Re: Clark's dilemma

rmacfarl wrote:

The notion that the evolution of a species could be
driven by the state of its neonates' legs (determined
in turn by the nature of its brain) must be one of the
silliest of all time.

Not contradicted.

Human infants are essentially helpless at birth. They are not strong
enough to hold their heads up unaided, let alone grip onto their
mothers. This is in direct contrast to the precocious newborns of
great apes and most other primates. However, unlike other animals who
produce altricial young, such as many rodents or small birds, this is
not because humans' reproductive strategy is to produce a lot of
offspring and expect very high attrition.

Wrong. There are different reproductive strategies
("r": producing many with minimal care, relying on
the remote chance of success -- versus "K" where
much care is lavished on a small number). You are
mistakenly associating "r" with altriciality and
"K" with precocity. But many species use an "r"
strategy with precocity -- e.g. crocodiles. Many
use a "K" one with altriciality, e.g. bears, seals,
kangaroos, other marsupials.

The reason why human infants are so undeveloped at birth is directly
attributable to brain size and brain growth.

Sheer nonsense.

Great apes' and other
primates' brains roughly double in size from birth until adulthood.
Human infants' brains, on the other hand, double in size in the 12
months following birth, during which time their bodies also roughly
double in size (comparable to a foetal rate of brain growth). After
their first year, human brains double in size again during the rest of
their childhood and adolescence - i.e. until their late teens, while
their bodies grow 10-fold. So why do human babies' brains grow at
foetal rates for a year after birth? ...

.... A question only a man would ask... The answer, of course, is that
there is a physical limitation for the women, whose pelvises, already
highly modified for bipedalism, then have to be even wider relative to
males to deliver their already abnormally large-brained babies. If
they tried to deliver young of the size and brain development of a 1-
year old human, they would barely be able to walk.

Utter nonsense.

I am not disputing FACTS -- but the REASONS
for those facts. Human infants are altricial
because it would be highly dangerous for them
to be precocial, and to be able to wander around.
Relative precocity is not a problem for chimp
infants, because they stay attached to their
mother (and they also need a certain amount of
strength to be able to hold on). Since hominid
infants -- as part of the requirements of the niche
-- are lying there doing nothing, they are able to
develop differently from chimps, and grow their
brains, etc. at different rates.

The requirements of the NICHE come first.
You cannot begin to describe why an animal
develops in one way or the other without
FIRST setting out the niche.

Steven Stanley's hypothesis is that the change from australopiths with
ape-sized brains to early Homo is linked to a change in niche. He
accepts the evidence that australopiths were likely to have been semi-
arboreal, and would (in my phrase) "belt up the nearest acacia" when
threatened by predators.

Here are pictures of typical acacias.
No hominid would have belted up them:

http://www.pbase.com/kiwilassee/image/28241501
http://lh6.ggpht.com/__p_aVFyab8Y/R7yyDu-T6jI/AAAAAAAAAyc/lZ0za9xBxPY/thorns.jpg

This strategy works as long as the young can
grab on to Mum & hold on for the ride, but an altricial human newborn
could not do this. Stanley then specifically links the shift in niche
to a large-bodied, large-brained terrestrial human to infants' brain
growth

Except that, of course, he doesn't. He does not
describe the stages. There can be no remotely
sensible account of how this supposed process
took place.

- essentially, in order to have a big Homo brain, you have to
stay on the ground, so you have to be big enough and ugly enough to
survive threats from dinofelids etc. while you're there.

As an entirely separate point, THAT makes no
sense at all. Hominids were -- by comparison
with contemporary predators -- tiny, weak and
pathetic. They were lunch-size bites.

Another thing that Stanley does is to link the niche shift to the
change in geological eras - the colder dryer Pleistocene (aka "the Ice
Ages") after the warmer, wetter Pliocene.

Except that he doesn't. It can't be done.
Tell us how many new species came into
existence around 10 kya, when there was
drastic climate change. Or around the
(drastic) end of the last inter-glacial
at about 110 kya. It just doesn't happen.
It can't happen.

Not exactly a radical concept - except, so it seems to you.

Stupid sheep say 'baa' because other stupid
sheep say 'baa'. It's not a good logical
argument.

No ***. Like apes keeping pet dogs to protect the kiddies, perhaps?

You're an ape. Ever had a dog?

Why do you think the geologists define the Pliocene and Pleistocene as
different ages?

Look it up. These were defined by Charles Lyell
from work he did in 1828/9 in Southern France and
Italy. If such work could be done afresh, wholly
different classifications would be used. They
apply locally (if uncertainly), but other systems
have had to be brought in for other parts of the
world.

Your ignorance is only exceeded by your arrogance. The impacts of the
Pleistocene - the Ice Ages - are known from worldwide and from multi-
disciplinary evidence - geology, biology, physics, chemistry, ... You
just show yourself up for a fool when you make statements like that.

The Pleistocene is not much of a problem.
Ice ages produce glaciers, the evidence for
which is easy to see. But the onset of the
Pliocene (and if such a period should be so
defined at all) is much more uncertain.
See:
http://en.wikipedia.org/wiki/Pliocene

" . . For most of North America, a different system (NALMA) is often
used that overlaps epoch boundaries:
* Blancan (4.75–1.806 mya)
* Hemphillian (9–4.75 mya); includes most of the Late Miocene
Other classification systems are used for California, Australia,
Japan and New Zealand. . . "

Try this: http://tinyurl.com/VrbaTOP

Vrba is a total idiot. Apparently the only
animals on earth were humans.


Paul.


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