Re: Hominid Diet Examined

Marc Verhaegen runs away again:
>
> "Rich Travsky" <" traRvEsky"@hotmMOVEail.com> wrote nothing in message
> news:431BBFB3.1FD2123B@xxxxxxxxxxxxxxxxxx
> > Marc Verhaegen wrote:
> > > "Rich Travsky" <" traRvEsky"@hotmMOVEail.com> wrote in message
> > > news:430EA5D4.3F80331F@xxxxxxxxxxxxxxxxxx
> > >
> > > > > > > Thank you very much, Travsky. This again beautifully confirms
> our
> > > views on apith diets.
> > >
> > > > > As usual, an irrelevant & wrong answer from Travsky:
> > >
> > > > > > You mean OTHERS' views. You do no real work of your own.
> > >
> > > > > I mean OUR, my boy. Marc Verhaegen & Pierre-François Puech 2000.
> > > P-F.Puech was one of the first (remember the Franco-American Hadar
> > > expeditions in the 70s?? ring a bell??) to investigate afarensis enamel
> > > microscopically. Okidoki? got it?
> > >
> > > > But you weren't there. Got it?
> > >
> > > And? Your point?
> >
> > Others' work. Again.
> >
> > > My little boy, when we were writing our paper "Aquarboreal ancestors?",
> we
> > > wrote on this subject "one of us" (=P-F.Puech), but the redaction
> changed
> > > this into "we". Got it?
> >
> > Of course my boy, others' work.
> >
> > > Now, after these evasions of yours, can we come to the essential:
> >
> > No answer.
> >
> > > > > > > From a paper with prof.Puech (one of the very first to
> investigate
> > > > > afarensis
> > > > > > > enamel electromicroscopically, see refs below):
> > > > > > >
> > > > > > > "Hominid Lifestyle and Diet Reconsidered: Paleo-Environmental
> and
> > > > > > > Comparative Data"
> > > > > > > > > Musée de l'Homme à Paris, BP 191, 30012 Nîmes 4, France
> > > > > > > Human Evolution 15: 151-162
> > > > > > > (the whole paper can be found at
> > > > > > > http://allserv.rug.ac.be/~mvaneech/Verhaegen.html )
> > > > > > > ... Dental studies suggest that whereas gracile
> australopithecines
> > > > > preferred
> > > > > > > softer fruits and vegetables, the robusts' diet included harder
> food
> > > > > items
> > > > > > > (e.g. Robinson, 1954; Du Brul, 1977; Walker, 1981; Puech, 1992;
> > > > > Lee-Thorp et
> > > > > > > al., 1994). Estimates of robust australopithecine bite force
> suggest
> > > > > > > 'low-energy food that had to be processed in great quantities'
> and
> > > food
> > > > > > > objects 'hard and round in shape' (Demes & Creel, 1988). Du Brul
> > > (1977)
> > > > > > > noticed dental isms between the robust australopithecines and
> the
> > > > > > > bamboo-eating giant panda Ailuropoda melanoleuca (broad, high
> and
> > > heavy
> > > > > > > cheekbones, reduced prognathism and front teeth, broad back
> teeth,
> > > > > premolar
> > > > > > > molarisation), as opposed to gracile australopithecines,
> > > respectively
> > > > > > > non-panda bears.
> > > > > > > Papyrus and reed were present in the paleo-environment of the
> later
> > > > > > > australopithecines (e.g. Olduvai, Chesowanja, Kromdraai), and
> > > Cyperaceae
> > > > > and
> > > > > > > Gramineae are part of the diet of living African hominoids.
> Gorillas
> > > eat
> > > > > > > sedges and bamboo shoots and stalks, gorillas and chimpanzees
> eat
> > > cane,
> > > > > > > chimps and humans eat water lilies, and rice and other cereals
> are
> > > > > staple
> > > > > > > food for humans. Supplementing their diet with parts of
> grasslike
> > > plants
> > > > > > > might have been enabled the robusts to bridge the dry season,
> when
> > > > > fruits
> > > > > > > and soft vegetables were scarce.
> > > > > > > Studies of dental enamel microwear provide other details. In the
> > > early
> > > > > > > australopithecines of Garusi-Laetoli and Hadar (A. afarensis 4-3
> Myr
> > > > > BP),
> > > > > > > the cheekteeth enamel has a polished surface and the microwear
> looks
> > > > > like
> > > > > > > that of the capybara Hydrochoerus hydrochaeris and that of the
> > > mountain
> > > > > > > beaver Aplodontia rufa (Puech et al., 1986). These animals are
> > > > > semi-aquatic
> > > > > > > rodents that feed mainly on sappy marsh and riverside herbs,
> grasses
> > > and
> > > > > > > bark of young trees. It has recently become clear that Western
> > > lowland
> > > > > > > gorillas G. g. gorilla spend some time eating aquatic herbaceous
> > > > > vegetation
> > > > > > > (AHV) like Hydrocharitaceae herbs and Cyperaceae sedges (Doran &
> > > > > McNeilage,
> > > > > > > 1997).
> > > > > > > Comparisons of molar enamel in South African fossils show that
> A.
> > > > > robustus
> > > > > > > ate substantially more hard food items than A. africanus (Grine
> &
> > > Kay,
> > > > > > > 1988). Incisal microwear suggests that A. robustus may have
> ingested
> > > > > foods
> > > > > > > that required less extensive incisal preparation than the foods
> > > consumed
> > > > > by
> > > > > > > A. africanus, such as fruits (Ungar & Grine, 1991), and
> 'incisors
> > > need
> > > > > not
> > > > > > > be employed in the manipulation of hard objects' (Ungar & Grine,
> > > 1989).
> > > > > > > The enamel of the East African robusts (Olduvai and Peninj)
> displays
> > > > > more
> > > > > > > pits, wide parallel striations and deep recessed dentine,
> resembling
> > > > > that of
> > > > > > > the beaver Castor fiber, that eats riverine and riverside herbs,
> > > roots
> > > > > of
> > > > > > > water lilies, bark and woody plants in a temperate climate.
> 'Many
> > > food
> > > > > > > plants growing in marsh land and indeed many grasses, have high
> > > > > > > concentrations of siliceous particles known as opal phytoliths.
> The
> > > > > > > consumption of such foods produces a great deal of wear, and the
> > > enamel
> > > > > and
> > > > > > > dentine have a blunted appearance. Ancient Egyptians ate papyrus
> > > shoots
> > > > > > > (Puech et al., 1983b) and we suppose that [O.H.16] did the same
> with
> > > > > swamp
> > > > > > > margin plants' (Puech, 1992). Whereas the East African robusts
> seem
> > > to
> > > > > have
> > > > > > > had aquatic plants and papyrus shoots in their diet and ate more
> > > woody
> > > > > > > plants than the earlier australopithecines, habilis O.H.16
> > > apparently
> > > > > > > supplemented the AHV of the earlier australopithecines with acid
> > > fruits
> > > > > > > (Puech, 1984). In the habilis cheekteeth, the margins of the
> striae
> > > have
> > > > > > > been polished and slightly etched, resembling the microwear of
> the
> > > coypu
> > > > > > > Myocastor coypus. This rodent feeds on reed, sedges, marsh
> plants,
> > > > > fruits
> > > > > > > and molluscs in river and lake margins. It thus seems that an
> early
> > > > > > > australopithecine diet of fruits (larger front teeth) and AHV
> > > > > (polishing)
> > > > > > > was supplemented with unripe fruits (acid etching) in habilis,
> and
> > > with
> > > > > > > woody plants in the robusts (more wear).
> > > > > > > The suggestion of Walker (1981) that A. boisei KNM-ER 406 and
> 729
> > > were
> > > > > > > bulk-eaters of whole fruits, 'small, hard fruits with casings,
> pulp,
> > > > > seeds
> > > > > > > and all', could explain the deep recessed occlusal dentine, but
> not
> > > the
> > > > > > > glossy appearance of heavily polished enamel, which is more
> typical
> > > for
> > > > > > > marsh plant feeders. In terrestrial grazers such as sheep, tooth
> > > wear is
> > > > > > > faster, with a different gradient and fabric-like grooves.
> > > > > > > These microwear data are consistent with the strontium/calcium
> > > ratios in
> > > > > > > Swartkrans fossils (Sillen, 1992). Apart from partial carnivory
> > > (rather
> > > > > > > unlikely with the robusts' dentition, see Du Brul, 1977; Walker,
> > > 1981),
> > > > > > > Sillen provides two possible explanations for the low Sr/Ca of
> A.
> > > > > robustus:
> > > > > > > eating leaves and shoots of forbs and woody plants (kudu diet),
> and
> > > > > eating
> > > > > > > food derived from a wet microhabitat, for instance, from
> > > well-drained
> > > > > > > streamside soils.
> > > > > > > In our opinion, the coincidence of several independent lines of
> > > evidence
> > > > > > > (paleo-milieu, dental morphology, enamel microwear, Sr/Ca
> ratios)
> > > leaves
> > > > > > > little doubt that some or all australopithecines fed regularly
> on
> > > AHV
> > > > > > > growing in shallow waters, much more than Western gorillas do
> today
> > > > > > > (Chadwik, 1995; Doran & McNeilage, 1997). It is conceivable that
> > > hominid
> > > > > > > bipedality first arose in the shallow waters of gallery or
> mangrove
> > > or
> > > > > swamp
> > > > > > > forests. 'One of the strong points about the aquatic theory is
> in
> > > > > explaining
> > > > > > > the origin of bipedality. If our ancestors did go into the
> water,
> > > that
> > > > > would
> > > > > > > forced them to walk upright' (Stringer, 1997). That a gradual
> > > > > evolutionary
> > > > > > > transition from forest to marshland is possible is illustrated
> by
> > > the
> > > > > > > Western lowland gorillas that spend some time feeding on AHV,
> wading
> > > > > > > bipedally, sitting and playing in marshy forest clearings
> (Chadwik,
> > > > > 1995;
> > > > > > > Doran & McNeilage, 1997; NDR TV film, 1997).
> > > > > > >
> > > > > > > :-)
> > > > > > >
> > > > > > > Marc Verhaegen
> > > > > > >
> > > > > > > http://www.onelist.com/community/AAT
> > > > > > >
> > > > > > > _______
> > > > > > >
> > > > > > > "Rich Travsky" <traRvEsky@xxxxxxxxxxxxxxx> wrote in message
> > > > > > > news:42F39C78.2AFB1864@xxxxxxxxxxxxxxxxxx
> > > > > > > > Sez it's supposed to be in the Aug 4th Nature, but nothing on
> line
> > > > > yet...
> > > > > > > >
> > > > > > > >
> > > > > > > > http://live.psu.edu/story/12922
> > > > > > > >
> > > > > > > > University Park, Pa. -- A Penn State researcher is part of
> the
> > > team
> > > > > that
> > > > > > > > developed techniques that have generated insights into
> dietary
> > > > > > > divergences
> > > > > > > > between some of our human ancestors, allowing scientists to
> > > better
> > > > > > > > understand the evolutionary path that led to the modern-day
> diets
> > > > > that
> > > > > > > > humans consume.
> > > > > > > >
> > > > > > > > "Our new techniques are allowing us to get beyond simple
> > > dichotomies
> > > > > and
> > > > > > > > helping us understand the processes by which dietary
> evolution is
> > > > > > > > working," said Peter Ungar, professor of anthropology at the
> > > > > University
> > > > > > > > of Arkansas.
> > > > > > > >
> > > > > > > > Ungar and Robert Scott, postdoctoral fellow at the University
> of
> > > > > > > Arkansas,
> > > > > > > > with colleagues at the Worcester Polytechnic Institute, State
> > > > > University
> > > > > > > > of New York at Stony Brook, Johns Hopkins University School
> of
> > > > > Medicine
> > > > > > > > and Penn State, report their findings in the August 4 issue
> of
> > > the
> > > > > > > journal
> > > > > > > > Nature.
> > > > > > > >
> > > > > > > > The researchers, including Alan Walker, Evan Pugh professor
> of
> > > > > biological
> > > > > > > > anthropology and biology at Penn State, investigated
> microscopic
> > > wear
> > > > > on
> > > > > > > > the teeth of two species of ancient hominims --
> Australopithecus
> > > > > > > africanus,
> > > > > > > > which lived between 3.3 million and 2.3 million years ago,
> and
> > > > > > > Paranthropus
> > > > > > > > robustus, which lived between 2 million and 1.5 million years
> > > ago.
> > > > > The
> > > > > > > pits
> > > > > > > > and scratches found on the teeth offer a visual history of
> the
> > > type
> > > > > of
> > > > > > > food
> > > > > > > > consumed by the tooth's owner. Pits indicate a diet of hard,
> > > brittle
> > > > > > > foods,
> > > > > > > > like nuts and seeds, while scratches imply a diet of tough
> foods,
> > > > > like
> > > > > > > > leaves and possibly meat.
> > > > > > > >
> > > > > > > > Traditional examinations of these ancient teeth -- counting
> pits
> > > and
> > > > > > > lines
> > > > > > > > on a black and white electron micrograph image -- suggested
> that
> > > A.
> > > > > > > > africanus ate tough foods and P. robustus dined on hard,
> brittle
> > > > > fare.
> > > > > > > > However, the researchers used a new technique developed by
> Ungar
> > > and
> > > > > his
> > > > > > > > colleagues that combines engineering software,
> scale-sensitive
> > > > > fractal
> > > > > > > > analysis and a scanning confocal microscope to create a
> > > reproducible
> > > > > > > texture
> > > > > > > > analysis for teeth -- and the analysis tells a more complete
> > > story.
> > > > > The
> > > > > > > > researchers looked at both roughness, or complexity, and
> > > > > directionality
> > > > > > > in
> > > > > > > > the teeth they examined.
> > > > > > > >
> > > > > > > > "Since food objects interact with teeth, we have different
> kinds
> > > of
> > > > > > > > complexity in different diets. Directionality also correlates
> > > with
> > > > > diet,"
> > > > > > > > Scott said. Hard foods like nuts and seeds tend to lead to
> more
> > > > > complex
> > > > > > > tooth
> > > > > > > > profiles, while tough foods like leaves lead to more
> scratches,
> > > which
> > > > > > > > corresponds with directionality.
> > > > > > > > ...
> > > > > > > > The analysis showed that the two species had significant
> amounts
> > > of
> > > > > > > overlap in
> > > > > > > > their diets and that while P. robustus had more complexity in
> its
> > > > > tooth
> > > > > > > wear,
> > > > > > > > indicating that it ate more hard and brittle foods than A.
> > > africanus,
> > > > > it
> > > > > > > ate
> > > > > > > > tough foods as well.
> > > > > > > >
> > > > > > > > The researchers believe that this indicates that the species
> > > > > frequently
> > > > > > > ate the
> > > > > > > > same types of foods, but that in times of scarcity or
> seasonal
> > > > > changes,
> > > > > > > P.
> > > > > > > > robustus changed its diet to include foods that differed from
> > > those
> > > > > of A.
> > > > > > > > africanus.
> > > > > > > >
> > > > > > > > "The difference in their evolution in terms of diet is not
> driven
> > > by
> > > > > > > their
> > > > > > > > preferences, but by scarcity," Ungar said. "It gives you a
> whole
> > > new
> > > > > way
> > > > > > > of
> > > > > > > > thinking about dietary adaptation."
> > > > > > > > ...
> > > > > > > >
> > > > > > > >
> > > > > > > > scarcity...
.

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