Re: Bone density in mustelids




Op 06-12-2007 18:27, in artikel Xns99FE7376FFFB1mujinomega@xxxxxxxxxxxxx,
Mujin <umwinkl0@xxxxxxxxxxxxxxxxxxx> schreef:

....

FE Fish & BR Stein 1991 Zoomorphol.110:339-345
Functional correlates of differences in bone density among
terrestrial and aquatic genera in the family Mustelidae
(Mammalia) "the costs of maintaining an increased skeletal mass
increases according to locomotor function as follows : swimmers,
sedentary forms, slow runners, fast runners, and flyers"
No reason why erectus must be an exception, IOW, the H.erectus
endurance running hypothesis is pure nonsense.
....

You are missing the point, which is of course that pachyostosis is
not restricted to buoyancy adaptations, but occurs for other reasons
(such as stress) as well.

Don't be ridiculous: every biologist knows that a dense & thick
skeleton = slow-diving (just see the abstracts papers of Fish, Taylor
etc.I sent to s.a.p),

This is absolutely not the case. You are falling into the trap of a
logical fallacy here:
If A then B does not imply if B then A.
Yes, slow divers have a particular pattern of osteosclerosis.

Often, not always.
But you're not follwoing, I'm claiming the *reverse*:
All osteoscl.+pachyost.animals are slow divers.
No reason why fossil Homo fossils with these features must be an exception:
only creationists believe that humans are something special.

However, as I have shown from reference to the literature, osteosclerosis
is not unique to slow divers.
In the case of early Homo, the slight increase in the density and decrease
in medullary cavity in comparison to A'piths and Pan is *precisely* where
it would be expected if it was in response to the vertical stresses of
running and walking: spine, hips, femur, tibia. Tellingly, it is *not*
where it is found in slow, shallow diving mammals: the ribs, and in a
reduction of cranial sinuses.

You're rather selective in your reading:
1) We're not talking about "early Homo"(usu.syn.for habilis), but about
erectus: not "slight".
2) The places are totally unexpected in response to vert.running, eg, why
dense occiput?? why platymeria instead of latero-lateral flattening?? Etc.
3) Cursorial animals are lightly-built, just compare E.Afr.long-distance
runners to W.Afr.sprinters.
4) It's where it's found in sea-otters: esp.limbs & skull. I would not be
surprised it sea-otters turned out to have thick occipita.

You claim that early Homo dove for sessile foods on shallow water bottoms:
in this case we should expect a reduction in cranial sinus, an increase in
the density of the ribs (to counteract lung buoyancy) and an increase in
the density of the upper limbs (to facilitate the necessary head-down
foraging position).

Very speculative, but good thinking, but I'm claiming that erectus or their
immediate littoral ancestors were parttime slow divers *and* back-floaters
("parttime sea-otters").

1) Cranial sinuses generally He<Hs<Hn.
2) Ribs: AFAIK Hn>Hs.
3) Pelvis: pubis Hn<Hs.

In fact, we find the opposite is true: the sinuses increase,

In He?? No, no, see above.

the upper limbs reduce,

In He? Refs please?

the *lower* limbs increase in density.

AFAIK, He>Hn>Hs.
- Trinil: dense *distal* femora (kneeling??).
- Zhoukoudian > Trinil.
Heavy legs suggest regular wading?

Even worse, the ribs
remain much the same except in one critical feature: rather than the cone-
shaped thorax of Pan and A'pith (narrow on top, wide at the base, to
accomodate a large gut) Homo has an *inverted* cone, to accomodate larger
lung capacity. While it's true that a larger lung capacity *could* point
to early Homo needing to hold the breath while diving, you can't have this
increase in air volume without an equivalent increase in ballast - i.e.
increased density of the skull (via reduction of sinus) and ribs.

Ribs AFAIK: Hn>Hs. He??
Skull esp.occiput: He>Hn>Hs, but sinuses He<Hs<Hn.

Hs & Hy: barrel-shaped thorax.
Apiths & apes: inverted funnel-shaped.


but for some obscure reason, some medieval PAs
think they know it better of than the biologists & construct the most
far-fetched reasons to keep erectus on their savanna: head-banging,
honey eating, carnivore liver eating, tennis playing, kudu running,
thyroid & parathyroid disorders, etc.

Among other things, you appear caught up on a straw man derived from ideas
of early Homo's habitat that were tossed out just about as long ago as
Dart. Get with the times.

Just to illustrate that there are only ridiculous & far-fetched
"alternatives".


Nakedness plus thick SC fat is *only* seen in (semi)aquatic mammals
(don't confusewith the reverse).

The sea otter has little or no subcutaneous fat. Seeing as you are trying
to use the sea otter as your model,

No, no, very partly: diving cycles of 1.5-2 minutes, back-floating, stone
use, sessile animal seafoods (DHA etc.).
Some He (Java) have microwear indications of plant foods.
Our dexterity & hand anatomy shows resemblances to clawless otters.
I have no exact idea how our seaside ancestors lived, but currently I'm
thinking of a combination of waterside &/or aquatic plants, no doubt
molluscs (diving, but also beach??), occasionally drowned bovids or stranded
whales, of course seaside fruits esp.coconuts, birds' & turtle eggs etc.
Possibly they sometimes followed rivers inland. Etc.


how is it that early Homo became hairless and SC fat bearing?

Not so difficult:

Size: sea-otters (smallest marine mammals) spend 2 hours per day pruning
their extremely dense waterproof fur, but carying a SC fat-layer is probably
even more costly for these rel.small aq.mammals.

Besides, all gr.apes lack underfur. Early apes were no doubt aquarboreal:
vertical climbers-floaters-waders in swamp forests, see our TREE paper
(google "aquarboreal"). IOW, a fur was no option.

Conversely, the arctic fox also has subcutaneous fat deposits. Is the
arctic fox now semi-aquatic?

1) Snow is not dry AFAIK.
2) Again: try not to be too selective. Badgers have a lot of fat (SC &
internal) before winter. Woolly mammoths had fat in a hump & SC. Is the
arctic fox's SC fat seasonal? Rabbits have more fat than hares. Etc.

And what of the various seal species which have subcutaneous fat *and*
well developed pelts?

All non-tropical semi-aquatics outside the tropics.

You're too black-white thinking here. The reality is more diverse.

You are assuming a connection between hairlessness and subcutaneous fat
deposits that does not exist.

??
Too the contrary, my boy!
I suggest you to read my work before producing nonsense.
Why not read my first paper on AAT??

You are also assuming that human SC fat
deposits are similar in nature to those of aquatic mammals - they are not.

1) Again black-white generalising.
2) I'm not assuming that.

In fact, it is well known that humans do not develop fat deposits over the
whole body evenly, as occurs in marine mammals.

Evenly?? No mammal does that!

Instead, humans deposit
fat preferentially in specific regions of the body, just like other animals
that store fat as energy (and sometimes water) reserves, not as insulation.
Steatopygia is one such pattern which occurs in modern human populations
with a long history in African deserts.

Nobody can give 1 reason why our
ancestors could not have lived along coasts & rivers

Nobody needs to give reasons why our ancestors could *not* have lived along
coasts & rivers.

Not my problem that you don't want to give reasons why you think the earth
is flat: it's your problem.

*You* are the one with something to prove, and you have
two problems:
a) No one denies that Homo may have lived near water

Of course, but I'm claiming that our ancestors once dived parttime, etc.

b) There is a lot of evidence to show that early Homo relied on terrestrial
prey,

There is 0 evidence of "terr."prey: we have evidence of early butchering of
crocs, hippos, bovids, whales. It's obvious IMO that the bovids were drowned
when crossing/wding in rivers/swamps, possibly during the trek. You don't
believe, like some savanna fanatics here, that our ancestors 2 Ma ran after
kudus?? :-D

Gutierrez, M. et al. Exploitation d¹un grand cétacé au Paléolithique ancien:
le site de Dungo V à Baia Farta (Benguela, Angola). Comptes Rendus de
l'Académie des Sciences, Série 2, Sciences de la Terre et des Planètes 332,
357-362 (2001).
Bunn, H.T. Early Pleistocene hominid foraging strategies along the ancestral
Omo River at Koobi Fora, Kenya. Journal of Human Evolution 27, 247-266
(1994).
Fiore, I. et al. Taphonomic analysis of the late Early Pleistocene bone
remains from Buia (Dandiero Basin, Danakil Depression, Eritrea): evidence
for large mammal and reptile butchering. Rivista Italiana di Paleontologia e
Stratigrafia 110 supplement, 89-97 (2004).
Potts, R. & Shipman, P. Cutmarks made by stone tools on bones from Olduvai
Gorge, Tanzania. Nature 291, 577-580 (1981).
Stewart, K. Early hominid utilization of fish resources and implications for
seasonality and behaviour. Journal of Human Evolution 27, 229-245 (1994).
Kaufulu, Z.M. & Stern, N. The first stone artefacts to be found in situ
within the Plio-Pleistocene Chiwondo Beds in northern Malawi. Journal of
Human Evolution 16, 729-740 (1987).
Munro, S. Fauna of Selected Late Miocene to Early Pleistocene Fossil Sites
(BA Honours thesis, Australian National University, Canberra, 2004).


but precious little that shows early Homo relying on significant
quantities of marine prey.

See some of the refs above.
During most of the Pleistocene the coasts were c.100 m below the present
sea-level.

(in fact, all
Homo fossils are found there), but the few savanna-biased PAs left
still *know* (divine inspiration?)

No, physical evidence that you refuse to acknowledge or even comment on.

That *you* refuse to see or commment, you mean:
At Gona, Ethiopia, 2.5 Ma-old stone tools were deposited in ³floodplain
environments, close to margins of channels that carried the volcanic cobbles
used as raw materials for tool manufacture² (Semaw et al. 1997: 333).
Nearby, in the Hata Member of the Bouri Formation, hominid fossils of a
similar age to the Gona deposits were discovered in sediments containing
sandstone with bivalve and gastropod shells ³deposited by fluvial processes
associated with floodplains along distributary channels close to a shallow
fluctuating lake² (de Heinzelin et al. 1999: 625). This Member also reveals
evidence of cut and percussion marks on bones of medium and large-sized
bovids, though stone tools have so far not been discovered.
The Homo maxilla AL 666, dated to 2.3 Ma, along with a stone tool assemblage
(though no signs of butchering), was recovered from deposits of the Hadar
Formation, suggesting a landscape which was ³predominantly open, with
wetlands and bushed or wooded grasslands, and with stands of trees close to
the water source² (Kimbel et al. 1996: 559).
At Olduvai Gorge Plio-Pleistocene Homo remains are associated with deposits
containing ³cemented aggregates of the small benthic, freshwater clam
Corbicula² as well as crocodiles, hippos and fish (Blumenschine et al. 2003:
1220). Cut and percussion marks are found on a percentage (4.2 and 8.3%
respectively) of the long bones of larger mammals. Fish and gastropods,
judging by the remains of ?living sites¹, might have been consumed at
Olduvai Gorge, while the avian fauna included abundant waders (flamingoes,
herons, storks, rails, jacanas, plovers, sandpipers and stilts), swimmers
and divers (grebes, cormorants, pelicans and ducks) as well as marine birds
(gulls, terns and skimmers) (Leakey 1979).
The earliest occurrence of the genus Homo in the Turkana Basin is associated
with flood-plain deposits in which gastropods, fish, crocodiles, bovids,
equids, suids, cercopithecids and hippopotamids occur (Pratt et al. 2005).
During Plio-Pleistocene times the Turkana Basin contained a large lake
fringed by swampy wetlands as indicated by the numerous fossils of hippos,
crocodiles, fish (including a stingray, suggesting a marine connection at
the time), gastropods, bivalves, sponges and numerous ostracods. Lung fish,
water bucks, cane rats, monkeys, giraffes, buffaloes, camels, rhinoceroses
and elephants suggest a rich mosaic of wet, dry, open and closed habitats in
the vicinity of an extensive lake, or large river (Feibel et al. 1991).
The most complete skeleton of an early Homo specimen, KNM-WT 15000, the
so-called ?Turkana Boy¹ of Nariokotome, Kenya, was discovered on the western
side of the Turkana Basin. It lay among reeds and hippopotamid footprints,
and the most abundant faunal remains associated with it were water snails,
fish and turtles (see Table 6).
The Plio-Pleistocene Shungara Formation in the Omo Basin contains an
archaeological assemblage as well as molluscs (including freshwater oyster
Etheria reefs), fish, crocodiles, hippopotamids, bovids, cercopithecids,
turtles, suids and other vertebrates. The archaeological occurrences ³are
all in proximal river settings² (Clark Howell et al. 1987: 696).
In the Western Rift Valley, the Senga 5A site (2­2.3 Ma) contains artefacts
associated with gastropods, bivalves, fish, hippopotamids, suids and bovids
in a ³low-energy littoral lacustrine setting² (Harris et al. 1987: 724).
The Plio-Pleistocene Chiwondo Beds of Malawi have yielded Homo fossils as
well as fragmented remains of fish, turtles, crocodiles and large mammals.
They also contain molluscs ³in consolidated beds of carbonate cemented
sandstone. Molluscan shell beds crop out as benches up to several meters
thick and several hundred meters wide² (Schrenk et al. 1995: 59).
The late Pliocene Chemeron hominid (KNM-BC 1) was deposited in a lake filled
basin where fish remains were abundant: ³Molluscs also lived in the lake,
and locally their remains accumulated to form shelly limestones. ? There is
little doubt that the fossil came from the Upper Fish Beds² (Martyn and
Tobias 1967).
The Dmanisi Homo fossil site, dated to 1.8 Ma, is located at the confluence
of two rivers, where at the time a lake or pond had formed due to the
blocking of a river by a lava stream. ³The hominid site itself was likely
located near a lake or pond, rich in lacustrine resources. This biome,
together with the adjacent forest-steppe formations, created a highly
productive ecotone rich in animal and plant resources² (David Lordkipanidze,
personal communication to MV). The inhabitants might have eaten hackberrys,
since abundant seeds have been found at this site (Gabunia et al. 2000).
Early Pleistocene archaeological sites from the Jordan Valley include
Erk-el-Ahmar and ¹Ubeidiya. These sites are associated with lacustrine and
fluvial deposits rich in fresh water gastropod and bivalve remains as well
as fish, turtles, hippos and birds (Bar-Yosef and Tchernov 1972).
Aïn Hanech, an archaeological site in Algeria dated to about 1.8 Ma, was
formed on an alluvial floodplain cut by a meandering river (an oxbow lake),
and may indicate repeated activities by hominids at a shallow river
embankment (Sahnouni et al. 2002).
At Pabbi Hills, Pakistan, artefacts of Pliocene age, about 2 Ma, have been
discovered in deposits which also contain crocodiles, turtles, aquatic
gastropods and bivalves. The molluscs suggest a large, slow-moving river
with clean, shallow water less than five meters deep, analogous to
unpolluted sections of the Ganges River (Dennell 2004).
The site of Mojokerto (Perning), on the Island of Java has been dated to
between 1.5 and 1.8 Ma. This coastal deltaic environment (Huffman 2006)
contained fresh water and marine molluscs, which would have been easily
procured and consumed by early hominid inhabitants (Frank Wesselingh,
personal communication to SM).
At Sangiran, also on Java, where H. erectus was found, ³a thin layer of
diatoms (uni-cellular marine phytoplankton) and dark clays with a marine
musselfauna was deposited by the sea, as was noticed and described before by
Professor Martin from Leiden² (von Koenigs-wald 1981).
Hominids on Java were using mollusc shells to butcher mammals, presumably to
gain access to nutritious meats, as early as 1.5 Ma (Choi and Driwantoro
2007).
The archaeological site of Majuangou (Nihewan), in China, recently dated to
1.66 Ma, reveals that hominids inhabited a lake filled basin, where the
remains of aquatic molluscs, and the leaves and fruits of aquatic plants
have been discovered, indicating a low energy lake-shore or marsh
environment (Zhu et al. 2004).
In the Middle Awash of Ethiopia, the Daka Member of the Bouri Formation,
dated to 1 Ma, contains artefacts, Homo erectus cranial and post cranial
bones, abundant hippo fossils, as well as gastropods and bivalves associated
with alluvial, lakeside beaches or shallow water deposits in distributary
channels (Asfaw et al. 2002).
Buia, in Ethiopia, contains Homo erectus fossils and artefacts dated to 1
Ma. These occur in deltaic deposits of the Alat Formation, which also
contains fish and freshwater gastropod (Melanoides) remains (Abbate et al.
2004). Evidence that hominids butchered medium to large-sized bovids,
hippos, and a crocodile, also come from these deposits (Fiore et al. 2004).
A partial Homo cranium from the same stratigraphic level as Acheulian
artefacts from Olorgesailie, Kenya, has been dated to between 0.97 and 0.9
Ma. The sandy silt adhered to the frontal bone of this specimen contained
amphibian bones and the tooth of the swamp rat Otomys sp., which today
inhabits thick grasses in and around the swamps, lakes and rivers of East
Africa (Potts et al. 2004).
The Angolan site of Dungo V reveals evidence for the exploitation of a large
whale (Balaenoptera sp.) on a former beach more than 0.35 Ma. Closely
associated with the whale skeleton were numerous Lower Palaeolithic
artefacts, together with numerous molluscs, other marine invertebrates and
shark teeth (Gutierrez et al. 2001).
The earliest evidence for human activity in northern Europe comes from the
site of Pakefield, England, about 0.7 Ma, where artefacts from estuarine
silts containing marine fauna have been discovered. The majority of
artefacts derive from ?Unio bed¹ coastal river deposits (Parfitt et al.
2005).


Mujin, I don't want to waste your & my time with repeating obsolete
discussions. I know your "arguments" (below, snipped), but I'm not
going to read them again.

If you didn't read my arguments, how do you know you already know them?

I know all the usual counter-arguments. I haven't seen anything new in what
you wrote above. It's a bit better than the usual savanna nonsense, that's
why I took the time to answer you. I will provide a translation of your
claim: "I actually have no response to the evidence that features I claim to
be unique to savanna mammals are actually present in other mammals as well
for a variety of reasons not related to a savanna lifestyle, so I would
prefer to snip the evidence and pretend that I have already answered them."
It's clear that you have nothing but rants, out of context quotations, false
generalizations, and wilful blindness in favour of your argument. Let us
know when you have some actual scientific evidence, will you?

.

Relevant Pages

  • Re: Follow the Evidence
    ... The Homo maxilla AL 666, dated to 2.3 Ma, along with a stone tool assemblage ... At Olduvai Gorge Plio-Pleistocene Homo remains are associated with deposits ... Fish and gastropods, ... and divers as well as marine birds ...
    (sci.anthropology.paleo)
  • Re: Hs living in caves three miles from the sea (Re:Hslittoral164 ka
    ... is no evidence for early Homo ... was recovered from deposits of the Hadar ... Fish and gastropods, ... and divers as well as marine birds ...
    (sci.anthropology.paleo)
  • Re: Tobias strikes out: Bushmen rarely drink water
    ... The Homo maxilla AL 666, dated to 2.3 Ma, along with a stone tool assemblage ... was recovered from deposits of the Hadar ... Fish and gastropods, ... and divers as well as marine birds ...
    (sci.anthropology.paleo)
  • Re: Tobias 1995
    ... The Homo maxilla AL 666, dated to 2.3 Ma, along with a stone tool assemblage ... At Olduvai Gorge Plio-Pleistocene Homo remains are associated with deposits ... Fish and gastropods, ... and divers as well as marine birds ...
    (sci.anthropology.paleo)
  • Re: Wet ape nonsense was (Re: Savanna nonsense)
    ... The Homo maxilla AL 666, dated to 2.3 Ma, along with a stone tool assemblage ... was recovered from deposits of the Hadar ... Fish and gastropods, ... and divers as well as marine birds ...
    (sci.anthropology.paleo)