Races.

The science or study of primitive societies and the nature of man.

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Digit
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Races.

Post by Digit » Thu May 14, 2009 12:34 pm

The programme on Brit TV about a single tribe colonising the world has started me thinking. 8)
According to the programme there were/are 14 distinct racial types in Africa, now this tribe crosses into Arabia and begins to spread. Theoretically their DNA will be slightly different to the other groups left behind so they will be carrying with them less than the full DNA spectrum.
The tribe finds their Eden and settles down, till later some get itchy feet and move on. If this is repeated often enough each group will begin to develop a slightly different DNA profile and herein lies the basis of the various races?
For many millenia there will be little interbreeding between the groups and the racial differences will become fixed as random mutations and whatever else influence their DNA profile has an effect.
Logically random mutations will have a relationship to the size of the population, the higher the population the greater the number of mutations?
Hence evolution will accelerate?
But today we are more mobile than at any time in our previous evolution, but do we interbreed fast enough to prevent what would otherwise seem the logical outcome, that the races are a step along the road towards speciation?

Roy.
First people deny a thing, then they belittle it, then they say it was known all along! Von Humboldt

Rokcet Scientist

Post by Rokcet Scientist » Thu May 14, 2009 2:25 pm

Could be.

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Post by Minimalist » Thu May 14, 2009 3:58 pm

Darwin also requires "isolation."

That we do not have today.
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Post by Digit » Thu May 14, 2009 4:05 pm

That was one of my points Min. In the majority of the world's population we have just that.
If you had a row of houses with a Muslim in one, a Hindu next door, a Rastafarian, then a Jew, next door a Catholic, followed by an Anglican, from the inter breeding view point they are isolated. What chance is there of a mainland Chinese breeding with a Scandinavian?
We are isolated by geography, nationality, culture and religion.

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Post by Minimalist » Thu May 14, 2009 4:15 pm

I see white guys with Chinese girls all the time.

The point might have been more valid before modern transportation but, even then, colonialism, migration, slavery, and warfare did their part to spread the gene pool.

There was a recent special about the discovery of new fish species in the Congo River. Apparently, the isolating factor is the extraordinary depth of the river at various points which provides a haven from the raging current above. Interesting shit but some of those fish were definitely weird.
Something is wrong here. War, disease, death, destruction, hunger, filth, poverty, torture, crime, corruption, and the Ice Capades. Something is definitely wrong. This is not good work. If this is the best God can do, I am not impressed.

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Post by Digit » Thu May 14, 2009 4:37 pm

I see white guys with Chinese girls all the time.
Granted, but in the States Min, and I doubt that interbreeding is taking place fast enough to have any effect.
Put it another way Min, do you think that the mixing of genes between Scandinavians and Chinese is taking place fast enough to make an difference in altering the races, I think not.
To have any effect on the 'Chinese' DNA I would think that millions of Chinese would have to interbreed with the other races.
When you look at the number of children some races produce per family I suspect that that the racial differences are being 'fixed' faster than ever.

Roy.
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Post by Minimalist » Thu May 14, 2009 6:36 pm

I accept that core populations tend to breed among themselves more so than interbreeding. As China throws off its insular, communist past and becomes a major international player I would expect those contacts to increase.

However, I'm far from convinced that these racial "characteristics" developed in the 70,000 year period after Toba, which is what the OOA crowd insists upon. It just doesn't seem long enough whereas a human population which derives from HE, 1.4 million years ago does seem to be long enough.
Something is wrong here. War, disease, death, destruction, hunger, filth, poverty, torture, crime, corruption, and the Ice Capades. Something is definitely wrong. This is not good work. If this is the best God can do, I am not impressed.

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Post by Digit » Fri May 15, 2009 3:11 am

However, I'm far from convinced that these racial "characteristics" developed in the 70,000 year period after Toba, which is what the OOA crowd insists upon
Couldn't agree more Min. At the moment the programme, though interesting has a few holes in it.
I read an article 'tother day for schools and they are still teaching that HE, 'either died out in Asia or retreated back to Africa'.
I am researching HSS in China at the moment and there are some claims to him being there some 30000 yrs before the programme reckons he left Africa.
And what about Mungo man, if the dating is correct OOA rather than regional development looks decidedly shaky.

Roy.
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Post by Minimalist » Fri May 15, 2009 9:12 am

There's another point about Darwin's theory though which bothers me, (to go back to your original point, for a moment). Just having an isolated population is not enough....you need mutations which give an organism more of a chance to reproduce. Thus the question presents itself as: Do mutations occur more often in populations which have been inbreeding in a small gene pool?

While I agree that there a billion Chinese and almost a billion Indians there are dynamic factors in those populations that mix the gene pool up. In China there has been a trend for farmers to move to the cities looking for work.

Might not a group like the Mandaeans in Iraq ( a small, insular, religious group) be a better laboratory for your idea?
Something is wrong here. War, disease, death, destruction, hunger, filth, poverty, torture, crime, corruption, and the Ice Capades. Something is definitely wrong. This is not good work. If this is the best God can do, I am not impressed.

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Post by Digit » Fri May 15, 2009 10:31 am

If 'random' changes in DNA are random in the mathematical sense you could not predict who it would effect, but you should be able to calculate the number of mutations per generation, per thousand years, or what ever, per 100000 population. If that is so the larger the population the greater the number of mutations in a given time.
I have read that human evolution is speeding up so my suggestion does appear to make sense Min.
Against that is the point that the longer any such mutation would take to reach the 'tipping' point, as in a pandemic.
Just musing actually Min.

Roy.
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Post by Minimalist » Fri May 15, 2009 10:54 am

Isn't that what this board is here for?
Something is wrong here. War, disease, death, destruction, hunger, filth, poverty, torture, crime, corruption, and the Ice Capades. Something is definitely wrong. This is not good work. If this is the best God can do, I am not impressed.

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Post by Digit » Fri May 15, 2009 11:45 am

DNA links Aborigines to African walkabout
7 May 2007

New research confirms theory that all modern humans are 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.

The research confirms the "Out Of Africa" hypothesis that all modern humans stem from a single group of Homo sapiens who emigrated from Africa 2,000 generations ago and spread throughout Eurasia over thousands of years. These settlers replaced other early humans (such as Neanderthals), rather than interbreeding with them.

Academics analysed the mitochondrial DNA (mtDNA) and Y chromosome DNA of Aboriginal Australians and Melanesians from New Guinea. This data was compared with the various DNA patterns associated with early humans. The research was an international effort, with researchers from Tartu in Estonia, Oxford, and Stanford in California all contributing key data and expertise.

The results showed that both the Aborigines and Melanesians share the genetic features that have been linked to the exodus of modern humans from Africa 50,000 years ago.

Until now, one of the main reasons for doubting the "Out Of Africa" theory was the existence of inconsistent evidence in Australia. The skeletal and tool remains that have been found there are strikingly different from those elsewhere on the "coastal expressway" - the route through South Asia taken by the early settlers.

Some scholars argue that these discrepancies exist either because the early colonists interbred with the local Homo erectus population, or because there was a subsequent, secondary migration from Africa. Both explanations would undermine the theory of a single, common origin for modern-day humans.

But in the latest research there was no evidence of a genetic inheritance from Homo erectus, indicating that the settlers did not mix and that these people therefore share the same direct ancestry as the other Eurasian peoples.

Geneticist Dr Peter Forster, who led the research, said: "Although it has been speculated that the populations of Australia and New Guinea came from the same ancestors, the fossil record differs so significantly it has been difficult to prove. For the first time, this evidence gives us a genetic link showing that the Australian Aboriginal and New Guinean populations are descended directly from the same specific group of people who emerged from the African migration."

At the time of the migration, 50,000 years ago, Australia and New Guinea were joined by a land bridge and the region was also only separated from the main Eurasian land mass by narrow straits such as Wallace's Line in Indonesia. The land bridge was submerged about 8,000 years ago.

The new study also explains why the fossil and archaeological record in Australia is so different to that found elsewhere even though the genetic record shows no evidence of interbreeding with Homo erectus, and indicates a single Palaeolithic colonisation event.

The DNA patterns of the Australian and Melanesian populations show that the population evolved in relative isolation. The two groups also share certain genetic characteristics that are not found beyond Melanesia. This would suggest that there was very little gene flow into Australia after the original migration.

Dr Toomas Kivisild, from the Cambridge University Department of Biological Anthropology, who co-authored the report, said: "The evidence points to relative isolation after the initial arrival, which would mean any significant developments in skeletal form and tool use were not influenced by outside sources.

"There was probably a minor secondary gene flow into Australia while the land bridge from New Guinea was still open, but once it was submerged the population was apparently isolated for thousands of years. The differences in the archaeological record are probably the result of this, rather than any secondary migration or interbreeding."

The study is reported in the new issue of Proceedings of the National Academy of Sciences.

Notes for Editors:

1. Homo sapiens originated in Africa 150,000 years ago and began to migrate 55,000 to 60,000 years ago. It is thought he arrived in Australia around 45,000 years before present (BP). Australia was, at the time, already colonised by homo erectus. The eastern migration route towards Australia is referred to as the "coastal express" route, due to the comparatively rapid progress made by those who used it. This dispersal, from Africa to Australia through Arabia, Asia and the Malay peninsula, could have occurred at a rate of 1km per year.

2. Australia's archaeological record provides several apparent inconsistencies with the "Out Of Africa" theory. In particular, the earliest known Australian skeletons, from Lake Mungo, are relatively slender and gracile in form, whereas younger skeletal finds are much more robust. This robustness, which remains, for example, in the brow ridge structure of modern Aborigines, would suggest either interbreeding between homo sapiens and homo erectus or multiple migrations into Australia, followed by interbreeding. The archaeological data also indicates an intensification of the density and complexity of different stone tools in Australia during the Holocene period (beginning around 10,000 years BP), in particular the emergence of backed-blade stone technology. The first dingos arrived at around the same time, and it is thought both were brought to the continent by new human arrivals - leading to theories of a secondary migration that has resulted in disputes regarding the single point of origin theory.
Particularly like this bit...
the genetic record shows no evidence of interbreeding with Homo erectus,


No shit Sherlock! :lol:

They didn't find any Polar bears either!

Roy.
First people deny a thing, then they belittle it, then they say it was known all along! Von Humboldt

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Post by Minimalist » Fri May 15, 2009 2:49 pm

No shit Sherlock! Laughing


Permit me to offer you this graphic.

Image


You may need it.
Something is wrong here. War, disease, death, destruction, hunger, filth, poverty, torture, crime, corruption, and the Ice Capades. Something is definitely wrong. This is not good work. If this is the best God can do, I am not impressed.

-- George Carlin

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Post by Digit » Fri May 15, 2009 2:57 pm

I shall treasure it always Min! :lol:

Roy.
First people deny a thing, then they belittle it, then they say it was known all along! Von Humboldt

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Post by dannan14 » Fri May 15, 2009 3:45 pm

So does that mean that DNA has been recovered from HE? i think we've talked about that on a few threads, but i don't remember anyone finding any reports of HE DNA. Is my memory just acting like Swiss cheese again?

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