Re: Help me settle an argument...
- From: Vend <vend82@xxxxxxxxxxx>
- Date: Wed, 2 May 2007 13:33:33 -0400 (EDT)
On 1 Mag, 19:15, "Paul Crowley" <skjhkdjh...@xxxxxxxxxxxxxx> wrote:
"Vend" <ven...@xxxxxxxxxxx> wrote in message
news:f15ad0$2p0m$1@xxxxxxxxxxxxxxxxxxxxxx
I've stated it. There are NO chimp fossils
(although there are a few uncertain bits
that tell us little) so there is no evidence
there. Although Tim White called his
very early hominid 'a bipedal chimp'.
Actually there are two distinguishable species of modern chimps, and
the ancestor couldn't be possibly equal to both of them.
It is generally agreed (from DNA studies)
that bonobos split off from the main chimp
population around 1.5 million years ago.
They are an isolated population on the
southern side of the Congo River.
(Chimps cannot cross major rivers.)
They did not exist at the time of the
chimp/hominid split.
My point is that it's not possible for the human-chimp ancestor to be
undistinguishable from modern chimp since there are two
distinguishable species of modern chimp.
Do Sicilians have a knife fighting tradition?
Yes -- or they used to. Guns have
probably taken over now.
This appears to be made up. Evidence?
It is common knowledge.
Of ignorant people.
Heard of the feuds? Of the Mafia? Of
the weakness of Italian governments?
Italy as a political entity was formed in 1861. The Sicilian Mafia is
estimated to have originated approximately in the same period.
This is about 5 human generations, obviously a time too short for any
significant evolution.
Moreover, the violent activities of the Mafia involve only a minimal
part of the Sicilian population therefore couldn't have been a major
factor driving the evolution of the population.
The population (partly as a result of
all that) were extremely poor and guns
and ammunition were expensive.
The Mafia used mostly guns since its begining, and there isn't
evidence of extensive usage of knives for fighting in the general
population.
Anyhow, Sicilians aren't so short. The average stature in Southern
Italy is close to the average of various European countries:
http://en.wikipedia.org/wiki/Stature#Average_adult_height_around_the_world
Why do we need different explanations for facial and body hair
distribution in Asian people?
They are human features and we should
be able to use evolutionary arguments
to explain them -- and the differences
across human populations.
And why the explanation for the distribution of body hair should be
different for that of facial hair?
I would expect a correlation between body hair and facial hair.
African wild dogs (Lycaon pictus), for instance, hunt by chasing their
preys in the open African plains until they become exhausted:
"Like most members of the dog family, they are cursorial hunters,
meaning that they pursue their prey in a long, open chase, rather than
relying on stealth as most members of the cat family. Typically, about
85% of their hunts result in a kill."
http://en.wikipedia.org/wiki/African_Wild_Dog
Our ancestors probably did something similar.
How did they come to _evolve_ into
this (already occupied) niche?
Wild dogs and hyenas didn't kill every prey.
We can take it that (under your scenario)
they were present almost all the time
while hominids were evolving. They'd
have mopped up all the vulnerable
animals.
They aren't 100% efficient.
Canid and human niches are not totally overlapping,
Are you saying that canids (et al) were
absent from the hominid habitat?
Possibly in some areas. And even in the areas were they were both
present, they might not have been hunting exactly the same preys.
The niches overlap, but not exactly (If they did, one of the of the
two groups would likely be extinct by now).
and anyhow a new species can enter in an
occupied niche if it's able to compete with the previous occupants.
It is a highly specialised task, which
most predators do not begin to consider,
and it imposes great demands on the
anatomy of the few which do. No one
claims that early hominids (e.g.
australopiths) were able to do it. So
how would their descendants have
begun to evolve into it?
Early hominids (Orrorin tugenensis?) probably hunted small preys such
as monkeys in a forest or near-forest environment, not very
differently from what modern common chimps do.
As hominids begun to exploit more and more the new open grasslands,
they gradually adapted to cursory hunting that is more fit to open
areas.
Anyhow, your arguments seems to imply that since there are hyenas,
other animals such as wild dogs, jackals and lions can't exist in the
same environment, since they use a similar hunting strategy.
Consider what happens when rats and domestic cats are introduced in
ecosystems where they were not present.
This is a hopeless analogy. Hominids
were not introduced into Africa, after
having evolved on another continent.
Yet they entered in an environment where they were not present before
and managed to compete with the existing species.
What is different
about humans from other species that
allows weak muscles and fragile bones?
It can't be any kind of running, since no
other prey or predator species (specialising
in running) demonstrates those
characteristics.
I'm skeptical about your claim that humans have the weakest muscles
and bones among all animal species.
It is common knowledge -- among forensic
and anthropological scientists.
Your "common knowledge" was already shown not to be a reliable source.
When
bones are discovered, the first question
is: 'Are they human?'. The answer will
usually come quickly. Alan Walker and Pat
Shipman in their "Wisdom of the Bones"
discuss the issue. Human bones are remarkable
for the 'disaggregated' nature of their cells.
They can be broken easily.
I don't have access to that book. The only thing I found is:
http://jeb.biologists.org/cgi/reprint/98/1/289.pdf
If I interpeted it correctly (it is definitely not my area of
expertise), human bone strength isn't the lowest of all animals. It's
about the same of horses and rats.
Of course, basic facts like this are ignored
by the PA community
What community?
in the adherence to
theories about the heroic nature of our
ancestors: "Man, the Hunter". Such myths
go down so much better with students and
with the public generally. It also sounds
more impressive in funding applications.
Who would finance an investigation into
"Man, the Sloth"? Who would want
that on their resume -- especially if it did
not work out too well?
Paul.
AFAIK, humans have various features that are considered to be
adaptations to cursory hunting: long legs, lack of much long hair,
high surface density of sweat glands. I don't know how you can explain
those features in a sloth-like or another alternative hypothesis.
.
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