Baffling 400,000-Year-Old Clue to Human Origins

dublinviking

This is for my friend wibbs. Remember when we were talking about migration out of africa, and i told you that people could have migrated to flores earlier than you think? And that there will be lots more surprises in human evolution?

Scientists have found the oldest DNA evidence yet of humans’ biological history. But instead of neatly clarifying human evolution, the finding is adding new mysteries.
More 'Matter' Columns

In a paper in the journal Nature, scientists reported Wednesday that they had retrieved ancient human DNA from a fossil dating back about 400,000 years, shattering the previous record of 100,000 years.

The fossil, a thigh bone found in Spain, had previously seemed to many experts to belong to a forerunner of Neanderthals. But its DNA tells a very different story. It most closely resembles DNA from an enigmatic lineage of humans known as Denisovans. Until now, Denisovans were known only from DNA retrieved from 80,000-year-old remains in Siberia, 4,000 miles east of where the new DNA was found.

http://www.nytimes.com/2013/12/05/science/at-400000-years-oldest-human-dna-yet-found-raises-new-mysteries.html?partner=rss&emc=rss&smid=tw-nytimes&_r=2&

Wibbs

dublinviking wrote: »

This is for my friend wibbs. Remember when we were talking about migration out of africa, and i told you that people could have migrated to flores earlier than you think?

IIRC The issue came with you not having a good grasp of the various stages of human evolution and the various species/sub species within it.

And that there will be lots more surprises in human evolution?

That's nigh on my mantra at this stage.

Cool result from the Spanish fossils. It's thought provoking, but hardly that baffling really(and nada to do with out of Africa timeframes). Denisovans and Neandertals had some genetic interchange later on where territories overlapped(and the former also seem to have got it on with an even older lineage, possibly Erectus or an entirely unknown species). They're more related to each other than we are.

A simplistic explanation for the findings would be that the Spanish Homo Heidelbergensis are the "original" and that some of their descendants moved out from Europe making it to Asia "becoming" the later Denisovans. The Heidelbergensis that stayed in Europe "became" Neandertals. Local environmental pressures changing their DNA over time making them more distinct. This can happen quite quickly. EG we know from historical records that Saxons emigrated to and settled in England in quite large numbers, yet today their genes are rare in the modern population and the female lines have all died out and that only took a thousand years. Modern human genes have changed more in the last 15,000 years than they had in the previous 40.

Climate change in Europe would have been a very strong selection pressure. Neandertals were a very small presence in the landscape and because of this show a lot of apparent inbreeding. Mate selection at times was difficult. This would concentrate some genes over others, making them more genetically distinct(and narrow).

What might be more interesting as a take is that European Heidelbergensis(Erectus version 1.5) rather than evolving in Europe or Africa from Erectus actually arose in Asia first. Then migrated to Europe over the many centuries, becoming Neandertals along the way, leaving their ancestors to evolve into later Denisovans in Asia. Actually I'll predict that this is the case and this is why we find more ancient possibly Erectus DNA in the Denisovan folks.

From the article:
Denisovans were believed to be limited to East Asia, and they were not thought to look so Neanderthal-like.
Eh we have a toebone and a tooth IIRC. Both of which are robust. Either way what they may have looked like is serious guesswork and supposition. Given the bones are robust, much more robust than moderns, they're more likely to look like Neandertals than not. Add in this latest genetic evidence and it's even more likely they did. The Spanish bones have courted controversy for quite a while over who precisely they represent and what age they actually are. Are they earlier Heidelbergensis, or are they later Neandertals? This finding seems to nail it to the former.

Limited to East Asia? Again we have two tiny samples from just one cave. No way in hell can you say that was their range. It may have been their extreme eastward range, even a one off individual fluke as much as the centre of their range. Extrapolating from one(or two) from the same place is again supposition of the highest order.

On the local archaic humans in Asia, there are a number of interesting bones from that area. Some look "Neandertal like" though different enough to be diagnostic, maybe our Denisovan lads and lasses. It could easily be yet another pre modern human population.

I think(and it's just my humble) that much of the issues that arise in archaic human genetic stuff is us. Modern humans are quite narrow genetically. Not as narrow as Neandertals but we're pretty closely related to each other and the further we go from Africa the more related we become. A band of chimps in the Congo separated from another band by a river and a few miles are more diverse than we are, but they're still chimps, one species. This I think can make us look at previous humans as being more like us and when we find genetic variation may jump to the conclusion that there were loads of different species around. It might be more like the chimp model. Same species with way more local genetic variation than modern humans possess.

We see similar even in the describing of the fossil record. A slightly different jawbone and immediately it's a "New human species". The idea of natural diversity* is often ignored for the sake of a new discovery someone can put their name to.



*within some limits of course. EG no way in hell would anyone with even a smattering of anatomical understanding think a Neandertal was a modern human. They have measurements way outside the range of modern humans. Show a cast of a Neandertal skull to a modern day doctor and he'd spot the differences from a room a way.

dublinviking

All I am saying is that out of africa, if it ever was out of africa, could have started much earlier, but we have not found archaeological artifacts yet to prove it. Our genes are older than the oldest "modern" human bone. I can bet that the out of africa time frame will change within next 10 years. Nothing is 100% certain.

I have posted this article to show you that you can not be so sure in what you learned at school. New things get discovered.

The distribution of denisovians was certain until now. Now we are back to square one about the distribution of Eurasian humans. Evolution of modern man was certain until gerogian sculls were found. Now we are back to square one. Neanderthals, Denisovans and modern humans were different species, until intermixing was discovered. Now we are back to square one. Neanderthals were considered inferior to modern humans and that was taken as a reason for their disappearance, until we found that their technology was at least as good as modern human if not better. Now we are back to square one.

For me this is fun. It is like Forest Gump says: life is like box of chocolates. You never know what comes next...:)

dublinviking

O and have a look at this

The Toba supereruption was a supervolcanic eruption that occurred some time between 69,000 and 77,000 years ago at the site of present-day Lake Toba (Sumatra, Indonesia). It is recognized as one of the Earth's largest known eruptions. The Toba catastrophe hypothesis holds that this event caused a global volcanic winter of 6–10 years and possibly a 1,000-year-long cooling episode.
The Toba event is the most closely studied super-eruption.[2][3][4] In 1993, science journalist Ann Gibbons suggested a link between the eruption and a bottleneck in human evolution, and Michael R. Rampino of New York University and Stephen Self of the University of Hawaii at Manoa gave support to the idea. In 1998, the bottleneck theory was further developed by Stanley H. Ambrose of the University of Illinois at Urbana-Champaign.

http://en.wikipedia.org/wiki/Toba_catastrophe_theory

Lake Toba (Indonesian: Danau Toba) is a lake and supervolcano. The lake is 100 kilometres long, 30 kilometres wide, and up to 505 meters (1,666 ft) deep. Located in the middle of the northern part of the Indonesian island of Sumatra with a surface elevation of about 900 metres (2,953 ft), the lake stretches from 2.88°N 98.52°E to 2.35°N 99.1°E. It is the largest lake in Indonesia and the largest volcanic lake in the world.[1]

http://en.wikipedia.org/wiki/Lake_Toba

Do you think that one of the biggest super volcanic explosions could have sank the bridge between the mainland and Flores? Look at the time frame....

Tordelback

dublinviking wrote: »

Evolution of modern man was certain until gerogian sculls were found. Now we are back to square one. Neanderthals, Denisovans and modern humans were different species, until intermixing was discovered. Now we are back to square one. Neanderthals were considered inferior to modern humans and that was taken as a reason for their disappearance, until we found that their technology was at least as good as modern human if not better. Now we are back to square one.

I'm not sure any of these statements count as 'square one'. Knowledge builds by increments, the data we had for all these hypotheses still exist, much of what we know is unchanged, but new data mean new hypotheses, to which all scientists and interested parties say 'Yay!'.

Thee is very little as exciting and dynamic as the field of human evolution at the moment, but we don't have to start from scratch every time we get new results to ponder.

dublinviking

When i say square one i mean what we thought was certain becomes uncertain. Of course we don't go back to zero. But we do go back to drawing board...we know that there was some migration out of africa. Did it start 100,000 years ago or 150,000 years ago is the question. We now know that there was a back migration as well. Neanderthal genes were found in african population. So, back to drawing board...

Wibbs

dublinviking wrote: »

All I am saying is that out of africa, if it ever was out of africa, could have started much earlier, but we have not found archaeological artifacts yet to prove it.

Which "out of Africa"? There were a few that we know of. Even among modern humans there were at least two. The first was when we met our Neandertal cousins first and had kids with each other, then the climate changed and we ran back to Africa, they stayed. Later on some of our lads decided they'd like a ski holiday and came back into Europe and stayed. That's outside us going into Asia a couple of times too. It's highly likely there have been back and forth movements into Eurasia since Erectus came along(and possibly before).

The distribution of denisovians was certain until now.

No it was not, except in some sources in the media. One cannot, with a straight face, suggest any sort of distribution of a species by three tiny remains in a single cave. Indeed one of the samples looked more like a Neandertal genetically.

Now we are back to square one about the distribution of Eurasian humans.

We never left "square one". This new research adds to the mosiac of what was going on, but tells us little of the distribution of the later folks we call Denisovians.

Evolution of modern man was certain until gerogian sculls were found.

God. We've been down this road before. No it was not. The Georgian skulls were known from the get go to be the earliest known examples outside of Africa of Homo Erectus. The apparent surprise(though not to me) was the diversity these individuals showed within the same species and timeframe. That's it. End of. No rewriting of the origins of modern man, instead a rewriting on how to classify Erectus as a species and to dial back the "oh wow a new species, can I name it?" of the past, just because a slightly differently shaped jawbone showed up(though that's still way too prevalent IMH).

Neanderthals, Denisovans and modern humans were different species, until intermixing was discovered. Now we are back to square one.

Nope again. They were seen as subspecies of each other, originally thought to not have interbred. Denisovian DNA was sampled and sequenced very soon and showed they were in us and had Neandertal mixture too.

Neanderthals were considered inferior to modern humans and that was taken as a reason for their disappearance, until we found that their technology was at least as good as modern human if not better. Now we are back to square one.

*sigh* It's not nearly that simplistic. Yes in the early 20th century they were seen as the crude "apeman", the missing link, but by the 1950's(and before) this view was being challenged. Secondly, while their lithic technology(stone tools and such) was complex, required some skill to learn and was as efficient as modern humans of the time and helped them survive in conditions for 200,000 years that would kill Bear Grylls in minutes, their overall toolkit was lacking. They used wood as a material(and watch that area climb in finds), but their use of bone was near absent. They had no needles, so fitted clothing was out. They had no distance weapons/hunting gear. Their hunts were close in and brutish and with a high chance of injury. We had throwing spears. They had early on but dropped the tech. We also had spear throwers and flighted mini spears to increase range.

Most of all, our biggest tool in the toolbox, we had a very different culture and mindset. We had art, we had trade, we had mythology and all that. They sometimes very rarely(and it's contentious) had inklings of that, but we were like a space alien landing compared to all previous humans. The amount of all art/cultural "stuff" made before us, by ANY humans going back a million years would comfortably fit in a laptop bag. We come along and just a square meter of a Spanish cave would increase that by a hundredfold.

dublinviking wrote: »

Do you think that one of the biggest super volcanic explosions could have sank the bridge between the mainland and Flores? Look at the time frame....

Certainly possible, but the scars of that would remain on the seabed in the area and I've read no such findings and the researchers would have looked at that data early on, but yep it's possible.

dublinviking

Which "out of Africa"? There were a few that we know of. Even among modern humans there were at least two. The first was when we met our Neandertal cousins first and had kids with each other, then the climate changed and we ran back to Africa, they stayed. Later on some of our lads decided they'd like a ski holiday and came back into Europe and stayed. That's outside us going into Asia a couple of times too. It's highly likely there have been back and forth movements into Eurasia since Erectus came along(and possibly before).

Ok so we agree on something. Good.

One cannot, with a straight face, suggest any sort of distribution of a species by three tiny remains in a single cave.

Yet scientific journals did exactly that.

We never left "square one". This new research adds to the mosiac of what was going on, but tells us little of the distribution of the later folks we call Denisovians.

My point exactly.

*sigh* It's not nearly that simplistic. Yes in the early 20th century they were seen as the crude "apeman", the missing link, but by the 1950's(and before) this view was being challenged. Secondly, while their lithic technology(stone tools and such) was complex, required some skill to learn and was as efficient as modern humans of the time and helped them survive in conditions for 200,000 years that would kill Bear Grylls in minutes, their overall toolkit was lacking. They used wood as a material(and watch that area climb in finds), but their use of bone was near absent. They had no needles, so fitted clothing was out. They had no distance weapons/hunting gear. Their hunts were close in and brutish and with a high chance of injury. We had throwing spears. They had early on but dropped the tech. We also had spear throwers and flighted mini spears to increase range.

The problem here is that we are partially them. You are constantly forgetting that. Throwing spears are useless in forests.

The oldest excavated bone tools are from Africa, dated to about 1.5 million years ago. It is widely accepted that they appeared and developed in Africa before any other geographic region. A very famous excavation of bones tools is that of the Blombos Cave in South Africa. A collection of twenty-eight bone tools were recovered from 70 thousand year old Middle Stone Age levels at Blombos Cave. Careful analyses of these tools reveal that formal production methods were used to create awls and projectile points.[3]
Bone tools have been discovered in the context of Neanderthal groups as well as throughout the development of modern humans. Archaeologists have long believed that Neanderthals learned how to make bone tools from modern humans and by mimicking stone tools, viewing bone as simply another raw material. Modern humans, on the other hand, took advantage of the properties of bone and worked them into specific shapes and tools.
A recent discovery of specialized bone tools at two Neanderthal sites in southwestern France brings to light the idea that Neanderthals may have actually taught modern humans how to make specialized bone tools. The uncovering of lissoirs (“polishing stones”) at these sites is significant as they are about 51,000 years old, predating the known arrival of modern humans to Europe.[4]

http://en.wikipedia.org/wiki/Bone_tool

So not true that neanderthals didn't use bone tools.

Also when you get to 60,000 bn, there is very little difference in tools between "us" and "them". It is actually difficult to distinguish them. At least according to sources i read which could be wrong of course.

Most of all, our biggest tool in the toolbox, we had a very different culture and mindset. We had art, we had trade, we had mythology and all that. They sometimes very rarely(and it's contentious) had inklings of that, but we were like a space alien landing compared to all previous humans. The amount of all art/cultural "stuff" made before us, by ANY humans going back a million years would comfortably fit in a laptop bag. We come along and just a square meter of a Spanish cave would increase that by a hundredfold.

You are really biased and still live in the world of "us" and "them" which frankly is the world of the past. Every new discovery is proving you wrong.

Wibbs

dublinviking wrote: »

Yet scientific journals did exactly that.

And it was clearly daft if any did. You quite simply can't extrapolate from one example.

The problem here is that we are partially them. You are constantly forgetting that. Throwing spears are useless in forests.

Partially them. Your example shows this up. It seems way back in their past they had used spears more suited to throwing but evolved the close in ambush type attacks useful in forested regions. Then as the forests declined they didn't adapt back, or quickly enough. In regions were moderns humans overlapped with Neandertals we outcompeted them with throwing spears. And yes you are correct re forests and throwing spears however many open areas remain in such environments, waterholes and swampy areas where Neandertal hunting and butchery practices have been excavated(Lynford Quarry in the UK as an example), sites where throwing spears would have had an advantage, yet they didn't avail of them.

http://en.wikipedia.org/wiki/Bone_tool

So not true that neanderthals didn't use bone tools.

Read the page again and read further on Neandertal use of bone. It shows up very late and in contexts that are controversial. Even if they are Neandertal sites as the wiki points out it looks like they copied us rather than come up with the tech themselves.

Also when you get to 60,000 bn, there is very little difference in tools between "us" and "them". It is actually difficult to distinguish them. At least according to sources i read which could be wrong of course.

I dunno what sources they were, but at that time it's actually quite easy to spot the differences. You have to go back nearer 100,000 years before it's difficult to tell. EG the Mousterian technique used by Neandertals for a couple of hundred thousand years until their demise was only used by moderns in north Africa for a short period of time. In Europe modern human contexts don't show this technique. When such items are found it's seen as a clear indicator of Neandertals. Again this shows differences between us. As I said this particular technique lasted for a very very long time, with very little evolution or change(exceptions like the shortlived Quina industry and some rarer examples of blade production aside). They were'nt fools, they did adapt at times, but when fully modern humans from 50 odd 1000 years onwards come along they change and adapt far more quickly and those ideas spread.

You are really biased and still live in the world of "us" and "them" which frankly is the world of the past. Every new discovery is proving you wrong.

With respect I've been proven far more right about them over the years than you have and know far more about them and other archaic humans than you clearly do.

If you had read any of my witterings about Neandertals you'll see I have huge respect for them. I always considered them fully human and considered them a clever bunch of folks who were more inventive than we usually give them credit for. Hell I was predicting they'd find we mated with them before it came out and on this very site too. A few of my other ramblings have turned out on the ball too, so it's far more the case of each new discovery proving me right.

robp

dublinviking wrote: »

Yet scientific journals did exactly that.

I am not sure if that is true. The original Nature papers where it was published were very conservative. They did claim to have a new species. They simply designed the population 'Denisovians' and suggested they may have been widespread in Asia during the Late Pleistocene epoc. When ever I hear geneticists talk about this find they stress that the presence of Denisovian DNA in Melanasia shows that Denisovian range is unknown.

dublinviking wrote: »

Ok so we agree on something. Good.
http://en.wikipedia.org/wiki/Bone_tool

So not true that neanderthals didn't use bone tools.

Clear evidence of neanderthal bone tools are very rare. Usually purported bone tool are not verifiable. Recently some bone lissoirs have been found in France which are verifiable but they are super late. Although they pre-date the current known date of the appearance of modern humans and its not impossible that these tools were copied from very early moderns that have not been spotted yet. The earliest moderns in Europe are very ephemeral in the archaeological record.

dublinviking wrote: »

You are really biased and still live in the world of "us" and "them" which frankly is the world of the past. Every new discovery is proving you wrong.

There still are huge gaps in our knowledge but there are hints of major behavioural differences between the populations 1) bone industries, 2) diet e.g. rarity of fish in diet, 3) symbolic behaviour, 4) lithic technology

These differences may fade with news discoveries but as of 2014 they occur.

dublinviking

I dunno what sources they were, but at that time it's actually quite easy to spot the differences.

I can't remember, but it was about modern and neanderthal tools in middle east after 60,000 bn. Apparently it is impossible to spot the difference.

If you had read any of my witterings about Neandertals you'll see I have huge respect for them. I always considered them fully human and considered them a clever bunch of folks who were more inventive than we usually give them credit for. Hell I was predicting they'd find we mated with them before it came out and on this very site too. A few of my other ramblings have turned out on the ball too, so it's far more the case of each new discovery proving me right.

I am sorry i didn't read your "ramblings". Maybe we would have avoided stupid arguments, as it seems that we are more or less agreeing on everything.

As for adoption to new environments, that is granted the most important thing that made "us" the rulers of the earth. But this change in adaptability, smartness, inventiveness happened suddenly, and only after us and them started living together or at least side by side? Why? Did we learn from each other? Or was there additional intermixing combined with specific environmentally induced epigenetic changes, which produced the the lucky super new human, the good old Cro Magnon? This is a big question. I believe that there is more to this story to come yet. And its going to be fun.