Bruce R. Fenton Wrote:
> First off let me say I do not see the
> contradiction between these two statements:
> "Examination of the recent conclusions associated
> with the analysis of Homo erectus skulls in the
> Georgian Republic confirms that several species of
> hominins in Africa are in fact nothing more than
> expected variance within the greater H. erectus
> "These matters are more complicated than first
> glance. The findings of the Dmanisi site actually
> included the strong suggestion that Homo habilis
> (and similair hominins in Africa) represent early
> H. erectus forms."
> These seem to me just two ways of saying the same
> thing, as best as I can see.
Lol. You are correct, they are not a contradiction- the fault is mine. In my haste I missed the last bit of the second comment. Apologies. Things get muddled when I get to that 5th remaining brain cell. That's ok though because its inspired you to delve into it further.
> My point being that
> most African hominin fossils we know of are, in
> fact, representative of Homo erectus.
> I should
> have added that the this is for fossils dating
> between 2.5 million years ago to around 1 million
> years ago, including European and Asian fossils.
> This provides a new view of our family tree.
Do you think it worthwhile to separate African and Asian Erectus, i.e. Homo ergaster and Homo erectus?
> In response to your comment:
> "Well, it is by no means a “fact” but rather
> opinion to explain [away] the implications of
> having multiple species outside of Africa at such
> an early date."
> It may not be a rock solid undeniable fact (such
> are hard to come by) but I don't agree that this
> latest finding is just given to explain away any
> implications of having multiple species outside of
> Africa early on, even having the same species
> outside Africa at such times is problematic for
> the mainstream.
I fail to see how it falls under the "fact" category at all as to do so changes many of the very "facts" human speciation is built on in which it is these very differences that give classification to many of the different species and sub-species. Its ok to do away with this and chalk it up to variation, but to do so I think means the entire hominin line needs to be reevaluated all the same. To look at the Dmanisis skulls again, this is quite the motley crew:
Homo ergaster cranial capacity is between 700-900cc which I believe only skull 1 of the Dmanisi finds fall in this range at 780cc, whereas all the others are well below, around 600-650cc, with skull 5 at a meager 546cc. This kind of variation is found across other species as well, sometimes greater, including modern humans, so these differences in and of themselves are not enough regardless of the fact most are well below what is to be expected, but in conjunction with these are stark morphological differences which taken together I do not believe constitute variation within a species, but rather different species entirely. Further to consider is that such differences would be expected to be found across a large sample of the population, but this is the population at Dmanisi, all found together, which I do not believe such variance has ever been found in any species before, across the whole let alone within one group. Highly unusual.
> The multiple species model is the
> dominant perspective so few scientists are very
> interested in explaining it away (other than
> perhaps a handful of radicals).
Right, but how does Homo habilis or the like get out of Africa let alone so far out of Africa? It makes no sense unless he (the "Dmanisi Habilis") originated outside of Africa as well which is not something most scientists, at least Out of Africa proponents which is the dominant view, are willing to consider.
> The Dmanisi team
> simply recognised that the morphological diversity
> observed among the five skulls (which are
> universally accepted as being from H. erectus) was
> so incredibly high that there was no longer any
> solid basis upon which to place the multiple
> species model -
But why are they universally accepted as Erectus? This is what I am driving at as the only reason this is offered is to explain why they are all found together outside of Africa. If you took these skulls and placed them in different areas around Africa I guarantee they would not all be considered the same species with some being Habilis or the like and at least skull 1 being Erectus, with some I bet would even be hailed as a "new intermediary species" from Habilis to Erectus.
It is this very morphological diversity that the multiple species (and sub-species) model is founded and if it is to be abandoned for the Dmanisi finds all other species need to be reevaluated as well.
> which is currently based on the
> same level of morphological diversity across
> geographic regions. Morphological diversity alone
> is no longer a sufficient reason to claim multiple
> species if we have real world data telling us that
> Homo erectus were immensely diverse in their
> anatomy and skull morphology.
This is true and many arguments have been made in this regard to other species, namely the myriad of sub species classifications, but also different genus i.e. Australopithecus and Paranthropus.
> What other evidence
> do we have to argue multiple species across
> regions between 2.5 - 1 million years ago?
At this point either the morphology is enough to classify them separately, which personally for some I think it definitely is, or it isn't, though to some degree I would say the tool industry found has some say in this which in Homo erectus's case maybe the qualifier needed to distinguish them is "archulean" and "non-archulean" perhaps.
> As for the discussion about Early Modern Humans vs
> Fully Modern Humans, this is a slippery area. What
> really makes us fully modern humans? Is it simply
> having hugely reduced brow ridges and a more
> gracile form, or is it all the behavioural traits?
> What exactly is the criteria?
Though technically each can be assessed separately, I would say most definitely behavioral though they would appear to be directly related as it is not just how they "look", but rather it is this very morphology that allowed the human brain to develop to achieve such modernity, namely the higher vertical transition of the frontal bone that allowed the frontal lobe to more fully develop. Regardless, it is not our anatomy that sets us apart from other hominins but our behavior, ultimately the definition of what it means to be to be "human". To paraphrase James Shreeve from Neanderthal Enigma, the maddening thing about all species of hominins is that despite their long existence, they did not progress, i.e. build on previous successes, and if anything regressed towards their ends. Homo sapiens were no different as despite "modern humans" having been around for supposedly 200,000yrs he didn't start acting like a modern human until around 45,000yrs ago with the arrival of Cro-Magnon in Europe, who also just so happens to have the tell-tale cranial morphology of what we consider to be fully anatomically modern, something which is not present in Africa before. This means something.
> We now know that the first Homo sapiens, our
> ancestors that diverged away from Neanderthals,
> Denisovans and the shared ancestor, were on that
> lonesome path by around 700,000 years ago.
The consensus so far is sometime between 800,000-300,000yrs ago with recent analysis of a tooth suggesting this may have been earlier:
Much Earlier Split for Neanderthals, Humans?Quote
The new study contradicts this idea. The tooth reconstruction of the last common ancestor of humans and Neanderthals created by Gómez-Robles and colleagues doesn't match the teeth of H. heidelbergensis.
In fact, the researchers found that none of the human species living during the time predicted by genetic data fit the tooth pattern generated by the new study. More than that, "European species that might be candidates show morphological affinities with Neanderthals," Gómez-Robles says, which hints that these humans were already on the Neanderthal side of the split.
This suggests that the last common ancestor of H. sapiens and Neanderthals lived sometime earlier, perhaps as far back as one million years ago.
> In the
> most literal sense then, Homo sapiens have been
> around from perhaps 700,000 years ago, these would
> be the true early humans. When did they become
> early modern humans and when did they become
> modern humans? What is the criteria for these
> stages and are there really such clearly defined
> stages at all?
Without the behavior-what does it matter as otherwise we are no different than any other hominin?
> This all needs rethinking, now that we know our
> line is MUCH older than previously understood (as
> explained in my opening article).
I have to say, as interesting as this may be, I really do not think it matters as whatever our "line" may have been, or how old it may be, it is otherwise no less far removed from fully anatomical and behavioral modern humans as any other species of hominin.
> We also see
> modern behaviour much earlier than believed,
> including use of watercraft and production of
> abstract art.
Can you give examples? I assume I know what you are reffering to. I would address Blombos cave from a previous thread:
The problem with Blombos cave, supposedly occupied from 100,000-70,000ya and again around 2,000-300ya, is that it is wholly unique-nothing like it found before or after anywhere prior to Eurasia c. 40,000ya. Even the style of tool is extremely similar to a kind not found until 20,000ya in Europe. Beads and bone tools found in the cave aren't convincingly found until after 40,000ya as well yet there they are in Blombos cave completely isolated from the rest of the world for 30,000yrs? Here is the "revolutionary" Blombos "artwork":
A bit of a leap with virtually nothing in between from that to this:
Regardless, Blombos cave is arguably the most out of place discovery in the history of anatomically modern humans as before and after, a time spanning at least 100,000yrs, there is nothing but a veritable wasteland of progress with nothing leading up to it and nothing following it for at least 30,000yrs. Even if this discovery is valid, there is a quantum leap between what is found here and what occurs after 40,000ya with nothing to show for it in between which has hardly anything to do with "climate". There is still a large gap between anatomically modern humans and behaviorally modern humans which despite Blombos cave its beginnings still point to the arrival of Cro-Magnon in Europe c. 40,000ya. Whatever progress was made by the Blombos culture it lived and died with them in that cave. And for what its worth, no bones have yet to be discovered there either.
> Conversely we see archaic traits
> surviving much later than previously understood,
> just look at the
> WLH50.html]fossils of WLH50[/url].
This is interesting, but the dating seems rather up in the air so to say it is in fact much later in reality is unknown. It may well not be, but to be fair it does have a close parallel with the Ngandong hominid of Java (Homo erectus), also controversially given a relatively young date. But what these seem to point to is not necessarily later dates for archaic traits in Homo sapiens, but rather a longer existence of Homo erectus, also quite interesting. Also to be considered is the geography of the Pleistocene in these regions were much different with much more land mass. If the artifacts found on Socotra are in fact Homo erectus (based on nothing more than the period of dating), this means they would have had to have traversed open water which conditions to do so would be even more favorable in the Pleistocene to get to Australia. Then you have the Crete finds dated to 130,000yrs which also suggest crossing open water, though the Mediterranean at the time would have been significantly different as well.
> Your intuition on possible problems with some
> aspects of archaeogentics, like dating mutations,
> especially when divorced from physical fossil
> evidence, is very astute. You might find these
> papers of some interest,
> here[/url] and
I will check those out. Thanks.
> Thank you for your points and I do hope you will
> continue to question my claims!
All good. If you were not being challenged I would say you were doing something wrong.
I do not want to monopolize your time so I encourage others to chime in here.
Edited 2 time(s). Last edit at 07-Jun-17 16:24 by Thanos5150.