Anyone for paleoanthropology?
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28-08-2012, 01:50 PM
RE: Anyone for paleoanthropology?
(28-08-2012 12:02 PM)ghostexorcist Wrote:  There is a big difference between being classically trained and at the forefront of research and just having a keen interest in paleoanthropology. If you are the former, then you shouldn't have any problems providing said evidence.

'Evidence of expertise'? As in a court of law? And you are the judge? I think you're in the wrong place then, sir. This – afaik – is a debating forum, an opinion board. Afaic discussions here are based on common knowledge, common sense, and logic. Not on diplomas and grandiose academic titles. Mailordered or otherwise...

I put the above argument before you complete with my reasoning for it. You are explicitly invited to comment and critique that if you feel like it. But on the basis of the merits, or demerits, of that argument itself, not on the basis of whether I have blue eyes or not! Thank you.
Don't put the cart before the horse.

Quote:If you are the latter, you have to admit that there is always the possibility that you don't know nearly as much about the subject as you think you do.

What makes you assume I don't?
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28-08-2012, 01:53 PM
RE: Anyone for paleoanthropology?
(27-08-2012 09:52 PM)Apeman Wrote:  Hi everybody!
As an introduction I would like to give you some idea of some of the stuff that keeps me buzzing sometimes. But this is just one extreme, I warn you. Because for my next thread I plan on discussing the relative merits and benefits of extra-marital affairs, so stay tuned! Big Grin
Anyway, here goes:

OOA-BTA-OOA
Out Of Africa – Back To Africa – Out Of Africa

Currently, australopithecus sediba and homo erectus are mainstream favorites for being directly ancestral to us, homo sapiens. This suggests a line of descendancy from a. sediba via h. erectus somehow to h. sapiens.
I posit that is highly unlikely.

Their dating, locales, and physiology/morphology make it unlikely, imo:

A. sediba was dated to 1.997MYA in Sterkfontein, South Africa, had a cranial capacity of 420-450cm3, very long arms suggesting a lot of time spent in trees and knuckle walking when on the ground, and an average upright adult height of 1.3 meters.

H. erectus was dated to 1,8MYA and placed in Dmanisi, Georgia, had a cranial capacity of 600cm3, much shorter arms and longer legs, i.o.w. an upright long distance walker/runner, and an average adult height of 1.8 meters.

That would mean that in less than 200,000 years sediba moved 5,000 miles north (more like 50,000 miles on the ground probably; without bicycles!), while growing their cranial capacity and their length by 35 to 40%, and morphing into an entirely different species in an entirely different part of the world with an entirely different life style: homo erectus, the runner, the fire maker, the seafarer, the explorer.

That much of a difference in less than 200,000 years? Could be of course. Stranger things and faster evolutions have happened. But it's not very likely, is it?

What then could be more likely? Some kind of a multi-regional scenario of course. How about this one:

Imagine a scenario where one or both of the ardipithecines (4,4-5,6MYA; close to the Red Sea nexus) migrated from Africa to central Asia. Yes, 'OOA' gets earlier and earlier Big Grin. There in central Asia, separate from the left-behind homonoids (australopithecines and paranthropes) in Africa, the ardipithecines eventually independently evolved into an early h. erectus (around 2,5MYA?). This archaic h. erectus then went into a diaspora from central Asia in all possible directions. West to the Caucasus, the Levant, Anatolia, Iberia. South (back) to Africa. East to Malaysia, Java, Flores, Peking, and, who knows, the Americas...

Back in Africa h. erectus hybridized with (a.o.!) sediba in central/east Africa, creating the hybrid line that evolved into archaic homo sapiens around 200KYA. This archaic h. sapiens – a hybrid species to be sure! – left Africa (yes, this is that one; or actually two h. sapiens OOA waves) 100KYA and 70KYA. Only to meet, at first in the middle east, later everywhere, advanced evolutions of h. erectus that had been running around, and evolving/inter-hybridizing, for almost another 2 million years in Eurasia (and the Americas?). And the greatest of all inter-species 'hybridization' eras in homonoid history commenced, and never stopped since, 'hybridizing' everything into the mess we're now trying to unravel.

So we are all basically bastards, of course. Big Grin
But what else is new?

What does the DNA say?

Skepticism is not a position; it is an approach to claims.
Science is not a subject, but a method.
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28-08-2012, 07:50 PM (This post was last modified: 28-08-2012 08:17 PM by Apeman.)
RE: Anyone for paleoanthropology?
That's what needs to be studied now, imo.
Problem is we don't have much of those extinct hominids' DNA to study. Zilch, afaik.
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29-08-2012, 09:18 AM (This post was last modified: 29-08-2012 09:24 AM by ghostexorcist.)
RE: Anyone for paleoanthropology?
(28-08-2012 01:50 PM)Apeman Wrote:  'Evidence of expertise'? As in a court of law? And you are the judge? I think you're in the wrong place then, sir. This – afaik – is a debating forum, an opinion board. Afaic discussions here are based on common knowledge, common sense, and logic. Not on diplomas and grandiose academic titles. Mailordered or otherwise...

I put the above argument before you complete with my reasoning for it. You are explicitly invited to comment and critique that if you feel like it. But on the basis of the merits, or demerits, of that argument itself, not on the basis of whether I have blue eyes or not! Thank you.
Don't put the cart before the horse.

This is not a debate forum. This is a science sub-forum on an atheist website. Plus, you didn’t mention anything in your initial post about wanting to debate. I have no problem with people positing their own theories on science issues, but to dismiss the research of professionals, again, shows plenty of hubris. That would be like me, a former East Asian Studies major, arguing with a native scholar over the subtleties of the Chinese language. Sure, I have some experience with Chinese, but nowhere near that of a native speaker who has studied it for decades. Such people need to prove that their ability to dismiss professional research is based on years of experience and not armchair reading. Likewise, you can’t expect me to accept the theories of a faceless person on the internet without receiving some sort of background on their experience in paleoanthropology. I’m really not trying to be combative, just realistic. I apologize if I am coming off as belligerent. I’m just tired of seeing people come on here acting like they know more about science than the scientists do.

By the way, it has been suggested in the past that there has been hybridization in the human lineage before. The oldest fossils associated with the human lineage date to around 7 million years. However, genetic chronology points to the human-chimp speciation events happening around 5 million years ago. The geneticist Dr. David Reich thinks this suggests that the early human and chimp lineages continued to mate and finally split for a second and final time. Genetic chronology shows that the X chromosome in the human and chimp lineages split over a million years before the other chromosomes. Dr. Reich further suggests this could have been caused by hybrid females interbreeding with chimpanzees (since hybrid males would not have been able to reproduce). In addition, he further suggests that this interbreeding could have hastened human evolution since it would have allowed us to better adapt to the new environment of the African savannah. Paleoanthropologists like Dr. David Pilbeam are not quick to accept the information since genetic chronology only provides “relative ages” that need to be matched with dated fossil evidence. I don't think I've heard any more about this.

I think the biggest obstacle to your theory is the lack of DNA evidence. Future discoveries may cause A. sediba to lose its title as a new species. As I posted before, there are still some scientists that think it is simply a late branch of A. africanus.
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29-08-2012, 10:01 AM
RE: Anyone for paleoanthropology?
There was an article in Science Illustrated about Homo erectus that discussed the possibility of 2 separate out of Africa migrations. The idea is basically that the ancestor of Homo erectus migrated out of Africa into Asia, and then Homo erectus migrated back to Africa and Homo sapiens descended from erectus (or a similar species) and then migrated back out of Africa. It is a bit more complex and is currently not the most popular hypothesis. Further studies in Asia looking for early ape fossils will be needed and Paleoanthropologists are doing so.

The article also mentions the Aquatic hypothesis briefly too, but is also largely viewed with skepticism.

“Science is simply common sense at its best, that is, rigidly accurate in observation, and merciless to fallacy in logic.”
—Thomas Henry Huxley
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29-08-2012, 11:57 PM (This post was last modified: 30-08-2012 12:01 AM by Apeman.)
RE: Anyone for paleoanthropology?
(29-08-2012 10:01 AM)TheBeardedDude Wrote:  There was an article in Science Illustrated about Homo erectus that discussed the possibility of 2 separate out of Africa migrations. The idea is basically that the ancestor of Homo erectus migrated out of Africa into Asia, and then Homo erectus migrated back to Africa and Homo sapiens descended from erectus (or a similar species) and then migrated back out of Africa. It is a bit more complex and is currently not the most popular hypothesis. Further studies in Asia looking for early ape fossils will be needed and Paleoanthropologists are doing so.

The article also mentions the Aquatic hypothesis briefly too, but is also largely viewed with skepticism.

That's basically what I laid out in my O.P.
So apparently I'm not the only one with that train of thought, Mr. Exorcist.
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