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Science Forum Index » Anthropology - Paleo Forum » A.boisei microwear
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| Marc Verhaegen |
 Posted: Thu May 01, 2008 4:22 am |
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Thanks a lot for the ref, DD!
Very interesting paper on the first qualitative analysis of boisei microwear
(quotes below), eg, curious differences between robustus & boisei
(paralleling those between chimps & gorillas??).
Note *qualitative* analyses of boisei & Lucy microwear are already 25 years
old, eg, from our TREE paper (google "aquarboreal"):
The microwear of boisei displays more pits, wide parallel striations &
deep-recessed occlusal dentine features than that of afarensis [25,26],
resembling the microwear of beavers Castor fiber (riverine herbs, roots of
water-lilies, bark, woody plants...). Apparently, an early apith diet of
fruits (larger front teeth) & swamp herbs (polishing) was supplemented with
woody plants in the robust apiths (more wear) (but see below: no tough
leaves & stems in the boisei diet? what about bamboo?? --MV). Walker¹s
suggestion that boisei were bulk-eaters of small, hard fruits with casings,
pulp, seeds and all¹ [27] could explain the deep-recessed dentine, but not
the heavily polished enamel that is typical of marsh-plant feeders [24,25].
24 P-F.Puech cs.1986 "Dental microwear features as an indicator for plant
food in early hominids: a preliminary study of enamel" Hum.Evol.1:507515
25 P-F.Puech 1992 "Microwear studies of early African hominid teeth"
Scann.Microsc.6:10838
26 P-F.Puech cs.1983 "Tooth microwear and dietary pattern in early hominids
from Laetoli, Hadar and Olduvai" JHE 12:7219
27 A.Walker 1981 "Diet and teeth dietary hypotheses and human evolution"
Philos.Trans.R.Soc.Lond.B 292:5764
_____
IMO boisei might have consumed aquatic herbaceous vegetation (AHV) &/or
waterside plants, overlapping with the diet of (lowland?) gorillas today.
Not incompatible with this are the recent studies of Alan Shabel (see below
2008) on the possibility of hard-shelled invertebrates in the "robust" diet
(both boisei & robustus, Alan?). Possibly only robustus ate also HSIs,
explaining the absence of hard objects in the boisei diet?? But then: why
the extremely thick enamel in boisei as well as robustus?
We have to explain 2 things (= 2 sorts of foods?):
- boisei vs.gorilla = thick vs.thin enamel: incl.poorer? harder? tougher
diet? bamboo?? sedges?? papyrus?? ... (cf.robustus vs.chimp ??)
- robustus vs.boisei = robustus diet included hard objects? HSIs??
hard-shelled fruits cf.capuchins?? ...
(IMO "Paranthropus" is para-phyletic: boisei & robustus evolved their broad
cheekteeth & smaller front teeth in parallel, possibly aethiopicus>boisei,
africanus>robustus, see below).
______
PS Ungar, FE Grine & MF Teaford 2008
"Dental Microwear and Diet of the Plio-Pleistocene Hominin Paranthropus
boisei"
PLoS ONE 3(4): e2044
doi:10.1371/journal.pone.0002044
.... boisei had enormous, flat, thickly enameled cheek teeth, a robust
cranium & mandible, & inferred massive, powerful chewing muscles :
"Nutcracker Man" = very mechanically challenging foods? ... High microwear
surface texture complexity & anisotropy in extant primates can be ass.x the
consumption of exceptionally hard & tough foods resp.
Here we present the first quantit.analysis of dental microwear for boisei 7
spms examined preserved unobscured ante-mortem molar microwear : rel.low
complexity & anisotropy values : none of the 7 individuals consumed esp.hard
or tough foods in the days before they died. The apparent discrepancy
betw.microwear & funct.anatomy = hominin example of Liem's Paradox (a highly
derived morphology need not reflect a specialized diet)?
....
- primates that consume hard brittle foods tend to have heavily pitted
complex microwear surface textures,
- those that eat tough leaves or stems have more anisotropic surfaces
dominated by long, parallel striations.
.... boisei spms had light microwear, with most showing wear surfaces
dominated by fine striations. None had the large, deep pits expected of a
hard-object specialist or the uniformly large, deep & parallel striations
observed for tough food grazing mammals. Fractal complexity values were
uniformly low with min.variation ; anisotropy values were moderate, both in
range & central tendency
- the distribution of epLsar values for boisei closely matched afri,
- boisei & afri showed no overlap in Asfc (boisei < afri),
- boisei had much lower Asfc values & ranges & higher average epLsar values
& ranges than robustus,
- boisei had lower Asfc values < africanus & robustus, significantly lower
Asfc variance < robustus, higher epLsar variance > robustus.
- none of the boisei individuals examined consumed extremely hard or
extremely tough foods in the days before death. All lacked the extremes of
Asfc evinced by Lophocebus albigena & esp.Cebus apella (hard, brittle
foods),
- boisei molars also lacked the extremes of epLsar seen in
Trachypith.cristata & Alouatta palliata (tough leaves & stems). The boisei
individuals examined evidently avoided such metabolically challenging foods,
at least in the days before death, cons.x Walker : boisei microwear patterns
resemble those of living frugivores, and differ from those of living
grazers, leaf browsers & bone feeders.
Comparisons with the S.Afr.hominins :
- boisei may have consumed foods with similar ranges of toughness as those
eaten by africanus
- robustus did not eat harder & brittler foods than afri
- the patterns for boisei & robustus are very different : robustus likely
ate foods that were on average much harder & less tough : markedly different
diets or foraging strategies
.... the cranio-dental functional morphology of boisei suggests an ability to
generate & dissipate forces ass.x extremely hard or tough foods ; microwear
texture analysis offers no evidence that these hominins regularly did so ...
The resolution of this discordance probably lies in fundamental differences
in the nature of genetic & non-genetic signals for diet:
- adaptive morphology gives important clues as to what an animal is (or was)
was capable of eating,
- microwear reflects what an animal actually did eat at some point during
its lifetime.
While the craniodental features of boisei would have been capable of
generating large forces on small objects, or processing large quantities of
tough, fibrous foods, microwear suggests that the individuals examined did
not do so in the days before death.
- Does the combination of microwear & morphology point to a novel type of
diet difficult to identify given a lack of extant analogs among the
primates? (well possible IMO: there are a lot of non-primate extant
analogs, eg, see studies of P-F.Puech above, A.Shabel below, Lloyd du Brul,
& others --MV)
- Are specimens examined are not representative of the species as a whole?
While the vast majority of specimens in the hypodigm were excluded from this
study because of taphonomic damage, the uniformity of texture patterns for
all 7 useable spms is remarkable, esp.given their separation in time &
geography. It is difficult to imagine that none of these spms would show
complex or highly anisotropic microwear surfaces if the species regularly
consumed extremely hard or tough foods. (indeed --MV)
- Did boisei occasionally consume extremely hard or tough foods, but so
sufficiently rarely that it was not picked up in the microwear of the 7
individuals sampled? This would suggest a model akin to the subsistence
pattern of gorillas that prefer nutrient rich soft fruits but fall back on
less desirable, more difficult to digest stems & leaves at ³crunch times².
If so, bosei would present another example of Liem's Paradox. Robinson &
Wilson wrote : ³some resources are intrinsically easy to use & widely
preferred ; others require specialized phenotypic traits on the part of the
consumer. This asymmetry allows optimally foraging consumers to evolve
phenotypic specializations on non-preferred resources without greatly
compromising their ability to use preferred resources Specialists should
often reject the very resources that they have evolved traits to use².
(rather unlikely IMO --MV)
The differences between boisei & robustus microwear patterns are more
difficult to interpret in this light ; robustus has a microwear pattern
similar to those of Lophocebus albigena & Cebus apella (fall back on hard
brittle foods). A hard-object fallback model for robustus gains support from
recent studies of isotopes, occlusal morphology, living Afr.apes & plant
resources available in the Plio-Pleistocene. If boisei cranio-dental
morphology also reflects fallback exploitation, they likely consumed
extremely hard or tough foods even less frequently than did their
S.Afr.congeners.
_____
AB Shabel 2008 AAPA abstracts
"The paleobiology of the robust australopithecines (Paranthropus): a test of
the durophage model with a morphometric analysis of carnivoran skulls"
....
The "durophage model" reconstructs the robusts as opportunistic consumers of
hard-shelled invertebrates HSIs, eg, molluscs & crabs : the inclusion of
HSIs in the diet can explain the derived cranio-dental features of the
robusts.
Here I analyse 950 skulls from 136 extant sp (80 genera) from Carnivora
incl.85 % of the carnivoran spp from Africa (excl.pinnipeds). This study
includes a geometric morphometric analysis of 15 landmarks visible on the
mandible in buccal view, as well as traditional (linear) measurements of
cranial features related to mastication, & area measurements of the occlusal
surfaces of maxillary teeth. Carnivoran species are assigned to trophic
categories that reflect the physical properties of their typical food items
; discriminant analysis reveals clear shape differences among these trophic
groups.
There is some overlap between the bamboo-eating carnivorans & those that
rely on hard-shelled invertebrates, but when all of the morphological
evidence is considered, it is evident that the craniodental apparatus of
Paranthropus is most similar to that of durophagous carnivorans that consume
HSIs.
____
From our TREE paper:
.... Eating hard-shelled foods (shellfish, nuts) generally requires thick
enamel, which is typically seen in sea otters, capuchin & most living &
fossil hominidspongids (Box 1, Table 2).
Walker wrote that if a mammalogist who knows nothing about hominids were
asked which mammalian molars most resembled those of Australopithecus, the
answer would probably be orang-utan molars. If asked to look outside the
order Primates, the answer would probably be the molars of the sea otter
Enhydra lutra. This species possesses small anterior teeth & large flat
molars with thick enamel¹ [27].
A recent study [34 = P.Ungar cs.2001 "A premilinary study of molar microwear
of early Homo from East and South Africa" AAPA abstracts):
- (H.?A.?) habilis microwear resembled that of chimps (& orang [35]),
- H.ergaster resembled capuchin (more hard or brittle foods),
- neither taxon specialized on raw meat [34,35].
Sea otters, capuchin & chimpanzees all open shells by hammering them with
hard objects. The most dextrous mammals, besides humans, are raccoons,
otters, capuchin & chimps ...
Might explain HSIs in the diet of S.Afr.apiths & Homo (HP vs.G), but not the
thick enamel of boisei? I guess there are no microwear studies on sea otter
molars?
(Note that IMO afarensis-aethiopicus-boisei might have been extinct
relatives of gorillas, and africanus-robustus of chimps, see my
Hum.Evol.papers
http://users.ugent.be/~mvaneech/Fil/Verhaegen_Human_Evolution.html
IOW, aethiop//africanus = boisei//robustus = gorilla//chimp?)
--Marc |
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| Lee Olsen |
| Posted: Thu May 01, 2008 4:22 am |
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On May 1, 2:22 am, Marc Verhaegen <m_verhae...@skynet.be> wrote:
Quote:
From our TREE paper:
... Eating hard-shelled foods (shellfish, nuts) generally requires thick
Don't insult real professionals by calling that OPINION crap a paper.
First these amateurs claim they did an "extensive survey" of the
literature...
Verhaegen et al. (2002) Page 213:
"Our extensive survey of the literature [17]"
(Who is "[17]"? They cite themselves, who else would made such a
claim)
Of course their survey was proven not to be "extensive" at all as
demonstrated
by this totally false statement:
TREE 2002 Page 213-14:
"... capybaras Hydrochoerus hydrochaeris and
mountain-beavers Aplodontia rufa [24]. Both these
semi-aquatic rodents feed mainly on riverside herbs,
grasses and the bark of young trees."
Anyone even remotely familiar with the literature knows mountain
beavers are not
semi-aquatic and any survey, let alone "extensive survery" would find
this.
These amateur incompetents then go on to, "Acknowledgements" (page
216),
thank "four anonymous referees for corrections and discussions" who
didn't know
anymore about biology than the authors themselves or they would have
picked up
on such an obvious error. Talk about incompetence confirmed by more
incompetence,
this is sloppy research at its worst. The four anaonymous referees
proved the
journal TREE uses amateurs to peer review their papers.
MV et al. then go on to claim: "suggests
that most hominids might have dwelt in 'wet' rather
than 'dry' habitats, and this has been confirmed
by recent discoveries [14,18,19]."
A non-extensive "survey" of sloppy work then leads to the conclusion
that
"A.robustus = wading"? This isn't even a good example of spiritual
imagination.
"Garbage in = garbage out" is the most parsimonious conclusion for
this despicable
opinion paper:
M Verhaegen, P-F Puech & S Munro 2002
Aquarboreal ancestors?
Trends in Ecology & Evolution 17:212-7 |
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| Lee Olsen |
| Posted: Thu May 01, 2008 10:59 am |
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On May 1, 12:04 pm, Marc Verhaegen <m_verhae...@skynet.be> wrote:
Quote: From our TREE paper:
... Eating hard-shelled foods (shellfish, nuts) generally requires thick
Don't insult real professionals by calling that OPINION crap a paper.
My little boy,
Still lusting for little boys, eh? Shame on you.
Quote: who is interested in the OPINION of a childish netloon like
you??
You, you keep reading my posts, thanks.
 |
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| Marc Verhaegen |
| Posted: Thu May 01, 2008 2:04 pm |
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Quote: From our TREE paper:
... Eating hard-shelled foods (shellfish, nuts) generally requires thick
Don't insult real professionals by calling that OPINION crap a paper.
My little boy, who is interested in the OPINION of a childish netloon like
you??
:-D |
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| Lee Olsen |
| Posted: Thu May 01, 2008 3:21 pm |
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On May 1, 4:47 pm, Marc Verhaegen <m_verhae...@skynet.be> wrote:
Quote: who is interested in the OPINION of a childish netloon like
you??
The childish netloon:
Yes, name calling is the only option you have left.
Quote:
You, you keep reading my posts, thanks.
Yes, my little boy,
Still liusting after little boys? Shame on you.
Quote: until the first sentence of your nonsense.
Says the wetloon who doesn't know a capybara from a mountain beaver.
What are the pros saying amout MV?
Message-ID: <1124421294.671438.286120@z14g2000cwz.googlegroups.com>
Jason Eshleman: "You, Marc, are a low-life, a real sleazebag
sociopath. If it makes you feel
better to repeat ad nauseum that no one has an argument against your
scenario, you really ought to get your medication adjusted. It might
actually make you less of a dickhead.
You are asking for someone to contradict something
that you've not made a case for. You are asking someone to prove a
negative. This isn't science, though I suspect you don't know what
science is and as such will continue your mentally ill diatribes."
http://www.aquaticape.org/whataat.html
Jim Moore:
"Marc Verhaegen now also often takes umbrage if you critique an AAT/H
claim that
he doesn't make himself. But then taking umbrage seems to be a
specialty with him;
his online method tends toward gratuitous insults, often as the sole
content of his
newsgroup posts, and continually reposting the same, non-responsive,
paragraphs
(earning him the nickname "macro-man" after the usual technique for
doing that),
and, starting from his very first online post in 1998, comparing his
position to Wegener,
Galileo, etc. These methods certainly don't help his argument,
instead placing his online
newsgroup contributions in the realm of the netloon." |
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| Marc Verhaegen |
| Posted: Thu May 01, 2008 6:47 pm |
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Quote: who is interested in the OPINION of a childish netloon like
you??
The childish netloon:
Quote: You, you keep reading my posts, thanks.
Yes, my little boy, until the first sentence of your nonsense. |
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