]
In fact, the savanna model is dead with regard to *everything*.
[/quote:51c9ac4b11]
Only dead to brain-dead wetape lunatics.
<snip rest of delusional wet-ape nonsense> |
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| Lee Olsen... |
| Posted: Sat Oct 10, 2009 6:43 am |
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On Oct 10, 7:46 am, Marc Verhaegen <m_verhae... at (no spam) skynet.be> wrote:
[quote:d20a42170d]Yes, a real shame, but there's +-nobody left at s.a.p: only a few kudu
runners...
[/quote:d20a42170d]
Oh yeah, I forgot.... watch and weep, wetloon:
http://www.youtube.com/watch?v=PDwig7LM5y8&NR=1 |
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| Marc Verhaegen... |
| Posted: Sat Oct 10, 2009 8:46 am |
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Guest
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Hanenburg :
[quote:010c012f5b]One week after the publication we've been waiting for for 15 years
this group is awfully silent on Ardipithecus, while it should be abuzz
about its implications. Have we become so numb by years of acrimonious
debate about AAT and such? Such a shame.
[/quote:010c012f5b]
Yes, a real shame, but there's +-nobody left at s.a.p: only a few kudu
runners & some creationists who apparently like to discuss things with each
other...
:-D
Hanenburg's interpretations mostly repeat the fossil-hunters'
anthropocentrisms:
[quote:010c012f5b]Anyway, some implications of Ardipithecus:
- Death of the chimpanzee referential model. The chimpanzee is not a
living fossil but is derived in several aspects, and the CLCA was not
a chimpanzee.
[/quote:010c012f5b]
Yes, that's what I said already 20 years ago in my Human Evolution papers
http://users.ugent.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html
The H/P LCA had features of humans & of chimps & unique features (mosaic
evolution): rel.thick enamel, +-short canines, apelike brain, no KWing,
rel.short arms & hands (+-human-like), rel.short legs, vertical lumbar
spine, rel.short ilia, broad pelvis & flaring ilia (+ long femoral necks &
valgus knees), etc.
[quote:010c012f5b]Early hominids did not compete with chimpanzees.
[/quote:010c012f5b]
??
Of course: chimps & humans & gorillas are hominids.
But I guess you believe Ardip is a closer relative of H than of P?
Nonsense: it was much too primitive, and besides, the earliest Ardip fossils
predated the H/P split.
[quote:010c012f5b]- Death of the savanna model with regard to the origin of bipedalism.
[/quote:010c012f5b]
That is known for ages, eg, we said that already 25 years ago, eg, in my
Medical Hypotheses papers.
In fact, the savanna model is dead with regard to *everything*.
The Homo fossils that are sometimes found in savannas didn't lay there
because it was savanna, but because some populations followed rivers inland.
[quote:010c012f5b]However, the habitat of Ardipithecus is reconstructed as woodland.
[/quote:010c012f5b]
Yes, ground-water supported grassy woodland. Other Ardip fossils are found
in wetter forests, but the Lower Aramis ones apparently in more open & not
impossibly drier terrain: "swale ... modern ground-water forests such as
Kibwezi ... Evidence for Celtis, Myrica & palm trees fits well with the
presence of a groundwater-supported grassy woodland to forest ... papyrus
.... shallow-water fish: 275 identified Lower Aramis Mbr fish spms incl.175
catfish Clarias (tolerant of highly deoxygenated waters & wide Tp ranges),
20 Barbus, 21 Cichlidae ..."
I guess they lived a bit like lowland gorillas today, but in generally more
open landscapes, eating more AHV & possibly more fruits, less climbing, no
KWing, possibly more on the ground, probably more walking/wading (BP?) in
wet ground & shallow waters, perhaps in more open woodland. Possibly, KWing
is less suited to water-saturated ground.
[quote:010c012f5b]Woodland is already an environmental grade between closed-canopy
forest and more open environments.
[/quote:010c012f5b]
"already"?
??
No prejudices, please.
Do you really believe Ardip was evolving into the human direction??
There's nothing human in this Pliocene fossil ape: it had rel.thin enamel,
widely divergent big toes etc. Its so-called human-like features are
primitive for hominids (sensu HPG) & even pongids, eg, a vertical spine is
very likely at least 20 Ma (google, eg, "Filler Morotopith").
[quote:010c012f5b]The Aramis environment does have a
grassy component and the isotopic data from Ardipithecus teeth signals
a C4 component of the diet between 10-25%.
More open environments are still proposed for the later adaptive
plateaus of Australopithecus and Homo.
[/quote:010c012f5b]
Yes, Pleistocene robust apiths in wetlands, lagoons, papyrus swamps etc.,
Homo along seacoast & rivers.
[quote:010c012f5b]- Four adaptive plateaus are now distinguished with regard to hominid
origins and subsequent evolution:
1) CLCA (last common ancestor of chimpanzees and humans; palmigrade
arborealist, dimorphic canines, forest frugivore/omnivore).
[/quote:010c012f5b]
The H/P LCA c 5 Ma had probably rel.short canines (cf.bonobo?).
It was probably not very stronlgy arboreal any more, rather wading-walking
in swamps & swampy ground, but still climbing arms overhead in the branches
above (for safety, sleeping, fruits...).
Palmigrade pronograde? Probably not much: it had a vertical spine (wading?
floating? hanging? &/or sitting?).
But of course not KWing. Finally, the idea that the H/P & HP/G LCAs were
KWers has now been abandoned by +-all PAs.
Frugi-omnivory: likely, perhaps also folivory on AHV & THV.
Probably rel.thick-enameled (eg, palmnuts etc.).
[quote:010c012f5b]2) Ardipithecus (partially arboreal, facultative biped, feminized
canine, woodland omnivore). This adaptive plateau is newly proposed.
[/quote:010c012f5b]
Nonsense. Ardip was more primitive than the H/P LCA in most respects (eg, a
vertical spine is primitive: Morotop).
The Ardip side-branch (? Sahelanthr=(Orrorin?)=Ardip) most likely originated
before the H/P split.
[quote:010c012f5b]3) Australopithecus (striding terrestrial biped, postcanine
megadontia, Pan-African, wide niche).
[/quote:010c012f5b]
Apiths were +-on the way to living Afr.apes: evolving longer arms & hands,
more KWing, longer ilia, longer canines, thinner enamel etc. (P//G).
Apiths were striding? Probably yes, but in swamps & on wet terrain (like
Ardip).
Post-C megadontia for calorie-poor sedges, cane, bamboo, papyrus etc., not
impossibly also for hard-shelled invertebrates (google, eg, "van der Merwe
boisei papyrus" & "durophage Shabel").
Wide niche?
- E.Afr.robusts AHV+TVH, mostly herbivorous.
- S.Afr.robusts more omnivorous probably.
[quote:010c012f5b]4) Homo (enlarged brain, dentognathic reduction, technology reliant,
Old World range).
[/quote:010c012f5b]
Yes, as can be expected in a littoral species that dispersed along coasts &
rivers: aquatic=slippery foods full of PUFAs & DHA, dexterity & tool use for
cracking shells or crayfish & sometimes for butchering stranded whales or
drowned bovids etc.
[quote:010c012f5b]- Ardipithecus is on the hominid branch of the phylogenetic tree. It
shares several derived craniodental and postcranial characters with
later hominids (e.g. advanced cranial base flexion, anterior position
of basion).
[/quote:010c012f5b]
You seem to believe that Ardip is closer to H than to P??
Ridiculous: Miocene hominids-pongids already had vertical spines (eg,
Morotopith).
[quote:010c012f5b]- Ardipithecus represents an adaptive plateau with bipedality on the
ground
[/quote:010c012f5b]
On the bottom of swamps & in wet ground, you mean?
But also climbing in the branches above the wet/woodland/swamps etc.
[quote:010c012f5b]but also retaining significant arboreal capability.
[/quote:010c012f5b]
"retaining" is wishful thinking (not impossibly "re-evolving"), but of
course, Ardip was partly arboreal (although possibly less so than Dryop or
even Oreop).
[quote:010c012f5b]If Sahelanthropus also belongs here the implication is that this
"compromise" arboreal/terrestrial adaptive plateau lasted for several
million years (c. 7 mya - 4.4 mya).
[/quote:010c012f5b]
No compromise, but the basic milieu: the early milieus of hominids-pongids
(18-2 Ma) were swamp/flooded/mangrove/etc.forests/woodlands. They all were
aquarboreal, the different spp radiated into different milieus with a lot of
water & trees, spending some time in the trees, some time on the wet ground,
some time in swamps etc.: some spp more in the trees (eg, Dryop), some more
in the swamps (eg, Oreop?), some more on the ground in wetlands (eg,
Ouranop, robust apiths) or woodlands (eg, Ardip?), some feeding on AHV-THV
(eg, Ardip, gorilla), some more on fruits or nuts, etc.
Ardip is reminiscent of Oreop in some instances, eg, thinner enamel, widely
divergent hallux, but Oreop (the so-called "swamp ape") was apparently more
arboreal (eg, narrow & long hands & arms).
Google "aquarboreal".
http://users.ugent.be/%7Emvaneech/Verhaegen%20et%20al.%202007.%20Econiche%20
of%20Homo.pdf |
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| Lee Olsen... |
| Posted: Sat Oct 10, 2009 8:48 am |
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Guest
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On Oct 10, 11:11 am, Gerrit Hanenburg
<g.hanenb... at (no spam) inter.nl.nomail.net> wrote:
[quote:7572800548]Lee Olsen <paleoc... at (no spam) hotmail.com> wrote:
Yes, a real shame, but there's +-nobody left at s.a.p: only a few kudu
runners...
Oh yeah, I forgot.... watch and weep, wetloon:
http://www.youtube.com/watch?v=PDwig7LM5y8&NR=1
Spectacular.
See also:http://www.youtube.com/watch?v=fkN6C1ur1t8&NR=1
But this is definitely cooperative hunting.
Gerrit
[/quote:7572800548]
Yes, saw that one too, it was posted recently on the PaleoPlanet
forum.
I posted the short version because I didn't think Marc's attention
span would
last through the longer one :-)
IIRC, there is a Middle Stone Age point in the skull of a buffalo,
in Africa. Then there are the Lower spears at Schöningen. Yep, co-op
hunting
has been around a long time. |
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| Gerrit Hanenburg... |
| Posted: Sat Oct 10, 2009 12:11 pm |
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| RichTravsky... |
| Posted: Sun Oct 11, 2009 11:12 pm |
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Gerrit Hanenburg wrote:
[quote:99f76d9f92]
One week after the publication we've been waiting for for 15 years
this group is awfully silent on Ardipithecus, while it should be abuzz
about its implications. Have we become so numb by years of acrimonious
debate about AAT and such? Such a shame.
[/quote:99f76d9f92]
I don't know if everyone has access to the pdfs. Have they been made available
off the science site?
[quote:99f76d9f92]Anyway, some implications of Ardipithecus:
- Death of the chimpanzee referential model. The chimpanzee is not a
living fossil but is derived in several aspects, and the CLCA was not
a chimpanzee. Early hominids did not compete with chimpanzees.
[/quote:99f76d9f92]
The close genetic match, tho, means it's viable in other ways. Behaviorially
certainly.
[quote:99f76d9f92]- Death of the savanna model with regard to the origin of bipedalism.
However, the habitat of Ardipithecus is reconstructed as woodland.
Woodland is already an environmental grade between closed-canopy
forest and more open environments. The Aramis environment does have a
grassy component and the isotopic data from Ardipithecus teeth signals
a C4 component of the diet between 10-25%.
More open environments are still proposed for the later adaptive
plateaus of Australopithecus and Homo.
[/quote:99f76d9f92]
"savanna" per se has often obscured a more salient characteristic, that is,
openness.
Rarer species in the Ardipithecus-bearing
assemblages indicate that more xeric and open
savanna woodlands were regionally present.
Woodland ground layer always includes heliophilous
(sun-loving, C4) grasses, herbs/forbs,
and incomplete small tree and shrub understories.
Plus some interesting bits in "Geological, Isotopic, Botanical,
Invertebrate, and Lower Vertebrate Surroundings".
Which to me all suggests that a degree of openness (and not open grassland)
is quite the catalyst.
[quote:99f76d9f92][...]
- Ardipithecus is on the hominid branch of the phylogenetic tree. It
shares several derived craniodental and postcranial characters with
later hominids (e.g. advanced cranial base flexion, anterior position
of basion).
[/quote:99f76d9f92]
I'd have to say it's always seemed to me ardipithecus was considered a hominid.
[quote:99f76d9f92]- Ardipithecus represents an adaptive plateau with bipedality on the
ground but also retaining significant arboreal capability. If
Sahelanthropus also belongs here the implication is that this
"compromise" arboreal/terrestrial adaptive plateau lasted for several
million years (c. 7 mya - 4.4 mya).
[/quote:99f76d9f92]
The bipedalism-started-in-the-trees group no doubt feels some justification. |
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| deowll... |
| Posted: Sun Oct 11, 2009 11:45 pm |
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"RichTravsky" <traRvEsky at (no spam) hotmMOVEail.com> wrote in message
news:4AD2BAAF.BCCEA357 at (no spam) hotmMOVEail.com...
[quote:2fe85bf02d]Gerrit Hanenburg wrote:
One week after the publication we've been waiting for for 15 years
this group is awfully silent on Ardipithecus, while it should be abuzz
about its implications. Have we become so numb by years of acrimonious
debate about AAT and such? Such a shame.
I don't know if everyone has access to the pdfs. Have they been made
available
off the science site?
Anyway, some implications of Ardipithecus:
- Death of the chimpanzee referential model. The chimpanzee is not a
living fossil but is derived in several aspects, and the CLCA was not
a chimpanzee. Early hominids did not compete with chimpanzees.
The close genetic match, tho, means it's viable in other ways.
Behaviorially
certainly.
- Death of the savanna model with regard to the origin of bipedalism.
However, the habitat of Ardipithecus is reconstructed as woodland.
Woodland is already an environmental grade between closed-canopy
forest and more open environments. The Aramis environment does have a
grassy component and the isotopic data from Ardipithecus teeth signals
a C4 component of the diet between 10-25%.
More open environments are still proposed for the later adaptive
plateaus of Australopithecus and Homo.
"savanna" per se has often obscured a more salient characteristic, that
is,
openness.
Rarer species in the Ardipithecus-bearing
assemblages indicate that more xeric and open
savanna woodlands were regionally present.
Woodland ground layer always includes heliophilous
(sun-loving, C4) grasses, herbs/forbs,
and incomplete small tree and shrub understories.
Plus some interesting bits in "Geological, Isotopic, Botanical,
Invertebrate, and Lower Vertebrate Surroundings".
Which to me all suggests that a degree of openness (and not open
grassland)
is quite the catalyst.
[...]
- Ardipithecus is on the hominid branch of the phylogenetic tree. It
shares several derived craniodental and postcranial characters with
later hominids (e.g. advanced cranial base flexion, anterior position
of basion).
I'd have to say it's always seemed to me ardipithecus was considered a
hominid.
- Ardipithecus represents an adaptive plateau with bipedality on the
ground but also retaining significant arboreal capability. If
Sahelanthropus also belongs here the implication is that this
"compromise" arboreal/terrestrial adaptive plateau lasted for several
million years (c. 7 mya - 4.4 mya).
The bipedalism-started-in-the-trees group no doubt feels some
justification.
[/quote:2fe85bf02d]
The gibbon is a bipid. It is also small. It will be interesting to find out
how small the founders were.
If this is a wide spread species it may not be clear yet how far into open
territory these beings may have ventured.
I would also note that wide spread and highly varied population of different
ape species existed at this time and we've seen one. |
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| mclark... |
| Posted: Mon Oct 12, 2009 3:38 am |
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On Oct 12, 12:12 am, RichTravsky <traRvE... at (no spam) hotmMOVEail.com> wrote:
[quote:b88f416dd2]Gerrit Hanenburg wrote:
One week after the publication we've been waiting for for 15 years
this group is awfully silent on Ardipithecus, while it should be abuzz
about its implications. Have we become so numb by years of acrimonious
debate about AAT and such? Such a shame.
I don't know if everyone has access to the pdfs. Have they been made available
off the science site?
[/quote:b88f416dd2]
They are available here: http://www.sciencemag.org/ardipithecus/
Non members merely have to register (free and easy).
[snip]
[quote:b88f416dd2]The bipedalism-started-in-the-trees group no doubt feels some justification.
[/quote:b88f416dd2]
Whooo Hoooo!!!!!!!  |
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| Gerrit Hanenburg... |
| Posted: Mon Oct 12, 2009 6:18 am |
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Guest
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RichTravsky <traRvEsky at (no spam) hotmMOVEail.com> wrote:
[quote:98b1d43a32]Gerrit Hanenburg wrote:
One week after the publication we've been waiting for for 15 years
this group is awfully silent on Ardipithecus, while it should be abuzz
about its implications. Have we become so numb by years of acrimonious
debate about AAT and such? Such a shame.
I don't know if everyone has access to the pdfs. Have they been made available
off the science site?
[/quote:98b1d43a32]
They are available without charge from the Science site after a simple
registration.
[quote:98b1d43a32]Anyway, some implications of Ardipithecus:
- Death of the chimpanzee referential model. The chimpanzee is not a
living fossil but is derived in several aspects, and the CLCA was not
a chimpanzee. Early hominids did not compete with chimpanzees.
The close genetic match, tho, means it's viable in other ways. Behaviorially
certainly.
[/quote:98b1d43a32]
But with the proviso that Pan is does not represent an unmodified
primitive condition. Evolution continued on both branches.
[quote:98b1d43a32]- Death of the savanna model with regard to the origin of bipedalism.
However, the habitat of Ardipithecus is reconstructed as woodland.
Woodland is already an environmental grade between closed-canopy
forest and more open environments. The Aramis environment does have a
grassy component and the isotopic data from Ardipithecus teeth signals
a C4 component of the diet between 10-25%.
More open environments are still proposed for the later adaptive
plateaus of Australopithecus and Homo.
"savanna" per se has often obscured a more salient characteristic, that is,
openness.
[/quote:98b1d43a32]
The defining feature is a continuous grassy stratum. The spectrum runs
from wooded to treeless, but canopy cover allways less than 100%.
[quote:98b1d43a32]Rarer species in the Ardipithecus-bearing
assemblages indicate that more xeric and open
savanna woodlands were regionally present.
[/quote:98b1d43a32]
In particular micromammals such as Xerus, Tatera (gerbil), Acomys,
Saidomys, and Arvicanthis indicate more arid conditions nearby.
Also the paucity of aquatic birds (only 3.8% of identified avian
specimens) and water-frequenting reduncine bovids (only 0.3% of
identified large mammals) and hippo's (1.7%) indicate that the
environment was not particularly wet.
[quote:98b1d43a32]Woodland ground layer always includes heliophilous
(sun-loving, C4) grasses, herbs/forbs,
and incomplete small tree and shrub understories.
Plus some interesting bits in "Geological, Isotopic, Botanical,
Invertebrate, and Lower Vertebrate Surroundings".
Which to me all suggests that a degree of openness (and not open grassland)
is quite the catalyst.
[/quote:98b1d43a32]
In particular the information that within this 9 km transect of the
Central Awash Complex (CAC) there is a transition to more open and
arid conditions at SAG-VP-7 and beyond (open grassland with maximum
tree cover less than 40%).
[quote:98b1d43a32][...]
- Ardipithecus is on the hominid branch of the phylogenetic tree. It
shares several derived craniodental and postcranial characters with
later hominids (e.g. advanced cranial base flexion, anterior position
of basion).
I'd have to say it's always seemed to me ardipithecus was considered a hominid.
[/quote:98b1d43a32]
And the phylogentic analysis is there to prove it.
[quote:98b1d43a32]- Ardipithecus represents an adaptive plateau with bipedality on the
ground but also retaining significant arboreal capability. If
Sahelanthropus also belongs here the implication is that this
"compromise" arboreal/terrestrial adaptive plateau lasted for several
million years (c. 7 mya - 4.4 mya).
The bipedalism-started-in-the-trees group no doubt feels some justification.
[/quote:98b1d43a32]
And when descending to the ground these protohominids were already
better adapted to bipedalism than the modern KW's (e.g. long, flexible
lumbar spine (facultative lordosis), superoinferior abbreviation of
the iliac isthmus (shorter pelvis)).
Gerrit |
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| rwalker... |
| Posted: Mon Oct 12, 2009 7:35 am |
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Guest
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On Sun, 11 Oct 2009 23:12:15 -0600, RichTravsky
<traRvEsky at (no spam) hotmMOVEail.com> wrote:
[quote:71616bc9b0]Gerrit Hanenburg wrote:
One week after the publication we've been waiting for for 15 years
this group is awfully silent on Ardipithecus, while it should be abuzz
about its implications. Have we become so numb by years of acrimonious
debate about AAT and such? Such a shame.
I don't know if everyone has access to the pdfs. Have they been made available
off the science site?
[/quote:71616bc9b0]
They are available for free on the SCIENCE web site with a free
registration. |
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| Lee Olsen... |
| Posted: Mon Oct 12, 2009 7:50 am |
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Guest
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On Oct 10, 2:55 am, Gerrit Hanenburg <g.hanenb... at (no spam) inter.nl.nomail.net>
wrote:
<snip>
[quote:dd5fc2714c]
Anyway, some implications of Ardipithecus:
- Death of the chimpanzee referential model. The chimpanzee is not a
living fossil but is derived in several aspects, and the CLCA was not
a chimpanzee. Early hominids did not compete with chimpanzees.
[/quote:dd5fc2714c]
Great, I was getting tired of walking around on my hands.
[quote:dd5fc2714c]
- Death of the savanna model with regard to the origin of bipedalism.
[/quote:dd5fc2714c]
Ardi confirms the savanna model, not kills it.
The difference, I think, is in just how simplistic one wants to
go in defining the term bipedalism. Obviously it was a series
of incremental steps that were acting like neutral alleles, that
were only acted upon when some environmental factor (or other factor)
kicked in.
The only thing dead about the early savanna model (for some early
workers
anyway) was the idea of a modern Homo-sized brain preceding
bipedalism,
thus fueling ideas like the Piltdown hoax.
[quote:dd5fc2714c]However, the habitat of Ardipithecus is reconstructed as woodland.
Woodland is already an environmental grade between closed-canopy
forest and more open environments. The Aramis environment does have a
grassy component and the isotopic data from Ardipithecus teeth signals
a C4 component of the diet between 10-25%.
More open environments are still proposed for the later adaptive
plateaus of Australopithecus and Homo.
[/quote:dd5fc2714c]
Yep, just as expected from the early savanna model, people like Dart:
http://johnhawks.net/weblog/topics/humor/quotes/dart_savanna_model_2007.html
or
http://tinyurl.com/ykkjo6e
Now, it is easy for us to be critical of Dart's timeline with all the
modern
dating tech, he had no choice in thinking in terms of 10,000s or
100,000s
of years when the process was actually in the millions, so naturally
he got some of the process skewed.
[quote:dd5fc2714c]
- Four adaptive plateaus are now distinguished with regard to hominid
origins and subsequent evolution:
1) CLCA (last common ancestor of chimpanzees and humans; palmigrade
arborealist, dimorphic canines, forest frugivore/omnivore).
2) Ardipithecus (partially arboreal, facultative biped, feminized
canine, woodland omnivore). This adaptive plateau is newly proposed.
3) Australopithecus (striding terrestrial biped, postcanine
megadontia, Pan-African, wide niche).
4) Homo (enlarged brain, dentognathic reduction, technology reliant,
Old World range).
[/quote:dd5fc2714c]
What we can't see is in-between the lines, although the C4 % in Ardi's
teeth is a clue. Just because a creature (when N=s few) is found
in a certain habitat doesn't mean that's where it evolved, it only
means
that's a place it could adapt to and could be biased by the presents
of the
amount of water to fossilize in. It is only when stone tools show up
that one can see how much bias there is, since stone tools don't need
water in order to be preserved. The pattern of distribution is not
always
the same as where the greatest % of fossils are found.
[quote:dd5fc2714c]
- Ardipithecus is on the hominid branch of the phylogenetic tree. It
shares several derived craniodental and postcranial characters with
later hominids (e.g. advanced cranial base flexion, anterior position
of basion).
- Ardipithecus represents an adaptive plateau with bipedality on the
ground but also retaining significant arboreal capability.
[/quote:dd5fc2714c]
Yeah, looks like Sir Authur Kieth called it correctly (least I think
it was him).
Gibbons would make the best comparision as to what our bipedal
ancestor
looked like.
http://www.youtube.com/watch?v=hlzRCHASvsw
[quote:dd5fc2714c]If
Sahelanthropus also belongs here the implication is that this
"compromise" arboreal/terrestrial adaptive plateau lasted for several
million years (c. 7 mya - 4.4 mya).
Gerrit[/quote:dd5fc2714c] |
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| Lee Olsen... |
| Posted: Mon Oct 12, 2009 9:22 am |
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On Oct 12, 11:41 am, "deowll" <deo... at (no spam) gmail.com> wrote:
[quote:28074ba24b]
Or maybe an orangutan?
[/quote:28074ba24b]
Why not, as Gerrit pointed out, anything at this point is better than
what the chimps ("referential model") are doing. Orangs, gibbons,
a few of the lemurs, and us are in right now.... gorillas and chimps
look like the odd-men out. |
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| deowll... |
| Posted: Mon Oct 12, 2009 9:58 am |
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Guest
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"Gerrit Hanenburg" <g.hanenburg at (no spam) inter.nl.nomail.net> wrote in message
news:ak76d5tm1s0abptm6li6hclrqa8bo2po5f at (no spam) 4ax.com...
[quote:0ebc1b99e2]RichTravsky <traRvEsky at (no spam) hotmMOVEail.com> wrote:
Gerrit Hanenburg wrote:
One week after the publication we've been waiting for for 15 years
this group is awfully silent on Ardipithecus, while it should be abuzz
about its implications. Have we become so numb by years of acrimonious
debate about AAT and such? Such a shame.
I don't know if everyone has access to the pdfs. Have they been made
available
off the science site?
They are available without charge from the Science site after a simple
registration.
Anyway, some implications of Ardipithecus:
- Death of the chimpanzee referential model. The chimpanzee is not a
living fossil but is derived in several aspects, and the CLCA was not
a chimpanzee. Early hominids did not compete with chimpanzees.
The close genetic match, tho, means it's viable in other ways.
Behaviorially
certainly.
But with the proviso that Pan is does not represent an unmodified
primitive condition. Evolution continued on both branches.
- Death of the savanna model with regard to the origin of bipedalism.
However, the habitat of Ardipithecus is reconstructed as woodland.
Woodland is already an environmental grade between closed-canopy
forest and more open environments. The Aramis environment does have a
grassy component and the isotopic data from Ardipithecus teeth signals
a C4 component of the diet between 10-25%.
More open environments are still proposed for the later adaptive
plateaus of Australopithecus and Homo.
"savanna" per se has often obscured a more salient characteristic, that
is,
openness.
The defining feature is a continuous grassy stratum. The spectrum runs
from wooded to treeless, but canopy cover allways less than 100%.
Rarer species in the Ardipithecus-bearing
assemblages indicate that more xeric and open
savanna woodlands were regionally present.
In particular micromammals such as Xerus, Tatera (gerbil), Acomys,
Saidomys, and Arvicanthis indicate more arid conditions nearby.
Also the paucity of aquatic birds (only 3.8% of identified avian
specimens) and water-frequenting reduncine bovids (only 0.3% of
identified large mammals) and hippo's (1.7%) indicate that the
environment was not particularly wet.
Woodland ground layer always includes heliophilous
(sun-loving, C4) grasses, herbs/forbs,
and incomplete small tree and shrub understories.
Plus some interesting bits in "Geological, Isotopic, Botanical,
Invertebrate, and Lower Vertebrate Surroundings".
Which to me all suggests that a degree of openness (and not open
grassland)
is quite the catalyst.
In particular the information that within this 9 km transect of the
Central Awash Complex (CAC) there is a transition to more open and
arid conditions at SAG-VP-7 and beyond (open grassland with maximum
tree cover less than 40%).
[...]
- Ardipithecus is on the hominid branch of the phylogenetic tree. It
shares several derived craniodental and postcranial characters with
later hominids (e.g. advanced cranial base flexion, anterior position
of basion).
I'd have to say it's always seemed to me ardipithecus was considered a
hominid.
And the phylogentic analysis is there to prove it.
- Ardipithecus represents an adaptive plateau with bipedality on the
ground but also retaining significant arboreal capability. If
Sahelanthropus also belongs here the implication is that this
"compromise" arboreal/terrestrial adaptive plateau lasted for several
million years (c. 7 mya - 4.4 mya).
The bipedalism-started-in-the-trees group no doubt feels some
justification.
And when descending to the ground these protohominids were already
better adapted to bipedalism than the modern KW's (e.g. long, flexible
lumbar spine (facultative lordosis), superoinferior abbreviation of
the iliac isthmus (shorter pelvis)).
Gerrit
[/quote:0ebc1b99e2]
They have done a tremendous amount of work and have given us a wonderful
snapshot of one location at one time and deserve to be praised for doing so
however the lessons of the present needs to be be learned.
Diversity:
We have two species of Gorilla . We have bonabo and the common chimp. The
common chimp has some twigs. The giant chimp exists and seems to be an
inbreeding subspecies and then you have Jacko and at least three others like
him that may represent a now almost extinct subspecies that walked erectic
by choice simply because their ability to fully extend their legs means they
can. The Ardi we know in the form we know it can't be the only ape around at
that time. Some bleep pulled Jacko's teeth but it might be worth learning if
the other one still alive had small canines and if the body of the one that
died still exists to look at its teeth.
Habitat:
The habitat they can detect is clearly true forest with hints of more open
spaces nearby. This proves that Ardi could and did live at such locations.
The problem is if you look at what we know about the common chimp it seems
to be able to live in deep rainforest, forest, broken forest, open forest,
and will even venture into the edge of savannah if the bleeping humans will
just leave it alone. Tool use in chimp groups varies from a claimed no use
for at least one population to populations that could not survive without
them. To assume that Ardi and its kin was less flexible may be extremely
shortsighted. They seem to about the same size as a common chimp and with
about the same brain size. Nothing suggests their behavior would be less
flexible. |
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| deowll... |
| Posted: Mon Oct 12, 2009 12:41 pm |
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Guest
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"Lee Olsen" <paleocity at (no spam) hotmail.com> wrote in message
news:aa402662-c38d-4558-a8eb-8cafc8d76159 at (no spam) x25g2000prf.googlegroups.com...
On Oct 10, 2:55 am, Gerrit Hanenburg <g.hanenb... at (no spam) inter.nl.nomail.net>
wrote:
<snip>
[quote:edb00a5282]
Anyway, some implications of Ardipithecus:
- Death of the chimpanzee referential model. The chimpanzee is not a
living fossil but is derived in several aspects, and the CLCA was not
a chimpanzee. Early hominids did not compete with chimpanzees.
[/quote:edb00a5282]
Great, I was getting tired of walking around on my hands.
[quote:edb00a5282]
- Death of the savanna model with regard to the origin of bipedalism.
[/quote:edb00a5282]
Ardi confirms the savanna model, not kills it.
The difference, I think, is in just how simplistic one wants to
go in defining the term bipedalism. Obviously it was a series
of incremental steps that were acting like neutral alleles, that
were only acted upon when some environmental factor (or other factor)
kicked in.
The only thing dead about the early savanna model (for some early
workers
anyway) was the idea of a modern Homo-sized brain preceding
bipedalism,
thus fueling ideas like the Piltdown hoax.
[quote:edb00a5282]However, the habitat of Ardipithecus is reconstructed as woodland.
Woodland is already an environmental grade between closed-canopy
forest and more open environments. The Aramis environment does have a
grassy component and the isotopic data from Ardipithecus teeth signals
a C4 component of the diet between 10-25%.
More open environments are still proposed for the later adaptive
plateaus of Australopithecus and Homo.
[/quote:edb00a5282]
Yep, just as expected from the early savanna model, people like Dart:
http://johnhawks.net/weblog/topics/humor/quotes/dart_savanna_model_2007.html
or
http://tinyurl.com/ykkjo6e
Now, it is easy for us to be critical of Dart's timeline with all the
modern
dating tech, he had no choice in thinking in terms of 10,000s or
100,000s
of years when the process was actually in the millions, so naturally
he got some of the process skewed.
[quote:edb00a5282]
- Four adaptive plateaus are now distinguished with regard to hominid
origins and subsequent evolution:
1) CLCA (last common ancestor of chimpanzees and humans; palmigrade
arborealist, dimorphic canines, forest frugivore/omnivore).
2) Ardipithecus (partially arboreal, facultative biped, feminized
canine, woodland omnivore). This adaptive plateau is newly proposed.
3) Australopithecus (striding terrestrial biped, postcanine
megadontia, Pan-African, wide niche).
4) Homo (enlarged brain, dentognathic reduction, technology reliant,
Old World range).
[/quote:edb00a5282]
What we can't see is in-between the lines, although the C4 % in Ardi's
teeth is a clue. Just because a creature (when N=s few) is found
in a certain habitat doesn't mean that's where it evolved, it only
means
that's a place it could adapt to and could be biased by the presents
of the
amount of water to fossilize in. It is only when stone tools show up
that one can see how much bias there is, since stone tools don't need
water in order to be preserved. The pattern of distribution is not
always
the same as where the greatest % of fossils are found.
[quote:edb00a5282]
- Ardipithecus is on the hominid branch of the phylogenetic tree. It
shares several derived craniodental and postcranial characters with
later hominids (e.g. advanced cranial base flexion, anterior position
of basion).
- Ardipithecus represents an adaptive plateau with bipedality on the
ground but also retaining significant arboreal capability.
[/quote:edb00a5282]
Yeah, looks like Sir Authur Kieth called it correctly (least I think
it was him).
Gibbons would make the best comparision as to what our bipedal
ancestor
looked like.
http://www.youtube.com/watch?v=hlzRCHASvsw
Or maybe an orangutan? I don't think they compared the arms and hands of
Ardi to this out group because there hasn't been any need to in the past.
Now I think we do need to make the effort. I'm some what suspicous that they
may be confusing tree hanging adaptions for suspsion feeding with something
else.
I've just got through reading that Ardi had "no" adaptions for suspension.
Of course it does have really long really strong arms with really big hands.
I can recall reading in an article on hobbits that Lucy unlike hobbits had
upward pointing shoulder sockets with the later being considered an
adaption for tree hanging which had been lost in hobbits. We don't have that
part from Ardi. I'm pretty sure Ardi could have supported itself with one
arm while picking and eating fruit with the other for a heck of lot longer
than the worlds greatest gymnist.
[quote:edb00a5282]If
Sahelanthropus also belongs here the implication is that this
"compromise" arboreal/terrestrial adaptive plateau lasted for several
million years (c. 7 mya - 4.4 mya).
Gerrit[/quote:edb00a5282] |
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