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Post by starlightcriminal on Sept 9, 2011 4:55:17 GMT -8
A little dramatic, but here's a recent article: www.usatoday.com/tech/science/story/2011-09-08/2-million-year-old-fossils-raise-hope-over-missing-link/50326266/1Another fascinating look back into time at what may have been around near the divergence of our genus' line and other primates. Of course media wants to dub it "the missing link" because it sounds more exciting and controversial. But just the discovery of a new organism, even an extinct one, is pretty interesting. As always, take it with a grain of salt or two. There's more out there for anyone that is curious, I heard about it on NPR yesterday. |
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Post by wollastoni on Sept 9, 2011 5:11:09 GMT -8
Yes I read about this discovery in August in National Geographic.
It is not an Homo but an Australopitecus. And scientists think his hands made him able to produce tools (before we thought the first primate that made tools was Homo abilis).
Always very interesting to read about our ancestors !
I have always regretted there is only one Homo species living on Earth today. But I am not sure how modern H. sapiens would treat another Homo species... (let's guess the same way we treat Orang Outang in Borneo...)
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Post by starlightcriminal on Sept 9, 2011 5:44:10 GMT -8
Yes, sorry. Mis-thought that when I was typing, A. sebida is the current classification.
I wonder about that too- had there been two contemporaneous species of homo, how would we handle interactions? I considered this when the so-called "hobbit" (H. floresiensis) was found as it was contemporaneous with our species and very recently geologically speaking, just geographically isolated so probably little, if any, contact- possibly our species wiped them out of course, or even more intriguing is that we may have absorbed them as in the case of neanderthalensis.
Sadly, I don't think we would be very nice to them either. We have trouble treating our own species very well, let alone another species and moreover a potential competitor. At best, a zoo exhibit. At worst, extinction policy.
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Post by africaone on Sept 9, 2011 6:51:26 GMT -8
the most actual theory for the modern Homo is that the 2 populations (neanderthalensis and sapiens, longly considered as two distinct sp) mixed and gave the actual Homo. It as been argumented by DNa sequencing of neanderthalensis (compared with ours) It seemed that sexual activity and attraction was sufficient to mix this 2 Homo ssp or sp, despite they differences at the moment they met. Of course I imagine that sexual attraction between an Homo and an Australopithecus (as some lived in same period !) was more problematic  . As some different species of Panthera (or Equus) prooved to be able to mix, why not for Homo ? Don't forget also that it seemed that they (Homo and Australopithecus) didn't live in the same habitat (a restriction to meet !) as it is the case today for different species of apes ! |
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Post by wingedwishes on Sept 9, 2011 7:02:23 GMT -8
Although, there is a big number of people who are unrealistically "rabid" about saving certain species. Think whaling - The protesters go nuts (or what appears to me to be nuts) in their aggressive protesting. I read the article and was very glad to see an Australopitecus articulated so well. The one named Lucy had a few bones that were accused of coming from an area washed down stream and possibly from another specimen. It would be very interesting to read about their tools when found.
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Post by starlightcriminal on Sept 9, 2011 7:12:59 GMT -8
Both sapiens and neanderthalensis are genus homo already, but DNA sequencing does show that we interbred at some point like you mention, as a small percentage of the modern population of humans caries neanderthalensis genes- I think this is also fairly recently characterized, in the last year or two maybe. There were other Homo sp. that were precursors to both neanderthalensis and sapiens though so the mixing didn't give rise to genus homo but did in part contribute to modern sapiens genome. Lots of modern examples of fertile intergeneric hybrids though, so it is an interesting possibility to consider however unlikely it may be. I thought H. habilis was found concurrently with some Australopithecines though, they're both African and are alive at the same time. I guess the question still remains where H. habilis should be Homo or Australopithecus anyway, my understanding is that the wide apparent distribution and morphological variation of habilis leads scientists to believe that Homo is probably paraphylletic in current systematics and needs to be further separated, with habilis likely belonging to Australopithecus or some intermediate as yet undefined genera instead. Correct me please if anyone has more insight, it's been a while since I studied the origins of man so I might be falling a bit behind in this area. Trying not to date myself here.
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Post by starlightcriminal on Sept 9, 2011 7:40:32 GMT -8
I agree, winged. I think we do get a bit defensive about species preservation when the animal strikes a certain cord with us. A butterfly, for example, is very sympathetic somehow. A rare cockroach or mosquito is not, such that if one exists (and it seems likely there are some examples somewhere) I can't even think of it. And we also want to immediately try to draw connections between any vaguely hominid looking fossils and our own origins so it is very wise to exercise restraint when making claims about anything, especially things as ambiguous as a hominid fossil. On the flip side, there is a huge bone of contention (pun intended) related to anything involving the origin of man and the religious components in many societies, so for every real discovery you will find hasty claims about its significance in the story of man as well as people trying to discredit it with no real basis so as to preserve their strict view of the origin of the world. Neither is a very open minded way to approach a discovery of any kind so it causes much counterproductive discussion. As for the story of Lucy, while I do not disagree that the shattered scant remnants of her skeleton are not terribly convincing by themselves (but in the overall set of discoveries related to this topic they become more convincing, no?), they are also not handled by very many people and those that try to make claims about the time line being out of order (as is typical of these kinds of discoveries- you find at least one person for each skeleton practically claiming this exact thing so they say that the world is younger than generally agreed upon) are not in a position to judge on way or the other, not having inspected the site and remains themselves. Most of the time it's either someone who won't believe in an old earth trying to undermine the theory as a whole by picking apart a particular discovery or someone who is a competing scientist that wants to claim their own specimen is older or validate some new theory they are trying to propose which requires dismissing Lucy for one reason or another. I've read most of the recent studies and I personally think that Lucy is as old as they think she is because we don't require only geological context for organic remains- we have bones, they can be individually analyzed and have been, at least for age. Maybe not an individual organism, hard to judge that myself, but certainly at minimum parts of a single species that is very very old and much like a person, only not. That's why always take with a grain of salt, no matter who is spouting the information at you, and especially for this type of topic. Not much gets people going quicker than a discussion of the evolution of man, at least not in the US. Probably because its acceptance currently is inextricably tied to religion and thus politics too. All "no no's" as we have demonstrated ourselves.  |
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Post by pennswoods on Oct 1, 2011 4:36:24 GMT -8
if the photo of the fossilized hand bones are indeed from the specimen under discussion, it looks as if there may be a rather complete set of bones to study. They do use the word "reconstruction" though, as usual, so it makes one wonder. I'm all for hardcore science, always have been, but I do find it humorous when the hominid-diggers find a sliver of a broken toenail, then extrapolate an entire species from it - down to purely speculative details about sociology.
Wasn't the species status of H. floresiensis based solely on morphology? I thought we had established that morphology (things we can see with our eyes) is totally inadequate to differentiate species in our own Genus?
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Post by starlightcriminal on Oct 3, 2011 6:07:02 GMT -8
Look at modern human skeletons with no skin and then look at any of the other hominids- you can see with your eyes very easily that without skin you don't know who is black or white or purple, but you do know who was either extremely deformed or not Homo sapiens. It's not that morphology is useless in distinguishing our own genus, it's that skin color, hair quality, height, weight, distribution for modern humans are all tiny superficial qualities that hide a structure beneath which is morphologically more or less identical from person to person. That is not the case with other hominids and modern humans. It's the emphasis on race that makes it artificial- that's like calling a melanistic rat snake a new species just because the color is different, even though every single other thing is identical. If you skinned that same snake and found that it had a different pelvis, different spinal structure, different dental arrangement, different shaped and size brain cavity, then you have a more convincing set of morphological traits besides "well, it's black." You can't really separate modern humans with morphology beyond that, see why that's a problematic proposition from a purely taxonomic standpoint? And then when genomics confirm that the reason we are morphologically identical almost everywhere besides a handful of variable qualities that fall on a spectrum of skin, eyes, hair, build, etc. you know that distinctions based on race are a thing of the past because they aren't supported by either genetics OR morphology.
It is good to note though that a lot of lumping a splitting occurs with hominids too. We likely have way more named species than we should, they are more often being lumped rather than split as the big craze for hominid specimens has a died down a bit since the initial expeditions excited everyone. There is a bit of the name claim game going no doubt. Hard to say much about a handful of ancient pebbles that are supposed to represent three individuals of a new species, but as a non-expert in hominid fossil ID I accept the possibility that it might indeed be enough if you have the right set of pebbles. I don't disbelieve things just because I am not familiar enough to make a judgment, rather I ask questions.
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