"Out of Africa" Theory Called Into Question By Originator

Amiga Trombone writes "Christopher Stringer is one of the world's foremost paleoanthropologists. He is a founder and most powerful advocate of the leading theory concerning our evolution: Recent African Origin or 'Out of Africa.' He now calls the theory into question: 'I'm thinking a lot about species concepts as applied to humans, about the "Out of Africa" model, and also looking back into Africa itself. I think the idea that modern humans originated in Africa is still a sound concept. Behaviorally and physically, we began our story there, but I've come around to thinking that it wasn't a simple origin. Twenty years ago, I would have argued that our species evolved in one place, maybe in East Africa or South Africa. There was a period of time in just one place where a small population of humans became modern, physically and behaviourally. Isolated and perhaps stressed by climate change, this drove a rapid and punctuational origin for our species. Now I don't think it was that simple, either within or outside of Africa.'"

Comments

Sounds like a true scientist

[excelsior_gr]

From TFA:

But we're having to re-evaluate [the Out-of-Africa model] now because genetic data suggest that the modern humans who came out of Africa about 60,000 years ago probably interbred with Neanderthals, first of all, and then some of them later on interbred with another group of people called the Denisovans, over in south eastern Asia.

Nice to see some theory re-evaluation in practice. It is the only way to reach the truth.

Re:Sounds like a true scientist

[pr0t0]

This is why science is awesome. The very same guy that advocated the "Out of Africa" theory, circled back in the face of more evidence and is re-evaluating. He's not so prideful to say he was possibly wrong, or partially wrong, or mostly right but needing a few tweaks. He has no reason to feel shame, as generally no scientist should as long as they are doing good work. I applaud Mr. Stringer.

There was a line in the movie "Chain Reaction" where the lead scientist says, "We learned something very important today. We learned another way this doesn't work." or something to that effect. That is also what makes science awesome. Learning what doesn't work is almost as important as learning what does.

Every time I see something like this, I get that "What am I doing with my life?" feeling and start thinking I need to get out of my particular field of IT and start contributing to the body of human knowledge. Computational Materials Science, here I come!

Re:Sounds like a true scientist

[Anonymous Coward]

Although completely unrelated, but a similar circle-back: Roe in Roe v Wade.

Um... no. Not at all. The complete opposite, in fact.

The case of Norma McCorvey (AKA "Jane Roe" of Roe v Wade), is clearly not one of rational reflection upon the discovery of new evidence. From her own words, it is painfully obvious that her radical change of heart was due to a series of emotional appeals impressed upon her while she was in a highly vulnerable psychological state. In desperation, she found religion (after growing up in a non-practicing family, some sources claiming she was actually an atheist) and made many lifestyle choices, including a claim to no longer be homosexual.

I don't want to start an argument on religion or faith or anything, but that kind of extreme conversion in any direction on any topic does not happen rationally without extraordinary evidence (I fail to see any new arguments being introduced since the 70s, but I wasn't able to find any sort of list) and her own comments paint a vivid picture of emotional weakness (as would be expected, given the circumstances).

Re:Sounds like a true scientist

[Internetuser1248]

The politics thing is basically believers in the 'true pure strain' of humans, what the nazis called aryans, are a different species from people of other cultures and nations. Your question was a scienctific one, but it was read through glasses stained with ideology.
I think the real answer is twofold: firstly a single genesis is much simpler and people like to cling to occams razor as though it is a scientific doctrine and not a blunt problem solving rule of thumb. Most of historical theory is rife with the simplest most cut down possible version of events. The second reason is that the idea of conquering and out competing another species appeals more to most people's pride than the idea of interspecies breeding. Neither of these are particular good reasons for supporting a scientific theory but where ancient history is concerned evidence is much scarcer than most people think, so minor influences like this can sway some people.
It is especially ironic that according to most of the paleontologists in the world the purest 'aryan' race is actually the Iranians.

Re:Sounds like a true scientist

[tehcyder]

Are you deliberately trying to wind everyone up?

Look, if the vast majority of scientists believe that a particular theory is the best explanation of something, and it has been tested and not found wanting, then if you want to present an alternative it doesn't mean that you are banned from doing so, it just means you had better have some pretty good evidence.

Also, the people who want to prove that there are different species of human being generally do so on the basis that (a) their species is the best one and (b) all other species are morally, intellectually or in some other way fundamentally inferior.

Power Law in Effect

[Baby Duck]

The problem with pinpointing human origins is we keep digging where 1) human remains are close to the surface, making them easy to dig up, with yearly rains washing away more and more making it even easier, and 2) the conditions for fossilization are highly salient. We very well could have come from environs where fossilization processes are nearly impossible, leaving no trace of our ancestors.

We also like to dig where early humans leave behind stone tools. We don't dig where humans uses wood tools, because they fossilize way less often. It's hard to study what's not left behind! However, it's probable more humans used wood tools earlier and longer.

Re:Power Law in Effect

[nowsharing]

Your points are either incorrect or untestable:

The problem with pinpointing human origins is we keep digging where 1) human remains are close to the surface, making them easy to dig up, with yearly rains washing away more and more making it even easier,

See the cave sites in France. Actually, see cave sites across the world, where excavation involves chipping rock away to find the remains. It's nearer to sculpting and excavation. That's hardly easy, nowhere near the surface, and is standard practice in paleo excavations.

2) the conditions for fossilization are highly salient. We very well could have come from environs where fossilization processes are nearly impossible, leaving no trace of our ancestors.

The burden of proof is on you for this point. You need to give the reasons why you think humans were present in a specific area, and yet their remains (bone, stone, etc) are not present. You may be right now and then, but you can't simply make a broad blanket statement like this. There are hundreds of markers for a human presence that can be examined beyond fossilized remains.

We also like to dig where early humans leave behind stone tools. We don't dig where humans uses wood tools, because they fossilize way less often. It's hard to study what's not left behind! However, it's probable more humans used wood tools earlier and longer.

Humans didn't need stone tools in any areas that had ample bamboo present. It's easier to make and acquire, and just as sharp. However, there is intense work across SE Asia and Indonesia where human remains were found with and without stone tools, probably because bamboo was being used. So again, you're wrong on this point. This is where science takes over. It looks at broad, perhaps logically seeming statements and questions them. Answers come by interpreting evidence. Paleoanthropologists are doing an excellent job, and critiquing them with your own common sense will not lead to you to good answers.

I just watched a 4 season series

[future assassin]

on humans and it showed them coming in on space ships.

Re:I just watched a 4 season series

[Nimey]

Were they shaped like DC-8s?

Re:Misleading headline

[Anonymous Coward]

And on the third day, god created the Remington bolt action rifle, so that man could fight the dinosaurs. And the homosexuals.

Amen.

My guess is that Slashdot editors evolved from a completely different species of proto-human with limited cognitive capacity due to their thick brows and heavy, bony skull plates, which constrained the growth of their brains. This explains many things about their inability to create a useful headline, or edit a summary properly - it's like "infinite monkeys on infinite typewriters," but with way less quality control.

Respect!

[folderol]

For someone to publicly challenge their own theories takes considerable stature.

Re:Duh!

[NatasRevol]

Pro tip:

Phrases like "the earth is trying defend itself" and "starving the earth of resources" put you in the crazies column.

I never understood the traditional species concept

[rrohbeck]

A species is rarely singular, like a line or even like a river. It's more as if there was a continuum, like a flooded plain, and what we see is mainly determined by our own narrow views of organisms (or their remains) in spatial, temporal or cognitive terms. Simple things like the fact that wolves and coyotes are so close genetically that they should be called one species. Or many large cats. Or earlier subspecies of humans.
Paleontologists only see the world as if it was lit up by small flashbulbs every now and then. Yes we've seen a lot of snapshots but how much is that compared to billions of years of evolution all over the Earth?

Re:Duh!

[Anonymous Coward]

Pro tip:

Phrases like "the earth is trying defend itself" and "starving the earth of resources" put you in the crazies column.

But you'd still be qualified to be Director of the White House Office of Science and Technology Policy.

Re:Duh!

[Internetuser1248]

Everyone knows climate change has been going on since the big bang. Doesn't mean that it isn't influenced by humans and it certainly doesn't dispute the fact that it is of concern to modern society. If anything the fact that we have been victims of climate change for millenia reinforces the idea that we should do all we can to research its causes and possible ways to mitigate or adapt to it.

Re:Misleading headline

[russotto]

Reality is more complex than humans just appearing in one location in Africa? That doesn't really question ANYTHING about the theory, but instead just suggests a refinement.

There are multiple theories that really are different

1) H. Sapiens evolved in Africa, travelled from there, overtaking and outcompeting (or outright killing) previous hominids who earlier left Africa.

2) A mostly-modern H. Sapiens evolved in Africa, travelled from there, and interbred with/absorbed existing hominid populations (by some definitions these were also H. Sapiens) who had earlier left Africa. This one isn't so different, but it is different.

3) Multiregional. Earlier hominids (not H. Sapiens) leave Africa in multiple expansions. These various groups evolve, run into each other, and interbreed, and continue migrating (including back to Africa). H. Sapiens emerges as a product of this global interbreeding and evolution. This is obviously a very different theory.

Evidence of modern humans having some Neanderthal and Denisovan DNA casts a lot of doubt on the first theory.