Origins of Humanity - skulls found

[Brian G Turner]

The idea that humans originated in Africa, then migrated out, has been a mainstay for theories on the origins of modern humans.

And it just got another boost with a find in Ethiopia that includes the remains of skulls from two adults and a child.

Here's the link:

Oldest human skulls found

Three fossilised skulls unearthed in Ethiopia are said by scientists to be among the most important discoveries ever made in the search for the origin of humans.

The crania of two adults and a child, all dated to be around 160,000 years old, were pulled out of sediments near a village called Herto in the Afar region in the east of the country.

They are described as the oldest known fossils of modern humans, or Homo sapiens.

What excites scientists so much is that the specimens fit neatly with the genetic studies that have suggested this time and part of Africa for the emergence of mankind.

"All the genetics have pointed to a geologically recent origin for humans in Africa - and now we have the fossils," said Professor Tim White, one of the co-leaders on the research team that found the skulls.

"These specimens are critical because they bridge the gap between the earlier more archaic forms in Africa and the fully modern humans that we see 100,000 years ago," the University of California at Berkeley, US, paleoanthropologist told BBC News Online.

The skulls are not an exact match to those of people living today; they are slightly larger, longer and have more pronounced brow ridges.

These minor but important differences have prompted the US/Ethiopian research team to assign the skulls to a new subspecies of humans called Homo sapiens idaltu (idaltu means "elder" in the local Afar language).

The Herto discoveries were hailed on Wednesday by those researchers who have championed the idea that all humans living today come from a population that emerged from Africa within the last 200,000 years.

The proponents of the so-called Out of Africa hypothesis think this late migration of humans supplanted all other human-like species alive around the world at the time - such as the Neanderthals in Europe.

If modern features already existed in Africa 160,000 years ago, they argued, we could not have descended from species like Neanderthals.

"These skulls are fantastic evidence in support of the Out of Africa idea," Professor Chris Stringer, from London's Natural History Museum, told BBC News Online.

"These people were living in the right place and at the right time to be possibly the ancestors of all of us."

The skulls were found in fragments, at a fossil-rich site first identified in 1997, in a dry and dusty valley.

Stone tools and the fossil skull of a butchered hippo were the first artefacts to be picked up. Buffalo fossils were later recovered indicating the ancient humans had a meat-rich diet.

The most complete of the adult skulls was seen protruding from the ancient sediment; it had been exposed by heavy rains and partially trampled by herds of cows.

The skull of the child - probably aged six or seven - had been shattered into more than 200 pieces and had to be painstakingly reconstructed.

All the skulls had cut marks indicating they had been de-fleshed in some kind of mortuary practice. The polishing on the skulls, however, suggests this was not simple cannibalism but more probably some kind of ritualistic behaviour.

This type of practice has been recorded in more modern societies, including some in New Guinea, in which the skulls of ancestors are preserved and worshipped.

The Herto skulls may therefore mark the earliest known example of conceptual thinking - the sophisticated behaviour that sets us apart from all other animals.

"This is very possibly the case," Professor White said.

The Ethiopian discoveries are reported in the journal Nature.

 

[scifimoth]

Very interesting....

 

[littlemissattitude]

...this is definitively the answer to the question of whether Homo sapiens evolved from Africa

Dr Berhane Asfaw

This is an interesting article, an interesting discovery. However, it really amuses me that every time there is a new find, it is hailed by those who found it as the definitive answer to whatever problem they are working on. Wouldn't you think that they would have caught on by now to the probability that there will be - sometime and somewhere - a new discovery that will put everything into question yet again?

As interested as I am in human evolution, I am just as interested in the dynamics that go on between the paleoanthropologists who can never seem to agree on much of anything about their field. For example, I am reading a book right now, In the Footsteps of Eve, by Lee R. Berger, that challenges the generally held idea that Homo sapiens evolved in East Africa, placing that evolution instead in South Africa. Now, I'm not sure I buy Berger's arguments completely, but he raises some interesting questions.

I don't honestly think that, absent the invention of a time machine, we will ever know exactly what happened in human evolution, or exactly when. It is just too difficult to sort out the relationships between different specimens from the fossil record. There is always the mitochondrial DNA approach, I suppose, but there is something about that technique - and I've done a bit of reading on the topic - that just doesn't ring true to me. Not a scientific assessment, I know, but there it is.

 

[Brian G Turner]

Absolutely right - I gave up on the "human evolution" issues once I even cracked the surface. The scarcity of specimens is an absolutely astonishingly unstable ground for making any form of concrete assumptions. And although the paleontologists involved the search would no doubt claim some degree of fluidity, simply raise the issue of interrelationships between various species and you can end up with very definitive answers - often based on a single skull fragment - and so on.

Really, I honestly believe that biology has got so much wrong when it comes to classifying species according to their structural morphology. We know covergent evolution - the appearance of similar features in geographically isolated areas - does happen, and quite widely so. Yet the entire way the biological tree of life is constructed only takes this into account where modern knowledge shows that convergent evolution absolutely can be proven, for example, in comparison to the evolution of New World and Old World species.

And mitochondrial DNA is not the answer - neither is DNA in general. Genetics is finally beginning to realise that it's not what you have, it's the way that you use it - and this is a precise and until recently, totally underestimated (or ignored) point in biology. It's the actual protein complexes, and how they regulate gene experssion, which is going to be the next big growth area of biology.

I'm also under the impression that there are notable assumptions (read: flaws) in using mitochondrial DNA as a primary source for DNA comparison.

All in all, I've been waiting for ages for the biological sciences to catch up and recognise that making assumptions doesn't make for good science - just poor paradigms.

As to how that relates to the evolution of humanity - certainly, we can never be totally sure. However, perhaps there should be far more openess about the actual limitations and room for error.

It's precisely the attitude complained about that put me off from biology. At least physics was open about the mysteries of space and the atom, and so drew myself in much easier. Even still, there are a lot of sloppy assumptions in Cosmology. I try and challenge quite a few in my writing. I'll get onto the biological sciences in the sequel to my work in progress, where I can.

 

[Twelve]

[quote author=brian link=board=16;threadid=362;start=0#msg3030 date=1060587249]
Absolutely right - I gave up on the "human evolution" issues once I even cracked the surface. The scarcity of specimens is an absolutely astonishingly unstable ground for making any form of concrete assumptions. And although the paleontologists involved the search would no doubt claim some degree of fluidity, simply raise the issue of interrelationships between various species and you can end up with very definitive answers - often based on a single skull fragment - and so on.

[/quote]



Exactly. I sometimes wonder what is being taught in schools...facts, or ideas, dreams, and hopes?

12

 

[Brian G Turner]

They are being taught hypotheses - but, unfortunately, ones not necessarily verified. There are limitations to any scientific theory - and in terms of the interelationship between extinct species, there is always going to be a growing room for error.

I guess part of the problem is that we demand answers - possibilities are not good enough - as a species we invariably demand probabilities. Hence every question must have a single answer, rather than multiple possibilities.

Perhaps.

 

[dwndrgn]

I find that the educators don't emphasize the theoretical nature of science enough. They tend to forget that the young minds they are filling aren't already aware that *this* is the most common theory and is substantiated by *this* and *this*. Usually it is just "John Doe discovered this while researching this and so now we know this."

 

[Brian G Turner]

That's what was great about my physics teacher - not every question had an answer. I was very good at finding out whih questions had no known answers.

But in biology, every mystery was washed over. The majority of neurotransmitters, hormones, and enzymes have yet to be understood in any significant way - their effects remain uncatalogued and unknown. Therefore it seems incredible that the field makes so many bold declarations about the nature of neurotransmitters and hormones, in particular. Although there are well studied subjects - such as the sex hormones and endorphins - too many broad statements feel too much like claiming to know how to play Mozart just using a couple of notes.

And as for evolutionary biology - there are so many holes being glossed over. Personally, I think the principle is great, but evolutionary science tends to forget that the actual mechanism, rather than processes of speciation, still remain relatively unknown. Why should certain phenotypes be expressed at all? In what way does the environment actually select for a feature if it's not expressed in the first place? And does speciation occur over long or short geological periods? There are still key pivotal questions which still lack proper answers.

I guess the conflict over Creationism has helped prevent a humility in the discipline, which would likely be otherwise be seen as a fatal weakness by the fundamentalist movement. Unfortunately, in a form of "natural selection" itself, evolutionary theory has developed its own fundamentalists, such as Richard Dawkins, who take the fight beyond Creationism and into the realms of religion and spirituality itself. Such people remain blind to their own flaws and gaps of knowledge. That doesn't make for good science.

A general rant.

 

[Twelve]

Good rant.

We also have to understand that science is very often dictated by society. What society wants to know, or what the people with the money want to know, or what the government wants to prove: these things are often then "proven".

Meanwhile, I believe evolutionary ideas are on the ropes. There's just too much against the idea. Only micro-evolution is feasible; macro-evolution is best left for science-fiction books.

Uh-oh. I better stop, lest someone actually challenge me on my claims. When it comes to hard science, I'm quite out of my league.

12

 

[littlemissattitude]

I think that what those who practice science need to keep in mind is that the scientific method is a tool, not a way to revealed knowledge. Science cannot prove anything; it can only disprove or falsify or, by not disproving or falsifying, tend to indicate that hypothesis might indeed be correct. The only way to prove something scientifically is to test ever single instance of a phenomenon. Can't be done.

Sometimes those who challenge science get the idea that if science can't "prove" something, that means it is not true. I don't know if this is due to poor science education in the schools or to individuals' will to believe what their religions tell them, or a little of both.

Where this comes into play in the debate over human origins is that when a creationist hears that some detail or other of Darwin's theory of evolution has turned out not to be the case, this is taken as a refutation of evolution as a whole. Of course Darwin was incorrect about parts of his theory. That is to be expected; he was working with a lot less sophisticated techniques and knowledge than we have today. Parts of the modern synthesis that is the theory of evolution as it is known today will also turn out to be incorrect. This does not mean that the theory as a whole can be thrown out without another thought, because many aspects of the theory have not been falsified at this point, and don't look as if they will be any time soon.

But the other side of the coin obtains as well. Some of the more radical evolutionists see that there is some evidence to point to the idea that evolution could have taken place without the input of any outside intelligence - God, to many people, especially in the Western world - so they jump to the conclusion that this necessarily means that there is not an entity (or entities) that we understand as God (or the gods). This, in my opinion, is as unwarranted a conclusion as that reached by the creationists that there is no such thing as evolution. Science cannot prove God; science, as I said, is not outfitted to prove anything. On the other hand, science cannot - as much as some scientists (probably not as many as most people would think, based on what we get in the media) would like to have us believe - disprove God either.

So we have a stalemate. Either we have to accept the idea of nonoverlapping magisteria, as presented by Stephen Jay Gould, that science and religion have essentially nothing to say to or about each other. Or else the practitioners of both science and religion have to get over themselves enough to find new ways to talk to each other about the subject matter of both of their disciplines.

My own personal opinion is that science and religion have a great deal to say to each other. And some are beginning the process. I have found the writings of the Reverend Sir John Polkinghorne to be very interesting on these subjects. He is an Anglican clergyman whose first career was as a physicist. He didn't reject the latter when he became the former, and while most of his work is on the more general relationship between science and religion and he doesn't seem to talk very much specifically about human origins, some of you might find his work interesting. I'm not saying that I agree with all of his conclusions; I do admire the fact that he, among some others, is trying to create a dialogue between the two disciplines rather than accepting the status quo of barely disguised warfare that some parts of Christianity and some within science are trying to maintain.

Just my opinion.

Edit: to clarify one sentence.

 

[Dave]

Research confirms theory that all modern humans descended from the same small group of people

Research confirms theory that all modern humans descended from the same small group of people.

Researchers have produced new DNA evidence that almost certainly confirms the theory that all modern humans have a common ancestry.
The genetic survey, produced by a collaborative team led by scholars at Cambridge and Anglia Ruskin Universities, shows that Australia's aboriginal population sprang from the same tiny group of colonists, along with their New Guinean neighbours.

This is proof that everyone, including Australian Aborignes and Pacific islanders came 'out of Africa'.

I just got back the first of my y-DNA test results today that show I am Haplogroup I1c.

Haplogroup I1c is rare in the world, almost zero outside of Europe, but makes up about 20% of Europeans. It is common in Scandinavia, especially Denmark, and in the Scottish and English islands. Basically, I am a Viking!

(Incidentally, there are a number of posts at that phsyorg.com site also disputing evolution again. These creationists are everywhere!)

 

[HardScienceFan]

Here I go again.
First,Kaufman's theories on Olenus evolution,Simpson's on that of Equus,
Brinkmann's theoris on that in Kosmoceras have been proven to be false.
Most theories on evolution revolve around coordinated stasis these days,a concept between punctuated equilibrium and the "regular" idea of evolution.
Large advances in cladistics,vicariance biogeography,increased stratigraphical resolution,morphometric analysis,multivariate statistics, paleoecology, biomechanical theory,ecological theory,ecostratigraphy,new technologies(CT) and simply put,a spate of paleontological dicoveries of an exceptional kind (Doushantuo,Jehol, Herefordshire) have remodeled paleontology and thinking on evolution.There are almost as many theories on evolution as there are evolutionary biologist.Forget teleology,evolution is not directed towars a particular aim.Fred Bookstein pointed out the similarities between evolution and a random walk,in a famous PALEOBIOLOGY article.
On the other hand,the role of heterochrony in evolution has been well established by now,and numerous studies on large samples have shown some form of evolution taking place.Remember,we are dealing with chronospecies here,not biospecies.Numerous examples have been demonstrated of evolution along an environmental gradient in time(the socalled morphoclines).
Evolution is among the most complex and intractable phenomena known to man.Do not be fooled by Creationists.As pointed out elsewhere, the sciences are continually reinventing themselves,throwing out old dogma,bringing in new insights.Do not mistake this process for chaos,or total lack of understanding.Perhaps you do not understand the technology of your television completely,but you ARE able to turn it on.....

 

[mosaix]

Nice post HSF.

I have to admit that I didn't go to the phsyorg.com site to see what the creationists have to say. Sometimes I am worried that I am developing a closed mind, but then again I don't read fairy stories either - life's too short.

 

[HardScienceFan]

I blame a lot on the media*including school textbooks* for popularisations
of science that suffer from the "first glance" effect.Most science doesn't
lend itself very well to cursory examination.National Geographic and Discovery are all very well for the Megastructures and Giant Helicopter fans,but fall way short of the mark on other subjects.
from "amazing animal videos":
"ever since the Mesozoic,50 million years ago,when sea creatures first learned to walk on land"................
I rest my case.
Hang on, I do not.What the eff is going on here,when 4 seconds of Wikipedia
could have shown the makers the idiocy of that statement.
As regards my previous posts:I forgot comparative embryology,molecular genetics*think HOX*,computer modelling, D(eep)S(ea)D(rilling) P(roject)results,taphonomic models ,isotope geochemistry,high resolution stratigraphy,paleoclimatic models,biodiversity research,histology, development of end-member mixing models,INAA,CAI,electron microprobe,flame spectroscopy,Raman spectroscopy,TEM,cathode luminescence techniques,ICP,GRAPE,EDAX,AFTA/FTIR,and probably some more.....

 

[Dave]

I think I touched a raw nerve HSF!

I don't disagree with anything you said, but I was a little amazed at the appearance of Creationists there because I don't believe that the origin of modern humans being discussed is even Evolution - all these populations of humans (categorised by haplotypes) all appeared after the first groups left Africa and are all still homo sapiens sapiens. We are all the same species and genetically are almost identical. In fact, I read a very amusing thing on the Y search website. It said that if you can match a majority of markers with someone you are probably related, if you can match none, then call NASA!

These studies do show how natural selection could act quite quickly, within a few generations, and how that could lead to evolution given geographical barriers - but there are other much better examples of that to use.

In the last few years there have been great advances in y-chromosomal and mitochondrial DNA testing, and the movement and migrations of human populations in the last 190,000 years is very clearly understood.

I don't think those tests are going to help us go further back in time to understand human evolution because of the lack of samples to examine.

And just on 'Amazing Animal Videos' - it sounds like it is something aimed at children. When I was at school quite a bit of the Chemistry and Physics I was taught, especially that regarding atomic structure and wave theory, was just plainly wrong. However, you could never teach a child these complex subjects without some basic understanding first. You don't teach a pre-school child how to write sentences either. I think popularisation of science has a place, but yes, it should step up to something more. I think Creationists are going to believe whatever they believe anyway. It won't matter if they find some popularised science myth or some discredited scientific theory to use in their evidence or not. To fight them is impossible because you are fighting Faith, which I believe is the Richard Dawkins argument.

 

[HardScienceFan]

No man,your post hasn't hit a nerve,because nothing you said would have angered me,it all made sense.I more or less exploded on the spot,so to speak,because evolution and cosmology are very hard concept to grasp,and the media tend to aggrandize and exaggerate "major"discoveries,while most science advances in tiny steps.The scientist themselves are somewhat guilty themselves of this overemphasis.A couple of square mm might contain thousands of microfossils,but hominid fossils are very rare indeed.We don't really have a clue as to what drives speciation,let alone human speciation.And don't get me started on extinction......
Speech, intelligence,bipedal stance,cranial volume,use of artifacts,what makes a human????
Stephen Jay Gould has often warned of the dangers of "storytelling in evolutionary biology,but he had his adversaries too.
Most fossil mammals consist of teeth,anyway.Read Paleovertebrata
or Geobios,and you'll know I kid you not.
Let's say that on human evolution much is suspected,little is known.This probably suits the Creationists,I hate to say.

 

[Spartan27]

No man,your post hasn't hit a nerve,because nothing you said would have angered me,it all made sense.I more or less exploded on the spot,so to speak,because evolution and cosmology are very hard concept to grasp,and the media tend to aggrandize and exaggerate "major"discoveries,while most science advances in tiny steps.The scientist themselves are somewhat guilty themselves of this overemphasis.A couple of square mm might contain thousands of microfossils,but hominid fossils are very rare indeed.We don't really have a clue as to what drives speciation,let alone human speciation.And don't get me started on extinction......
Speech, intelligence,bipedal stance,cranial volume,use of artifacts,what makes a human????
Stephen Jay Gould has often warned of the dangers of "storytelling in evolutionary biology,but he had his adversaries too.
Most fossil mammals consist of teeth,anyway.Read Paleovertebrata
or Geobios,and you'll know I kid you not.
Let's say that on human evolution much is suspected,little is known.This probably suits the Creationists,I hate to say.

Fossil fuels, big bang, evolution....all nice tidey little explanations...talk about blinders on...finite beings believing to understand and explain almost everything with equations that can't be proven in the end. I just don't get it! Talk about faith...that's the very explanation of faith and belief.

 

[j d worthington]

Fossil fuels, big bang, evolution....all nice tidey little explanations...talk about blinders on...finite beings believing to understand and explain almost everything with equations that can't be proven in the end. I just don't get it! Talk about faith...that's the very explanation of faith and belief.

No, it's not faith. It is accumulated evidence -- evidence that has been painstakingly built up over centuries (actually, over millennia, since the beginnings of scientific inquiry go back at least to the Greeks), and which is solidly based on repeatable, verifiable, and falsifiable results of experimentation. "Faith" is something that does not have such a grounding in reality -- even the Bible itself will assert that much. Science, on the other hand, relies on that which can be tested, retested, and re-retested... and the ability to refine (not overturn -- even Einstein didn't overturn Newton; he merely added refinements to our model) for new or contradictory information. "Faith" does not allow for such change. "Faith" is based on authority; science on empirical evidence.

 

[mosaix]

Spartan - you just don't understand science and scientists.

All science wants to do is understand the basic laws of the universe. How the universe is put together and how we got here. If the facts proved that God created us as we stand today then scientists would accept that - they would change their minds according to the facts. People of faith don't.

Do you believe that the Sun goes round the Earth or the Earth goes round the Sun?

The reason that we KNOW that the Earth goes round the Sun as opposed to BELIEVING that the Sun goes round the Earth is that the equations (that you take so lightly) point away from the belief, away from faith and towards the truth - and will continue to do so.

It seems odd now that a few hundred years ago that some people, despite the evidence to the contrary still believed the Sun circled the Earth. But, despite the fact that they believed it, that didn't make it true - regardless of what they had been taught or what the church said.

 

[Spartan27]

No, it's not faith. It is accumulated evidence -- evidence that has been painstakingly built up over centuries (actually, over millennia, since the beginnings of scientific inquiry go back at least to the Greeks), and which is solidly based on repeatable, verifiable, and falsifiable results of experimentation. "Faith" is something that does not have such a grounding in reality -- even the Bible itself will assert that much. Science, on the other hand, relies on that which can be tested, retested, and re-retested... and the ability to refine (not overturn -- even Einstein didn't overturn Newton; he merely added refinements to our model) for new or contradictory information. "Faith" does not allow for such change. "Faith" is based on authority; science on empirical evidence.

I understand the dynamics of what you are saying, JD but I don't think you understand what I am trying to state. There in no reason why both religion and science cannot come together. I guess that's what I am saying.

Just a small comment and question to what you are saying above, where is the empirical data for the big bang theory? And for evolution?