Bruce R. Fenton Wrote:
> You are right that this, if the academics at
> Dmanisi are correct, should prompt a rethink of
> the entire model we currently call the 'human
> family tree'. I am of the strong opinion that we
> need to completely update our model and do away
> with up to a dozen named species.
Many of these species and sub-species should not have been classified as such in the first place.
> The reality
> appears to be that Homo erectus ranged the planet
> in great numbers, they shared with modern humans a
> high degree of morphological diversity, indeed it
> may have been higher across regions as small
> groups broke off and moved into more isolated
> areas, preserving snapshots of the existing
> diversity at the time of separation.
If so, erectus was a freak of nature all but tortured by the mutations happening in apparently one individual to the next. The problem, which you note, is that this morphological diversity is higher in small populations which if we look at the Dmanisi finds is quite extreme, so much so what is to say that in fact these are not two species/sub-species living together which you note in your very next sentence:
> They also
> would have lived along side hominins
Which also raises an interesting social question as Erectus would have been of an intellectual and physical higher order than Habilis types which suggests the opportunity for subjugation. Thinking of the Dmanisi finds, how do we know Erectus did not bring along some Habilis types along for the ride as underlings of a sort, even slaves?
> exhibited what we think of as archaic
> morphological traits, assuming they could breed
> with these (and we have no evidence against that
> and every reason to suspect they could) we would
> also see individuals with 'extreme' features
> preserved from non-erectus relatives included in
> their lineage. What we call genetic throwbacks.
This does cloud the issue as to what is really what.
> The Dmanisi archaeological site is really out in
> the middle of nowhere, far from any other known
> hominin site that can be thought of as in any way
> related to it in any direct sense.
> Nobody even
> expected to find early hominins in the Caucasus
> region - it was a stunning site and a stunning
> blow for the consensus models.
> 1.8 million years
> ago the most advanced character in the field was
> Homo erectus, and it was supposed to be isolated
> in Africa. The leading experts have examined the
> skulls and concluded that they represent early
> Homo erectus, they do not all agree that these can
> be used to absorb the many named African hominins
> considered to have been co-existing, but they do
> agree these are Homo erectus.
This was the opinion offered by the principle discoverers, repeated as fact in every click-bait web article, but it is not universally agreed they are Homo erectus. Regarding Dmanisi:
"I believe it is a mistake to force it into Homo erectus in the interests of maintaining a linear picture of human evolution. It is actually very distinctive morphologically, and it dramatically underscores that human evolution involved vigorous diversification and experimentation with the hominid potential."
And: there's "no way this extraordinarily important specimen is Homo erectus," I believe he is reffering to skull 5 in particular.
"But Africa is a huge continent with a deep record of the earliest stages of human evolution, and there certainly seems to have been species-level diversity there prior to 2 million years ago, so I still doubt that all of the 'early Homo' fossils can reasonably be lumped into an evolving Homo erectus lineage. We need similarly complete African fossils from 2 million to 2.5 million years ago to test that idea properly."
I recommend reading the whole article: Of heads and headlines: can a skull doom 14 human species?Quote
A newly discovered 1.8 million-year-old skull from Eastern Europe has been pitched as disproving a decades-old paradigm in human evolution.
Its discoverers claim the find sinks more than a dozen species into a single evolutionary line leading to living people. But the new study highlights the propensity of some anthropologists to overstep the mark, interpreting the importance of their finds in a way that grabs the headlines....
Using three-dimensional computing, this new study now also claims the differences in “shape” among the five ancient Dmanisi skulls is no more pronounced than observed between five living humans or five chimpanzees.
This is despite the fact that when the anatomical features (such as the eyebrow bone) of the skulls have been examined by experienced biologists rather than abstract computer methods, researchers like Jeffrey Schwartz have suggested that the Dmanisi sample contains multiple species....
This headline-grabbing approach to publication has become one of the pitfalls of modern academia.
Taxonomy of the Dmanisi Crania, Jeffrey H. Schwartz
> The fact that the
> five skulls are from a single small site and age a
> few thousand years apart makes it unreasonable to
> argue they can be from different populations, no
> matter how different they look, what population
> could they be from?
Why can't they be two species living together?
> We have found nobody else
> nearer to them than Africa - to suggest one or two
> might be another species would be REALLY hard to
> argue - imagine digging up a remote isolated cave
> in lion territory and finding four sets of ancient
> lion skeletons, and then a fifth that looked
> different. If we claimed this additional skeleton
> was a tiger rather than an odd looking lion I
> suspect our lapse in logic would be pointed out by
> all comers. Why would a lone tiger end up so far
> from its territory and be living among lions, how
> could it have ended up in the same grave site
But this isn't how it is at all. They kinda look like lions and in some ways not lions making them rather odd lions in the first place, leaving the possibility they may not in fact be lions, and one in particular seems obviously not a lion. Here is a more accurate scenario-we believe lions lived between time period "X". Here we find an isolated cache of felines that are kind of like lions, or not much at all, in a place and time where there should be no lions. Therefore they are all lions. I forget who said it, and I paraphrase, but I think it is quite apt in that Homo erectus is more a species of time than biological uniqueness, meaning whatever remains are found during the period in which he is believed to have lived are often lumped into his lineage regardless of the facts which if found in another era would be attributed to another species or a new species altogether.
> Could it be just possible another hominin species
> was around, maybe, but all of the leading experts
> that examined the skulls seem to be in agreement
> that they are five examples of Homo erectus
This is simply not true Bruce. These "leading experts" are only the ones who published the paper in the first place which other leading experts, actual leading experts, do in fact disagree. This happens all the time with these discoveries, almost the rule, which has actually become quite a problem particularly in the internet age.
> - no
> matter what any of us may suspect. As I have
> stressed, I can't see a logical argument against
> this finding and I am not qualified to fully
> assess the morphology.
Its quite simple-they are not all the same species which shouldn't be too hard to accept because all models have different hominin species interbreeding with each other. Are we otherwise to assume they just met in back alley caves and screwed then went their separate ways? If they are interbreeding with each other they are co-habitating with each other which I think is exactly what we are seeing at Dmanisi-the first evidence of co-habitation between different hominin species.
> It is no secret that I am very sympathetic towards
> the possibility that early humans, including Homo
> erectus, evolved outside of Africa. Indeed, I
> rather suspect all hominins share a non-African
I think this is where we are heading.
> my suggestion would be they emerged in
> Southeast Asia - where early ancestral primates
> lived over 40 million years ago. The Dmanisi site
> alone is not enough to take down Out of Africa and
> re-position the origin of Homo erectus. The
> counter argument is that we have a long line of
> hominins in Africa, tool using early humans
> existing from 3.3 million years ago. The earliest
> accepted fossils of Homo erectus are in Africa,
> dated to 2 million years ago and of course the
> ancestor of these, Homo habilis (which I call
> early Homo erectus) is present 2.5 million years
I would disagree Homo habilis is early Homo erectus and would actually place him in the Australopithecus line, which he shares much more in common than Erectus, and go so far to say that it is here that the real "missing link" exists, that between Habilis and Erectus. Whether Habilis was even a direct ancestor of Erectus is hotly debated let alone Habilis being early Erectus. Homo Habilis is a good example of how species classification is an utter mess.
> This gives hundreds of thousands of years for
> a group of these beings to make there way out of
> Africa and up into the Caucasus. Much as it
> surprised academics, all they have to do is say,
> "oh well we missed the evidence of yet another
> earlier out of Africa migration".
As you seem to be as well, I am increasingly having issues with the idea that all hominins migrated to Eurasia from Africa at all which the trend seems to be consistently leaning to the other way around.
> Only by presenting hominin sites older than 1.8
> million years that exist outside Africa can that
> argument be countered. It certainly also helps to
> find evidence of very early hominin forms outside
> Africa. For these reasons the best argument for
> the Dmanisi hominins being non-African comes in
> the form of the Masol hominin site in India (2.6
> million years old)
I think the jury is still out on the Masol finds which, though curious, personally I do not find convincing enough to hail it as "proof" of anything. Just more click-bait to me. Also to be considered:
Monkey 'Tools' Raise Questions Over Human Archaeological Record
> and the understood lineage of
> the Homo floresiensis 'hobbits', now that they
> have been fully assessed and attributed direct
> lineage to Homo habilis or a similar archaic
They have not been definitely attributed to Homo habilis and if anything more likely stems from a common ancestor of the two.
The dominant idea has been that H. floresiensis was descended from the larger Homo erectus, an extinct human species that once occupied Asia. Proponents believe ancestors of H. erectus were the first humans to stray out of Africa about 1.8 million years ago.
The theory is that after members of the big-bodied group reached Flores, they gradually shrunk to just 1 metre tall because of the scarce island resources.
Another possibility is that the hobbits were simply short members of our own species – Homo sapiens. The miniature size of the one skull that has been uncovered could be the result of Down syndrome.
Now, the most comprehensive analysis yet suggests the hobbits were, in fact, descended from a mystery ancestor that lived in Africa over 2 million years ago. Some members of this ancestral group remained in Africa and evolved into Homo habilis – the first makers of stone tools. The others moved out of Africa about 2 million years ago – before H. erectus did – and arrived in Flores at least 700,000 years ago....
They found that H. floresiensis was far more closely related to H. habilis than to H. erectus or H. sapiens, suggesting it came from an ancient lineage and shared a common ancestor with H. habilis. This is reinforced by its more primitive, diminutive body type.
> Apart from the logical argument already brought
> up, to which you are raising a finger here, there
> is another good reason why the skulls were
> accepted as a single species (in this case Homo
Were Earliest Humans All 1 Species?
> Oddball Skull Sparks Debate - LiveScience
> The level of variation seen in Homo fossils is
> typically used to define separate species.
> However, the scientists found the level of
> diversity now seen between the five sets of
> fossils at Dmanisi — Skull 5 and the four other
> specimens — is no greater than any seen between
> five modern humans or five chimpanzees.
This is not really true for several reasons and noted by others. First of all, they are just focusing on cranial volume irregardless of morphology of which such diversity is demonstrably greater as to otherwise not be of the same species. While we do find such variance in cranial volume among modern humans, the morphology of the skulls are clearly of the same species, meaning cranial volume is irrelevant to morphology-they are just smaller or larger versions of the same. Also, this argument is one based on the entire sample size of the modern human population yet here we have it within just one population of 5 individuals. Good luck finding this variance by grabbing 5 random people off the street.
Christoph Zollikofer, a neurobiologist at
> the Anthropological Institute and Museum in
> "If you take the biggest skull there and compare
> it to the smallest, the smallest one is 75 percent
> the size of the bigger one, and that's absolutely
> standard in what you would see in modern humans,"
See above. This argument is highly misleading, if not deceptive, as it ignores the morphology which tells quite a different story.
Anyone should be able to look at the differences here, namely the cranial vaults, and understand the differences have nothing to do with cranial capacity as well as the fact the morphological differences are vast. Compare, for example, D4500 to D2700. There is not a chance in hell these are the same species or representative of "variation within a species".
> I am for merging the various Australopithecus
> together into one evolving lineage with extreme
> morphological variation in its midst, I call it
> Homo australopithecus (as tool use goes back at
> least 3.3 million years).
Australopithecus has no business being part of the Homo line for several reasons and is nothing more than a curious partially bi-pedal ape. In my opinion. Early primitive tool use, like the 3.3mya Lomekwi find, should be taken with caution even more so today as we are learning as I noted above that apes make stone flakes indistinguishable from early tool industries.
> It certainly makes most sense to look to
> behaviour, we see some very archaic looking
> fossils at very young sites and as such we can't
> say these people were not fully modern humans.
The morphology of these fossils is what says they specifically are not modern human.
> Clearly they were part of fully modern human
> groups and we must imagine them doing all the same
> activities as individuals with more modern looking
I fail to see how it is "clear" in any regard if not the opposite and do not imagine them doing much if any of the activities of anatomically modern humans beyond the most rudimentary of tool use. Morphological cranial differences are not just "aesthetic", but structural which is some cases limit the possibilities of the higher brain functions allowed by modern human cranial morphology.
> The consensus used to include early dates, the
> 300,000 year old divergence being one. This has
> gone out the window following the Sima de Los
> Huesos genetic study (550 - 765 KYA)
The close affinity with Neandertals, but not with Denisovans or modern humans, suggests that the lineage leading to Neandertals was separate from other archaic humans earlier than most researchers have thought. That means that the ancestors of modern humans also had to split earlier than expected from the population that gave rise to Neandertals and Denisovans, who were more closely related to each other than they were to modern humans. (Although all three groups interbred at low levels after their evolutionary paths diverged—and such interbreeding may have been the source of the Denisovan mtDNA in the first Sima fossil whose DNA was sequenced.) Indeed, Meyer suggested in his talk that the ancestors of H. sapiens may have diverged from the branch leading to Neandertals and Denisovans as early as 550,000 to 765,000 years ago, although those results depend on different mutation rates in humans and are still unpublished.
"Meyer suggested". "Depending on different mutation rates in humans". I wouldn't open that window just yet.
> and indeed
> the University of Indiana comparative fossil
> research that gave the conclusion you are
> referring to when you mention the ancient tooth
> (1,000,000 YA).
It did not give a "conclusion", but rather a "possibility". In their own words:
"If a fossil species is very similar to the expected ancestral morphology, then that species is a plausible ancestor," Gómez-Robles says, though she stresses that such a match is a possibility rather than definite proof of ancestry.
> If you also factor in the
> research at the Denisova cave site, which
> concluded Denisovans were diverging from our
> lineage by 800 KYA, you see why I point to 700 -
> 900 KYA.
I have no idea what you are reffering to regarding the cave site.
2016: "Chris Stringer, a palaeoanthropologist at the Natural History Museum in London, told Science News that the [DNA] results place the Denisovan-Neanderthal divergence at about 450,000 years ago."
Which I suspect is based on the other range of modern human mutation rates which is quite important to recognize the gross imperfection of archeogenetic dating.
Or, again, "Meyer suggested in his talk that the ancestors of H. sapiens may have diverged from the branch leading to Neandertals and Denisovans as early as 550,000 to 765,000 years ago..."
I can see how one could, but not why they would at least not without the caveat this higher date is by far inconclusive at this point and may well not be the case.
> To quote paleoanthropologist Maria
> Martinón-Torres of University College London,
> "researchers should now be looking for a
> population that lived around 700,000 to 900,000
> years ago.”
This comment was made in light of this previous find:Fossil find is oldest European yet.
Some interesting commentary:
"When combined with the emerging archaeological evidence, it suggests that southern Europe began to be colonised from western Asia not long after humans had emerged from Africa — something which many of us would have doubted even 5 years ago," Stringer says.
"There has been controversy over hominids in Western Europe before 1 million years ago, and this should lay that to rest," says Tim White, a palaeoanthropologist at the University of California, Berkeley. But he says he is still unsure whether that population descended from west Asians or not. "There's a lot of time and distance between [the Dmanisi] collection and this one mandible in Western Europe," he says.
> Perhaps, perhaps not. There is evidence that
> suggests we made some good use of the extra time
> You are correct that Blombos cave seem to be a
> place outside of space and time when it comes to
> the continuous story of human evolution and
> migrations. We suddenly find signs of fully modern
> humans just appear there 70,000 years ago
> I tackle this in my book, my
> argument is that modern humans used watercraft to
> reach the coast of South Africa from Australasia
> and/or Southeast Asia. This was a small party of
> refugees escaping from the devastation caused by
> the Lake Toba super volcano, 74,000 years ago. The
> timing fits like a hand in glove, and as we will
> see in a moment so does the artwork at Blombos.
Yes, this is interesting.
> I was not actually thinking of the Blombos rock
> and that early art, but instead an
> almost identical engraving on a shell > from Java, dated to
> over 430,000 years ago and assumed to be produced
> by Homo erectus, my money is on it being made by
> early Homo sapiens, but it exists and somebody
> made it long before that rock in the Blombos
Yeah. I am skeptical of this find but am running out of time to go into. For the readers, keep in mind these shells were discovered in the late 1800's which a modern human looking femur was found in the area along with a fragment of an unusually small skull cap.
Moving a sharp object back and forth which by chance creates regular shapes does not exactly qualify as "art" let alone purposeful intent. Take a sharp rock a move it back and forth along a shell and see what shapes you get.
Whew. Ok, got to get at the day here.
I hope what readers will take away from this exchange is how subjective the "science" of human origins really are which are as a rule based on little more than the interpretation of artifacts and data which can vary wildly between one group or the other relying on the very same data. And above all else, do not take the click-bait headlines at face value as "proof" as more often than not it is merely the opinion of the discoverers who have a vested interest in this interpretation.
Thank you Bruce and again, others feel free to chime in while Bruce is still here.
Edited 4 time(s). Last edit at 11-Jun-17 18:34 by Thanos5150.