Re: savanna theory


richardparker01@xxxxxxxxx wrote:
rmacfarl wrote:
richardparker01@xxxxxxxxx wrote:
spiznet wrote:
...

Well, Spiznet, I've tried very hard to follow the logic of your
argument but got quite lost in the middle of it.

'For the most part, these human locales have been judged in the past
100 years to have been much more akin to closed & open woodland areas..'

- we seem to be taking an awful long time to realise that. Dart only
discovered Taung 80 years ago, and Leakey his stuff only 40 years ago -
why didn't they know that the 'Savannah' was long gone, replaced by
'closed & open woodland areas' ?:

And what, exactly, does that mean? Closed? Open? Woodland?

Why do you exclude open woodlands from the definition of a savannah?


'So if some anthro guy wants to use the actual documented spread of
savannah at 2mya for his theory of migrations, ok, thats a perfectly
valid theory, as far as it goes".

Is there any actual documented spread of savannah at 2mya? If so, I
would (very seriously) like to see it.

Seriously? Try reading a book about the Pleistocene. What do you think
the impact of the Ice Ages' onset was, if not a contraction of the
Equatorial rainforests and the spread of grassland? Why do you think
biodiversity is greater in the eastern & western margins of the African
rainforests than in the centre? Why do you think there are
geographically isolated populations of gorillas in the east & west? Why
does the fossil record show a worldwide increase in grass pollen over
trees, and a simultaneous increase in the number & variety of grazers
over browsers (e.g. Elizabeth Vrba's work on wildebeest diversity in
Africa).

Been there, done that. Seen the theories like 'East Side, West Side',
and so on and not been at all surprised when they've been upset and so
on... and on... and on.

Yes, there must have been "the Ice Ages' onset" sometime, but why
should that (only the first of well over a dozen alternating cycles)
have been the climate 'prime cause' for all that happened over the next
million year period? Or the one after that?

a) Why shouldn't it? &
b) What was "all that happened over the next million year period"?

Frankly, your hand-waving serves no purpose for pushing the flies away
at this distance, so if you'll need more than the above to interest me.

You asked for evidence of the spread of savannah 2 million years ago. I
provided it. Now will you pull your head in, or would you like to
explain why (with references) my evidence doesn't do exactly what you
said it wouldn't.


Where is the precise documented evidence of a spread of savannah at
2Mya? As the Pleistocene didn't happen for another 400,000 years or so,
I'm not much concerned with it in the context of this question.

The precise date for the start of the Pleistocene is 1.8 MYA:
http://en.wikipedia.org/wiki/Early_Pleistocene
"
The beginning of the stage is defined at 1.806 ± 0.005 Ma (million
years ago).
"

.... However the cooling had commenced well before this:
http://www.nature.com/nature/journal/v272/n5650/abs/272237a0.html
"
THE late Pliocene is characterised by a global climatic cooling1-4
and by widespread erosion of abyssal sediments by Antarctic Bottom
Water (AABW)5-6. The global cooling is dated between 2.5 and 3.0 Myr
based on the age of the oldest tillite in Iceland7, the initiation of
glaciation in the Sierra Nevada of the USA8, faunal changes in
Antarctic and sub-Antarctic deep-sea cores9-11, and a change in
carbonate preservation in the equatorial Pacific12. This cooling may be
synchronous with the development of the Northern Hemisphere ice ***
which has been dated by the first appearance of ice-rafted debris in
the North Atlantic at 3 Myr followed by a major influx at 2.6 Myr (ref.
13), and by a large change in the oxygen isotope record of benthic
foraminifera indicating an increase in ice volume at 2.6 Myr (refs 2,
3).
"


As for the rest of your rhetorical questions, I'd lump them together
with all the others that have been miraculously answered by 'Ah Yes!
Climate, of course!"

I take it you consider the following to be a rhetorical question also,
considering you have so far been deafeningly silent in response:

"[W]hat is it about AAH that, in your opinion, is so desperately
misunderstood by the scientific community?"


And since you've brought up the subject, yes, I would consider you one
of the 'regular ***-slingers' but since you're being relatively
docile, polite, well-mannered, and displaying some evidence of
conscious thought, I'll just hope you stay that way - my boy.

Hmm. Well I could just respond "*** you, Dickie-boy", because based on
past performance that's exactly the response you deserve. But instead,
I'll remind you & other players here that after your bleating about how
rude & unkind we all are, I offered to engage in a debate with you &
offered you the chance to post something meaningful about your own
ideas. And you responded - nada. Nincs. Niente. Sweet FA.

Your track record as a person of ideas & intelligence doesn't balance
well with your own well-developed reputation as a ***-slinger,
Richard. I, on the other hand, will stand on my record for balance, as
far as this forum goes.





"Hey, Marc, don't stop at hominid development, don't you *really* think
that, looking at it a certain way, that ALL evolution of ALL creatures
was caused by water (or water by-products) and that is pretty much the
solution to all life's evolutionary mysteries?"

Yes, of course, you're perfectly right on this point - "ALL evolution
of ALL creatures was caused by water (or water by-products)" but in
this forum we're only talking about the last 2.5 seconds of the 24 hour
clock analogy of the world's history, so perhaps we should think of
some other ideas.

See, a key part of the problem with AAH theorists is this determined
adherence to an umbrella hypothesis that says it was all due to water.
Once upon a time the theory was that humans evolved because brains
grew, hence the attraction of Piltdown & the dismissal of Taung,
because people wanted the brain to be important.

But evolution doesn't
work the way we want it to. It's not neat and orderly. It's chaotic,
and contingent on things, that happen in places at times.

Good thinking (or, at least, evidence of some thinking).

Patronising statements tend to fall flat if history suggests you're
dumber than the person you're trying to patronise.


The reasons for bipedal apes evolving from apes were not the same as
those for Homo evolving. Those events were separated by a greater span
of time than the gap between erectus & sapiens. Why would the same
explanation apply? In the Pleistocene, the world became colder, and
dryer. This climatic change influenced the evolution of hominids, just
as it influenced the evolution of wildebeests and whales...

The Pleistocene began, and Homo erectus apparently stayed just about
the same for another million years. Why?

a) Why not?

b) Your interpretation that it stayed the same is based on limited
evidence. Lifestyles, niches, morphology and dating are not well
understood for most of this period...

Ross Macfarlane

.

Quantcast