Re: kuduburgers to go

Op 03-11-2007 17:11, in artikel
1194106313.671780.153630@xxxxxxxxxxxxxxxxxxxxxxxxxxxx, Lee Olsen
<paleocity@xxxxxxxxxxx> schreef:

Loren Cordain, Bruce A. Watkins, Neil J. Mann
Fatty Acid Composition and Energy Density
of Foods Available to African Hominids
Evolutionary Implications for Human Brain Development
World Rev Nutr Diet. 2001, vol 90, pp 144-161
"With the emergence of species of our own genus (Homo habilis) at
least 2.3
million years ago [1], a rapid increase in hominid brain mass
relative
to body
mass (encephalization) occurred [2, 3]. Figure 1 shows that the range
of cranial
capacities for Homo habilis significantly exceeded that of earlier
Australopithecus
species, whose brain volumes remained constant for at least 2 million
years.
Slightly prior to the emergence of Homo habilis in the fossil record
was the
appearance of primitive stone tools [4] whose function was to butcher
and disarticulate
either scavenged or hunted carcasses of African prey animals [5, 6]...

My little boy, try to follow a bit, it's not so difficult:

1) tool use:
Chimps & orangs (& gorillas rarely) use tools (P & Po split c.15 Ma).
Chimps hunt alone (Pp) or in groups (Pt), but don't need tools to butcher &
eat colobus monkeys etc. Carnivores don't use tools (they have teeth & large
mouths, you know), but Homo populations used shells & stones to butcher
bovids at least 1.5 Ma (Driwantoro). Mangrove capuchins use stones & shells
to remove & open oysters. Chimps crack nuts with stones. Sea otters open
shellfish with stones. Bones, stones & shells are much more abundant at the
waterside than in the open savanna.

2) brain-specific fatty acids (DHA etc.):
Docosa-Hexaenoic Acid etc.are abundant at the waterside, where all early
Homo fossils are found next to shells etc.(Gona, Mojokerto etc.etc.), but
no, Cordain cs.are so convinced of their Holy Savanna Truth that they want
to steal bones from lions & hyenas & crack open bone marrow of savanna
bovids to get minute amounts of DHA!

Why don't the savanna fanatics listen a bit to what biochemists have to say
on this instead of wildly fantacising, eg,
- C.Broadhurst cs.1998 Brit.J.Nutr.79:3-21
"Rift Valley lake fish and shellfish provided brain-specific nutrition for
early Homo"
- C.Broadhurst cs.2002 Comp.Biochem.Physiol.B131:653-673
"Brain-specific lipids from marine, lacustrine, or terrestrial food
resources: potential impact on early African Homo sapiens"
- M.Crawford cs.1999 Lipids 34:S39-S47
"Evidence for the unique function of DHA during the evolution of the modern
hominid brain"
- M.Crawford cs.1972 in K.Elliot & J.Knight eds "Lipids, malnutrition and
the developing brain":267-292 Elsevier Amsterdam
"Nutritional influences in the evolution of the mammalian brain"
- S.Cunnane 2005 World Scient.Publ.Comp. Singapore
"Survival of the Fattest: The Key to Human Brain Evolution"
- S.Cunnane cs.2007 Am.J.hum.Biol.19:578-581
"Docosahexaenoic acid and shore-based diets in hominin encephalization: a
rebuttal"

Got it, my boy?

Brain-specific FAs = waterside.
Okidoki?
At the Rift lakes or at the seaside, but not in open savanna!

The original ?open plain¹ ideas were obviously hypothetical, but soon the
general impression of human ancestors coming out of the trees and colonizing
the vast plains became set in the minds of most anthropologists, and
different ideas ­ some more improbable than others ­ were put forward to
explain how savannah-dwelling ancestors might have found enough food and
water to survive on the open plains ­ as if the hypothesis had already been
proven. Human characteristics were discussed in an evolutionary setting
that involved a movement from the forests to the open plains, and reasons
for these characteristics always tended to revolve around the ?open plain¹
theme (see Table 2). Even the most far-fetched of these ideas (for example,
honey collection, liver consumption, or food collection at noon on open
plains) have been seriously considered and published in scientific journals.
Such ad hoc explanations are comparable to the hypothetical ?land bridges¹
between Africa and South-America that were popular in geology before the
theory of Plate Tectonics became accepted.
What is striking about these hypotheses is their combined diversity. Some
rely on hunting large game, others on small game, some on scavenging bone
marrow, or brains, or livers, or collecting seeds, or tubers, or honey.
Some of these ?open plain¹ models are more typical of slow-moving animals
(feeding on belowground resources), others of fast-moving mammals (³bouts of
strenuous activity²), and others rely on endurance (following migrating
ungulates, or the dogged pursuit of prey). This diversity of theoretical
models suggests that the ?open plain¹ scenarios are not the result of usual
biological thinking. In evolutionary biology, hypotheses are not just
?possible scenarios¹, but normally the result of solid analyses of
relationships between form and function. Biologists usually do not propose
a scenario to explain the evolution of an animal without a careful
comparison of different features of this animal with similar features
(convergences) of other, not closely related species.
Whereas modern biology sees evolution as a sequence of overlapping niches
(Kemp 2007), the proposed ?open plain¹ lifestyles of these early human
ancestors are discontinuous and have little or no overlap. Frequently they
are incompatible with each other. Moreover, they suppose that humans
collected foods without the typical adaptations that other mammals use when
they collect the same foods. We have no large digging-claws, for example,
we are slow runners (only some 36 km/hr over short, and some 20 km/hr over
long distances), and we are very prone to dehydration by depletion of water
and salts. We are heavily-built creatures with extensive fat tissues and
(in archaic Homo) heavy bones, features that are not seen in cursorial
species. Our cheekteeth lack the seed-grinding adaptations of baboons, while
the human gastro-intestinal tract and digestive anatomy and physiology
resemble frugi-omnivores such as suids, not carnivorous mammals (Stevens
1990). This contradiction has been labelled the ?baboon paradox¹, because
we would expect humans to be more similar to baboons if we evolved on the
savannah as they apparently did (Bender 1999).
The collection of waterside food resources, on the other hand, is compatible
with the presumed lifestyle of early apes, and fits with modern human
food-gathering strategies. Shifting from a fruit-based diet to a diet
including more waterside foods such as coconuts and shellfish does not
require significant behavioural modification. The use of tools to open
hard-shelled nuts and fruits is easily transferable so that the meat of
certain molluscs can also be procured (capuchin monkeys use tools to open
fruit, nuts and shellfish), and shellfish, like fruits and nuts, are sessile
food resources that need only be found and gathered, not chased or hunted.
From such fruit, shellfish, plant and egg-gathering it is not difficult to
envisage the incorporation of waterside catching of insects, frogs, fish or
birds, and the butchering of turtles, crabs, whale or bovid carcasses found
at the water¹s edge. We do not claim to know exactly how this waterside
lifestyle evolved, but we are confident that the limited diving skills of
humans came about as a result of increased time spent foraging under water.
As to how frequently our ancestors may have dived or waded or collected
fruit from trees or foods along the shore at low tide, or how long our
ancestors¹ waterside phase or phases may have lasted, these are all
questions requiring further investigation.

Table 2. Diverse savannah hypotheses of human origins.

Raymond Dart 1960 Osteodonto-keratic Culture ­ Savannah hunting
Robert Ardrey 1961 Man the Mighty Hunter ­ African Genesis ­ Adult men
hunting large game
Mikhail Nesturkh 1967 Herd instinct developed along with bipedalism as
our ancestors moved to more open territory.
Desmond Morris 1967 Mighty Hunter ­ The Naked Ape ­ Fur loss for easier
sweating
Clifford Jolly 1970 The Seed Eaters ­ Savannah baboon model
John Napier 1971 Open grassy spaces provided ?arenas¹ where new
locomotor skills could be safely practiced.
Hatley & Kappelman 1980 Belowground food resources
Walker, Zimmerman & Leakey 1982 High dietary intake of carnivore livers
­ Scavenger model
Hanna & Brown 1983 Bouts of strenous activity for hunting or digging
outside the forest
Peter Wheeler 1984 Savannah foraging at noon, to minimise solar radiation
David Carrier 1984 Dogged pursuit of swifter animals over 1 or 2 days
Sinclair, Leakey & Norton-Griffiths 1986 Bipedal trekking after herds of
migrating ungulates
Mark Skinner 1991 Savannah bee brood consumption ­ Tall grass savannah &
tropical forest
Richard Wrangham cs.1999 Cooking and bringing food to a processing area
Bramble & Lieberman 2004 Endurance Running over vaste plains
Dennell & Roebroeks 2005 Ability to ingest large amounts of meat ­
?Savannahstan¹
Richard Wrangham 2005 Delta hypothesis ­ Okavango-like savannah ­
Omnivory


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