How large was the group of humans that we've descended from?

The accumulation of small heritable changes within populations over time.

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How large was the group of humans that we've descended from?

#1  Postby BlackDog » Feb 28, 2010 8:05 pm

A child would have problems with the Adam and Eve story, with the two brothers and two sisters, or whatever explanation there is in the Abrahamic tradition. There are just too few people involved. I think the species would die out pretty quick.

But how many people where there in the first Homo Sapiens group?

Is the Out of Africa theory a valid one? That explains how we spread, but what I'm interested is the first initial group and perhaps the evolution to the Homo Sapiens.
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Re: How large was the group of humans that we've descended from?

#2  Postby Peter Brown » Feb 28, 2010 8:13 pm

The Incredible Human Journey series by the BBC showed the evidence that Out of Africa theory has a strong body of supporting finds to validate it.

I bought the DVD, but I see it is on youtube if you care to watch it.

A small group of people made the journey, rather than a mass exodus.
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Re: How large was the group of humans that we've descended from?

#3  Postby BlackDog » Feb 28, 2010 8:18 pm

Peter Brown wrote:The Incredible Human Journey series by the BBC showed the evidence that Out of Africa theory has a strong body of supporting finds to validate it.

I bought the DVD, but I see it is on youtube if you care to watch it.



Yes, seen it and loved it :)

But it was a while ago hehe

The reason I ask is because somebody asked me whether the beginning was incestuous, like the Adam and Eve story. I said I'd doubt it because I don't think the number of people were so few. But I'm not sure. From what I have understood is that we interbreed with our predecessors, so its hard to say how many homo sapiens there were.

I was also recommended this video, will check it out soon:

http://www.youtube.com/watch?v=MCayG4II ... r_embedded
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Re: How large was the group of humans that we've descended from?

#4  Postby Mojzu » Feb 28, 2010 8:24 pm

I watched some documentary (Channel 4 or BBC, can't remember which) which explained the out of Africa theory. They suggested a group of around 200 left the African continent and crossed to somewhere such as Saudi Arabia (so a relatively short sea journey). I'm not sure whether it's accurate or not but the program claimed that all humans who are not of direct African descent have genetic markers that link them to a small group of ancestors.
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Re: How large was the group of humans that we've descended from?

#5  Postby BlackDog » Feb 28, 2010 8:32 pm

Mojzu wrote:I watched some documentary (Channel 4 or BBC, can't remember which) which explained the out of Africa theory. They suggested a group of around 200 left the African continent and crossed to somewhere such as Saudi Arabia (so a relatively short sea journey). I'm not sure whether it's accurate or not but the program claimed that all humans who are not of direct African descent have genetic markers that link them to a small group of ancestors.


This?

http://www.youtube.com/watch?v=2mRa9ICp ... r_embedded
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Re: How large was the group of humans that we've descended from?

#6  Postby Peter Brown » Feb 28, 2010 8:36 pm

But I'm not sure. From what I have understood is that we interbreed with our predecessors, so it’s hard to say how many Homo sapiens there were.


Genetic inheritance is not a speciality I could make claims about on its behalf. But I would have to assume mitochondrial Eve chain of humans were one family bond that made it into Europe, there might be other mitochondrial differences which denote other female family bonds that might be a clue to a minimum number of unrelated family groups that left Africa.
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Re: How large was the group of humans that we've descended from?

#7  Postby Peter Brown » Feb 28, 2010 8:44 pm

The reason I ask is because somebody asked me whether the beginning was incestuous


A question that makes my head spin when reviewing it as a Darwinian evolutionary process. Far as DET goes there only has to be the single ‘pure’ finished H. Sapiens that can successfully mate with 99.9% (ballpark figure) ‘pure’ relations to pass on the 100% trait on. Being ‘human’ just spreads like wildfire and there was no need for any incest.
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Re: How large was the group of humans that we've descended from?

#8  Postby Spearthrower » Mar 01, 2010 12:59 pm

BlackDog wrote:A child would have problems with the Adam and Eve story, with the two brothers and two sisters, or whatever explanation there is in the Abrahamic tradition. There are just too few people involved. I think the species would die out pretty quick.

But how many people where there in the first Homo Sapiens group?

Is the Out of Africa theory a valid one? That explains how we spread, but what I'm interested is the first initial group and perhaps the evolution to the Homo Sapiens.



There's a lot of evidence to suggest that an early population of our ancestors bottle-necked at some point a couple of million years ago. Lowest figure I have ever seen was 2000, but it was entirely speculative. The general consensus runs somewhere between 10000 and 20000.

This is quite an old paper now, there might be something a little more current! However, it's interesting because it specifically sets out to address the problems of validating claims about population growth.

http://mbe.oxfordjournals.org/cgi/content/full/17/1/2


Edit: Oh, never seen this one before
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Re: How large was the group of humans that we've descended from?

#9  Postby BlackDog » Mar 01, 2010 1:08 pm

Spearthrower wrote:
BlackDog wrote:A child would have problems with the Adam and Eve story, with the two brothers and two sisters, or whatever explanation there is in the Abrahamic tradition. There are just too few people involved. I think the species would die out pretty quick.

But how many people where there in the first Homo Sapiens group?

Is the Out of Africa theory a valid one? That explains how we spread, but what I'm interested is the first initial group and perhaps the evolution to the Homo Sapiens.



There's a lot of evidence to suggest that an early population of our ancestors bottle-necked at some point a couple of million years ago. Lowest figure I have ever seen was 2000, but it was entirely speculative. The general consensus runs somewhere between 10000 and 20000.

This is quite an old paper now, there might be something a little more current! However, it's interesting because it specifically sets out to address the problems of validating claims about population growth.

http://mbe.oxfordjournals.org/cgi/content/full/17/1/2


Thanks!
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Re: How large was the group of humans that we've descended f

#10  Postby Godless Infidel » Mar 02, 2010 2:29 am

BlackDog wrote:A child would have problems with the Adam and Eve story, with the two brothers and two sisters, or whatever explanation there is in the Abrahamic tradition. There are just too few people involved. I think the species would die out pretty quick.

But how many people where there in the first Homo Sapiens group?

Is the Out of Africa theory a valid one? That explains how we spread, but what I'm interested is the first initial group and perhaps the evolution to the Homo Sapiens.


I'm not sure I understand the Question.

There is no group that can be considered "the first Homo Sapiens". Any population must be of the same species as the generation before and after. The Out of Africa theory does not suggest that all Homo Sapiens left Africa or that they did so as a single group. So how can there be a first group?
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Re: How large was the group of humans that we've descended f

#11  Postby Badger » Mar 02, 2010 3:14 am

Was the "Mitochondrial Eve", our most recent common ancestor, closer in time to us than the first Homo sapiens, or further away?

I read that the group of people who crossed the Bering Straits into the Americas (long after "Out of Africa"), and who gave rise to all the indigenous peoples from the Inuit to the Patagonians, probably numbered only about 30. Evidence: genetic homogeneity/founder effect. Is this true?
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