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| Ardi, and the impact on evolution...
Posted: 10/20/2009 7:52:46 PM | So...I came across this link:
http://www.ethioplanet.com/news/2009/10/03/oldest-human-skeleton-found-in-ethiopia-older-than-lucy/
This may change, a lot about our current ideas of evolution. There may be more to the story...
I found these two questions, very provocative...
Did primitive Ardipithecus undergo some accelerated change in the 200,000 years between it and Australopithecus—and emerge as the ancestor of all later hominids? Or was Ardipithecus a relict species, carrying its quaint mosaic of primitive and advanced traits with it into extinction?
Any thoughts? | |
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| Ardi, and the impact on evolution...
Posted: 10/20/2009 8:10:36 PM | If cat's and bunnies started breeding on a regular basis, stepping forth would be an entirely new creature with traits of them both. (I read somewhere this was possible) Would this be a step forward in evolution... or just really weird? lol... I think I made my point...
God did not make man as we see them today, for that matter, I'm pretty sure Moses wrote about God in his own personal... delusional... and possibly greed motivated image.
Look at how many diverse cultures we have today, and every one of them clearly show significantly different features in individuals from one another. Given enough time, as the world comes more together, we will start having the best traits of one another and move forward as something different, and possibly better than before. | |
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| Ardi, and the impact on evolution...
Posted: 10/20/2009 8:15:15 PM |
Given enough time, as the world comes more together, we will start having the best traits of one another and move forward as something different, and possibly better than before.
You described evolution | |
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| Ardi, and the impact on evolution...
Posted: 10/20/2009 9:15:11 PM | This is not a post about the validity of evolution...
This is a post about recent findings, and the impact on evolution as far as we know it.
This discovery, suggests that the divergence happened way before than what we had originally thought...
That is what I am interested in...
Especially with:
Did primitive Ardipithecus undergo some accelerated change in the 200,000 years between it and Australopithecus—and emerge as the ancestor of all later hominids? Or was Ardipithecus a relict species, carrying its quaint mosaic of primitive and advanced traits with it into extinction?
These questions... | |
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| Ardi, and the impact on evolution...
Posted: 10/20/2009 9:43:07 PM | It's hard, at this point, to say how Ardi is going to impact on the overall picture of the evolution of human beings. As I understand it, she has characteristics of early humans, but also of lemurs which are more of a "cousin" than a direct descendant.
They may well represent a true "branch point" for human evolution. However, the problem with having this one sample, it's difficult to make definitive conclusions. But it is certainly evocative, as well as provocative. | |
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| Ardi, and the impact on evolution...
Posted: 10/20/2009 11:11:45 PM |
If cat's and bunnies started breeding on a regular basis, stepping forth would be an entirely new creature with traits of them both. (I read somewhere this was possible) Would this be a step forward in evolution... or just really weird? lol... I think I made my point...
Cats and rabbits cannot breed to produce an offspring. I don't know where this urban myth originated but it has taken on a life of its own to the point a lot of people, if not most, have heard it so often it has begun to sound real. | |
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| Ardi, and the impact on evolution...
Posted: 10/21/2009 12:15:33 AM | >>>I'm pretty sure Moses wrote about God in his own personal... delusional... and possibly greed motivated image.
Its my understanding that the bible isn't Mose's account of the story- he didn't write it. | |
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| Ardi, and the impact on evolution...
Posted: 10/21/2009 1:25:23 AM |
As I understand it, she has characteristics of early humans, but also of lemurs which are more of a "cousin" than a direct descendant
Any resemblance to lemurs is coincidental - a case of plesiomorphy, atavism, or convergence.
The surprising and significant aspects are not its taxonomic position, but unexpected aspects of its biology.
Thus far, it's fairly clear that the genus itself IS a hominine and apparently part of our direct ancestry. Whether A.ramidus, A.kaddaba, or some other species is a direct ancestor is more debatable. Regardless, it is very close to the origins of Australopithecus.
The discovery of Ardipithecus was NOT a surprise. It was planned. Genetically, we expect that our last common ancestor with chimpanzees was 7-8 million years ago. In fact, with our currently highly accelerated rate of evolution, we could have diverged millions of years more recently, so that age is not a problem to accomodate. The trouble is, our oldest clear ancestor has been Australopithecus afarensis, at around 4 million years. That leaves a 3-4 million year gap in our knowledge, which is nearly half of the ancestry we wish to examine. Since that time, the fossil record has been abundant. So how do we fill that gap? By looking for sediments which are 4-8 million years old, rather than those which are less than 4 million years! So...that's what they did. Look, and ye shall find.
So what were the predictions, the traits expected or hoped for?
First of all, chimpanzees are knuckle-walking forest-dwellers with opposable great toes. All other known fossil hominines [Homo, Australopithecus, Zinjanthropus, Sahelanthropus, Paranthropus, etc] have been bipedal savanna-dwellers with non-opposable toes.
What was being sought then, was an older ancestor with less of OUR traits and more chimpanzee traits. It was expected that this would include a savanna knuckle-walker, the hypothesis being that our ancestors moved out of a forest environment where climbing was more important and knuckle-walking was convenient on the ground. From the forest, they entered the growing grasslands as knuckle-walkers. On the open ground, an upright posture was advantageous, giving a better view of the surroundings. The opposable toe was less useful than a pure walking foot, and likely a hindrance which would quickly disappear. Once upright, carrying a growing brain would be easier for later generations.
What was found, was that A.ramidus was bipedal, and NOT a knuckle-walker. It also still possessed opposable toes and was an apparent tree-climber. Thus, it comes as no surprise that they lived not in grasslands, but in forests.
This kills some old hypotheses and leaves questions as to what alternative explanations might be viable. Clearly, moving to grasslands was not the reason for bipedality [though bipedality was probably a great advantage there, and thus contributed to subsequent success and diversity], so what was?
We still have a huge gap in chimp ancestry. So far, we assume that their ancestors were all knuckle-walking forest dwellers. That's reasonable, since our shared distant relatives, the gorillas, also fit that description. We're the odd ones out.
At this point, the only appreciable difference between our ancestors [Ardi] and chimps is that one is bipedal and the other is a knuckle-walker. They would seem to otherwise occupy the same environment and habitat. The gap is clearly closing, but filling that remaining 3 million years is now more important and problematic, since we now lack a clear reason for the divergence. Identifying the reason will thus be more difficult, even with suitable fossils. | |
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| Ardi, and the impact on evolution...
Posted: 10/21/2009 9:11:00 AM | Re: hhheavenly1
Cats and rabbits cannot breed to produce an offspring. I don't know where this urban myth originated but it has taken on a life of its own to the point a lot of people, if not most, have heard it so often it has begun to sound real.
I think it started with a TV appearance of some Manx kittens. Because they kinda look like a cross between cats and bunnies (and there so not) it might be easy to see why some people may jump to that conclusion. I was just saying that as someone made a point early about humans coming from two pre-existing species that may have interbred their way into extinction.
Re: Jiperly
Its my understanding that the bible isn't Mose's account of the story- he didn't write it.
If you where to google search "who wrote the first 7 books of the bible?" the answer comes back simply "Moses!" Of course the original Hebrew texts of the "Torah" (look it up) consists of about 20+ something books and authorship is generally attributed to Moses the Teacher.
So it my opinion... that the first 7 books of the bible... that was the very foundation of everything religious that followed, was written... by a man that wheeled the name God as his personal broadsword for power.
It depends on your perspective really, you can believe Moses was doing the work of God... or you can see a man who talks to illusionary burning plants and animals, suffers from illusions of grandeur, and slaughters innocent people for breaking rules he felt everyone should follow... instructed to him by God of course... (Picking up sticks on the Sabeth day was apparently punishable by death... because even God rested on the 7th day of creating everything as we know it) (Yah, no corruption of power there)
Now, I'm not a religious person... as you can probably tell... But I don't think it's hard to understand why Jesus walks around basically trying to undo all the crap Moses laid out about God. But even he had to work through the system to work for the system, as it was so ingrained into peoples lives that not making reference to it would be completely impossible. But it's also this kinda conversation that led to wars and the brutal, slaughter, and sometimes tortures deaths of countless lives.
... SAD!
You can talk about alternative ideas about what God means to you on an open forum like this one... but good luck if you attempted that kinda blasphemy in a church... You would be nailed up on a cross and possibly burned alive. (Exaggeration) | |
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| Ardi, and the impact on evolution...
Posted: 10/21/2009 9:20:37 AM | It seems that it's pretty much impossible to have a straight on scientific discussion in this forum without the religion debate getting tossed into the mix.
Why is that ?
The OP simply wants to discuss, specifically, the fossil Ardi and its implications on how far back humans branched in the evolutionary scale.
How did religion fall into this ? | |
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| Ardi, and the impact on evolution...
Posted: 10/21/2009 11:06:44 AM | i have followed some of the articles on ardi for a while now, and it is exciting to see the analysis of the skeleton is now providing some insights. and, as the OP has suggested "this may change a lot about our current ideas of evolution" .. based on what analysis has taken place i think there is no doubt to that. and i will certainly defer to those whom are more skilled than i to offer a comment on that. but this statement seems to sum it up .. "What Ardi tells us is there was this vast intermediate stage in our evolution that nobody knew about, it changes everything" - Owen Lovejoy, anatomist at Kent State who analyzed ardi's bones.
but what this reconfirms and proves to me is a couple things. science is never a totally linear process, what we think we know today may have to be revisited and revised tomorrow, so don't be so quick to hang your hat on yesterdays answers. no big deal there ... if you operate and conduct yourself under that premise anyway (subtle hint to some). secondly, and more important ... we still have a lot to learn, you never stop being a student. all though i have tried using this excuse as i pay to get into some college/high school sporting events, it never seems to fly with the person behind the counter, and they insist i must pay the adult rate, while they give me kudos for the "nice try" ;-)
it will be fun to watch the science play out on this, i will sit back with my bowl of popcorn and enjoy the show. | |
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| Ardi, and the impact on evolution...
Posted: 10/21/2009 3:46:07 PM |
At this point, the only appreciable difference between our ancestors [Ardi] and chimps is that one is bipedal and the other is a knuckle-walker.
This is where it gets really interesting...Ardi had highly flexible wrists, so she was not totally bipedal.
And this is where I am really fascinated...the smaller incisors found in Ardi. (It is not addressed in that article). From what I have read, (admittedly, off of the internet. Why, this is considered a bad thing I am not sure...I do actually read books...only a book about Ardi has not been published yet).
The smaller incisors imply a more sophisticated, (read: possibly peace loving hippie) where, there was not a necessity to bare teeth in order to show dominance and aggression. It might possibly suggest, an advanced form of cooperative effort, within the group.
it will be fun to watch the science play out on this, i will sit back with my bowl of popcorn and enjoy the show.
Do you mind sharing your popcorn? I am betting on science... | |
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| Ardi, and the impact on evolution...
Posted: 10/21/2009 10:00:14 PM | | Evolution has been proven unequivocally to exist. God on the other hand...well, we've been waiting for some proof that animism, totemism, shamanism, polytheism, and monotheism have all been valid for the 1000's of years that people have subscribed to them, but no such luck yet. | |
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| Ardi, and the impact on evolution...
Posted: 10/21/2009 10:10:59 PM | Evolution has been proven unequivocally to exist. God on the other hand...well, we've been waiting for some proof that animism, totemism, shamanism, polytheism, and monotheism have all been valid for the 1000's of years that people have subscribed to them, but no such luck yet.
Note to self...sometimes it helps to actually read the original post, before responding to a thread.
Frogo, thank you for shedding some light on this subject...I greatly appreciate it. | |
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| Ardi, and the impact on evolution...
Posted: 10/22/2009 8:17:15 AM |
Do you mind sharing your popcorn?
*slaps chair seat * pull up a chair wldflower.. the popcorn is hot and buttery, and the beer is cold  | |
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| Ardi, and the impact on evolution...
Posted: 10/22/2009 12:07:33 PM |
*slaps chair seat * pull up a chair wldflower.. the popcorn is hot and buttery, and the beer is cold
*gasps* You have beer too? I am so there...
The discovery of Ardipithecus was NOT a surprise. It was planned.
I don't understand...how was it planned? I understand how it is not a surprise...but planned? | |
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| Ardi, and the impact on evolution...
Posted: 10/22/2009 12:32:09 PM |
Ardi had highly flexible wrists, so she was not totally bipedal
Well, not "totally" bipedal, but "completely" bipedal. That is, it walked fully upright - that's how its hips are arranged. However, the grasping toe and flexible wrist indicate a strong climbing ability. The hip structure is more important because it imposes the main limit on what kind of movement is possible and comfortable. In this case, that's bipedal walking, even though they likely often sheltered or foraged above the ground. We too climb [and swim]. We too are well-adapted to bipedalism. We just phased out some of the features which allowed us to do OTHER things well - like climbing. With Ardipithecus, it's not so much surprising that they had climbing features, as it is that they seem to have come "out of the trees" directly to bipedalism, without a knuckle-walking transition.
I don't understand...how was it planned? I understand how it is not a surprise...but planned?
They wanted older hominine fossils. They looked in older sediments in a region with hominine fossils, and they found older hominine fossils. The researchers were specifically looking for something older than Australopithecus, and by looking in the logical places, they found it. It didn't have exactly the features they expected, but it was what they were looking for, where they expected to find it. | |
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| Ardi, and the impact on evolution...
Posted: 11/2/2009 9:17:25 PM | Mtnwildflower
Antartica:
It has been covered with ice since approximately the beginning of the Pliocene, about 5 million years ago.
It is interesting that protohominids existed in Madagascar in the form of lemurs which were isolated from monkeys and other protoapes.
Antartica was similarly isolated since approx 20Ma.
Is it possible that hominids in the form of Nanderthals evolved separately on Antartica in low light conditions approx 5 million years ago eventually being forced to flee "using their intelligence" from Antartica to Angola Namibia.
Is it possible that Ardipithicus c 5 Ma are not hominids at all and that the real cradle of humanity is Antartica which is now covered in ice. | |
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| Ardi, and the impact on evolution...
Posted: 11/2/2009 9:35:06 PM |
Is it possible that Ardipithicus c 5 Ma are not hominids at all and that the real cradle of humanity is Antartica which is now covered in ice.
Possibly on the first, highly unlikely bordering on ridiculous to the second.
It is interesting that protohominids existed in Madagascar in the form of lemurs which were isolated from monkeys and other protoapes.
Lemurs are a separate branch from hominids. | |
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| Ardi, and the impact on evolution...
Posted: 11/3/2009 12:01:07 AM |
Antartica:
It has been covered with ice since approximately the beginning of the Pliocene, about 5 million years ago.
And has been physically isolated from Africa by extensive and cold ocean for more than 80 million years.
It is interesting that protohominids existed in Madagascar in the form of lemurs which were isolated from monkeys and other protoapes
Lemurs are not "protohominids". They are distant relatives of MOST primates. By definition, a protohominid would be an ape related to the ancestors of gorillas. All other apes [such as gibbons], tailless monkeys [such as baboons and macaques], and tailed monkeys [such as marmosets] are all closer to hominids than lemurs are.
Antartica was similarly isolated since approx 20Ma
As noted, Antarctica has been isolated from Africa for more than 80 million years. Tenuous connections were maintained with Madagascar, Australia, and South America for a time after that. The appropriate fossils all come from Africa.
Is it possible that hominids in the form of Nanderthals evolved separately on Antartica in low light conditions approx 5 million years ago eventually being forced to flee "using their intelligence" from Antartica to Angola Namibia
Technically "possible", but nonsensical. Homo neanderthalensis fossils are mainly found in western Asia and Europe. Fossils of its closest kin and ancestors mainly come from Europe and western Asia. The oldest Homo come from Asia and Africa, and all other hominids are known only from Africa. There is no evidence of H.neanderthalensis [or any Homo] existing 5 MYBP, no evidence of H.neanderthalensis existing in southern Africa, no evidence of any primates in Antarctica, and no indication that H.neanderthalensis was in any way adapted to low light conditions. For that matter, why would there be low light conditions in Antarctica?
Is it possible that Ardipithicus c 5 Ma are not hominids at all
Technically? Yes...but no. They are hominids. They have all the defining features of not only hominids [which includes gorillas and chimps], but of hominines [which excludes gorillas but includes chimps]. In fact, they clearly have more in common with us than with chimps, and are in the right place and time to be ancestors [or cousins of our ancestors].
and that the real cradle of humanity is Antartica which is now covered in ice
Technically? Yes...but no. All evidence points to Africa. No evidence points to Antarctica. Both of these factors are extreme understatements. | |
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| Ardi, and the impact on evolution...
Posted: 11/3/2009 4:37:23 AM | Frogo and Edelwiess
On my kitchen wall is a tree of life poster produced by BBC (The ones who did Life on Earth) and the Open University.
High up on one branch towards the top is the Marsupials linked to Australia
Above that the Euterians (Ardvarks Elephants) associated with Africa and South America.
The branch above are the ungulates like hippopotamus and oryx
Above that are the primates one branch is the Golden Lion Tamarin
Above that is the apes and Lemurs and chimps and humans
Lemurs are exclusively linked to Madagascar due to geographical isolation.
This strongly suggests that lemurs, chimps and humans have major connections to the southern continents and southern Africa.
It is nit picking to suggest that lemurs chimps and humans do not share a common ancestor based in the southern continents
"By definition, a protohominid would be an ape related to the ancestors of gorillas" .I assume this is your definition.
I doubt that any evidence will ever be gathered for any mammal.or marsupial or eutherian from deposits on Antartica because a) it is presntly buried in ice and b) the glaciation will have removed all pliocene deposits including fossils and bones.
That does not mean that life did not exist or evolve there.
Before the glaciation at approx same time as Ardi Antartica was presumably covered in deciduous forests and possibly coniferous forests and ferns.
The area to the leeward side of The West Antartic Range and the Transantartic Range would have been relatively mild climate albeit one that went into perpetual darkness for months of the year. This area had extensive sea inlets and islands providing opportunities for hunter gatherer communities who could store large volumes of food for long relatively mild winters. Intelligent or otherwise.
Since it has been proved by Thor Heyerdahl that long distant ocean travel is possible it is not impossible to envisage a journey by raft from West Antartica to West coast of Africa by hunter gatherers .
Clearly the marsupials, ardvarks, elephants are linked to southern continents so why exclude Antartica.
If you dont exclude Antartica then why exclude marsupials, ardvarks,elephants lemurs from living there in the last 20 million years.
If you dont exclude them then why exclude proto man.
I say "Neanderthals" only because it appears there was a slight variation of man as we know him today known in Europe.
However that does not exclude both homo sapiens and Homo Neanderthals having part of our origins in Antartica as well as Africa.
In fact I doub t that there is any evidence whatever of flora and fauna which lived on the continent of Antartica just before the start of the last glaciation c 5 Ma. That does not mean that it did not exist.
Stating the obvious that "all evidence points to Africa" is simplistic and illogical. | |
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| Ardi, and the impact on evolution...
Posted: 11/3/2009 8:40:08 AM |
Above that are the primates one branch is the Golden Lion Tamarin
Above that is the apes and Lemurs and chimps and humans
There are three possibilities here:
1) The poster is wrong.
2) Your interpretation is wrong.
3) You're mistaking a gibbon for a lemur.
I suspect the last to be the case.
This strongly suggests that lemurs, chimps and humans have major connections to the southern continents and southern Africa.
No it doesn't. It suggests that lemurs are associated with Madagascar, where they have long been isolated, and more advanced primates are associated with Asia, Africa, and South America. There is no connection between lemurs and hominines. The connection is between lemurs and all other advanced primates:
Tree shrews(Tarsiers(Adapids [lemurs and lorises](New World monkeys(Old World Monkeys(Apes)))))
Among the apes [Hominoidea]:
Gibbons(Orangutans(Gorillas(Chimpanzees(other Hominini))))
Lemurs have been genetically and geographically isolated for roughly 60 million years.
Antarctica and Australia were isolated from Africa and South America around 135 MYBP. The most primitive primates appeared around 80 MYBP in North America and Eurasia. There are no primate fossils of any kind in Antarctica or Australia because they had no way to get there. Australia, by the way, didn't suffer continental glaciation. The lack of such fossils on both continents is explained parsimoniously by the animals never being there.
Madagascar has been isolated since roughly 60 MYBP, although the Kergeulen Ridge provided a land bridge to Antarctica and then South America for a time.
"By definition, a protohominid would be an ape related to the ancestors of gorillas" .I assume this is your definition.
It's biological terminology and logic. Other definitions will lead to the same conclusion without explaining the logic, or they will be wrong [like calling lemurs protohominids].
A hominid is a member of family Hominidae [orangs, gorillas, chimps, humans].
A hominin is a member of subfamily Homininae [gorillas, chimps, humans].
A hominoid is a member of superfamily Hominoidea [Hominidae and gibbons].
A "protohominid" would be any animal closely related to the common ancestor of all hominids, which means it would be a hominoid, but not a hylobatid and not yet clearly a hominid.
I doubt that any evidence will ever be gathered for any mammal.or marsupial or eutherian from deposits on Antartica because a) it is presntly buried in ice and b) the glaciation will have removed all pliocene deposits including fossils and bones.
True. Also argumentum ad ignorantiam. All evidence points elsewhere, including the fact that Antarctica and Australia were one continent for a long time, and the latter ALSO lacks primate fossils. Antarctica does have marsupial fossils as old as the earliest primates though. No fossils of primates are likely to be hidden or eradicated. The evidence is that they never existed.
That does not mean that life did not exist or evolve there.
No-one suggested this. Antarctica has many fossils, but no primates, and no reason to expect any.
Before the glaciation at approx same time as Ardi Antartica was presumably covered in deciduous forests and possibly coniferous forests and ferns.
It was tundra. The fossil "trees" are creeping shrubs related to Southern Hemisphere beech trees, similar to the way Arctic shrubs include creeping willows.
The area to the leeward side of The West Antartic Range and the Transantartic Range would have been relatively mild climate albeit one that went into perpetual darkness for months of the year.
Uh...no. It was a refrigerator, surrounded by the Southern Ocean, which did a fine job of making the continent very inhospitable. All of it. Antarctica has been mostly buried in ice for 15 million years, and completely covered for about 6 million years. Pretty unlikely place for a "hunter-gatherer" to evolve.
Since it has been proved by Thor Heyerdahl that long distant ocean travel is possible it is not impossible to envisage a journey by raft from West Antartica to West coast of Africa by hunter gatherers .
Talk about grasping at straws.
Thor Heyerdahl crossed the tropical Pacific, not the stormy and frigid Southern Ocean which is dangerous even to full sized ships. Not to mention no evidence of human habitation, no evidence of suitable climate, no evidence of such a culture or species in Africa, and no evidence of such a species in the time frame you suggest.
Clearly the marsupials, ardvarks, elephants are linked to southern continents so why exclude Antartica.
Because it's NOT clear. Elephants are essentially NORTHERN hemisphere and are not known from any southern continents other than India and Africa, which are connected to the northern hemisphere by land. Marsupials are southern hemisphere, and their fossils are present in Antarctica. What does this have to do with primates, which arose AFTER the breakup of Gondwana, probably in the northern hemisphere?
If you dont exclude Antartica then why exclude marsupials, ardvarks,elephants lemurs from living there in the last 20 million years.
No-one has excluded marsupials but you, based on highly erroneous knowledge of paleohistory. The others ARE excluded by basic biogeography.
However that does not exclude both homo sapiens and Homo Neanderthals having part of our origins in Antartica as well as Africa.
The arguments are essentially the same. The ice block precedes the origin of the entire genus Homo as well as ALL of our known fossil relatives.
Stating the obvious that "all evidence points to Africa" is simplistic and illogical
Given that the argument is based on many lines of evidence, including a diversity of paleontology, paleogeography, and climatology, it is clearly not simplistic. It is also far more logical than positing scenarios which contradict multiple lines of evidence to the contrary. | |
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| Ardi, and the impact on evolution...
Posted: 11/5/2009 7:53:03 AM | Frogo
Uh...no. It was a refrigerator, surrounded by the Southern Ocean, which did a fine job of making the continent very inhospitable. All of it. Antarctica has been mostly buried in ice for 15 million years, and completely covered for about 6 million years. Pretty unlikely place for a "hunter-gatherer" to evolve.
Mostly covered in ice for 15Ma. I take that as fact.
Completely covered in ice for 6Ma. I take that as fact.
Glaciation erodes mountains exceptionally fast. That is also a fact. Previously the mountains were much higher.Fact.
Clearly the Southern Ocean was not interacting with Antartica as it is now otherwise it would be "completely covered" as it is today.
Clearly the Southern Ocean is capable of influencing the climate of Antartica and it is not impossible for Antartic to have been more temperate than it is today.
Do you have access to Ice records for Antartica going back over the last 15 million years?
" Vostok Ice Core
In January 1998, the collaborative ice-drilling project between Russia, the United States, and France at the Russian Vostok station in East Antarctica yielded the deepest ice core ever recovered, reaching a depth of 3,623 m (Petit et al. 1997, 1999). Preliminary data indicate the Vostok ice-core record extends through four climate cycles, with ice slightly older than 400 kyr (Petit et al. 1997, 1999). " NOAA
This suggests the ice record goes back to 400 000 years . Not even half a million years yet I am suggesting habitation of Antartic c 5 Ma by some forms of protohominids.
Where do you get your information on the paleoclimate of West Antartica?
I am not disputing it was a "above the antartic circle" climate with long spells of below the horizon winter.
However Ocean currents may have made it relatively moderate and not quite the refrigerator you describe.
I can not think of an analogy since the Artic Ocean is virtually landlocked and not surrounded in entirity by an ocean which could have been more mild than present effectively keeping the Antartic above freezing.
In the Artic there are no mountain ranges which are at right angles to weather systems
Kamchatka and Alaska are not similar as Kamchatka interupts westward winds blowing of Asia and both are two far south to be anolougous to West Antaric Range or Trans Antartic Range. The Aleutian Chain of Volcanoes is obviously parallel to prevailing winds.
So I remain totally unconvinced about your NPHIA stance. (No ProtoHominids In Antarica)
Clearly any evidence there might be will have been destroyed by any glaciation.
One possibilty remains.
If Global warming continues perhaps the Antartic Glaciers will retreat and the extensive sea coast line in the leeward side of WA Range and TA Range will be exposed.
Someone may find an exposed cave in which there are Australopithicus/Neanderthal type bones alongside lemurs , mammoths sloths and above them on the cave roof pictures of hunting scenes including hunting of sealife from boats. | |
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| Ardi, and the impact on evolution...
Posted: 11/5/2009 7:57:57 AM |
Someone may find an exposed cave in which there are Australopithicus/Neanderthal type bones alongside lemurs , mammoths sloths and above them on the cave roof pictures of hunting scenes including hunting of sealife from boats.
And monkeys *may* fly out of your buttocks. So what? | |
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