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Author Topic: Are Africans at a genetic advantage?  (Read 5910 times)

Offline Jessica H

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Are Africans at a genetic advantage?
« on: 24/02/2010 20:58:29 »
Since humans went through many bottlenecks as they migrated out of Africa, meaning that a few people are the ancestors of all Europeans, Asians, etc., I've heard there is more genetic diversity among native Africans.  As a result, are there less recessive genetic diseases in this population?  If some sort of new plague scavenges the Earth, isn't it then more likely that there might be individuals with immunity in the native African population than any other place?
« Last Edit: 12/03/2010 08:54:46 by chris »


 

Offline yor_on

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Re: Are Africans at a genetic advantage?
« Reply #1 on: 26/02/2010 00:08:23 »
That's a really interesting question Jessics, we all seem to contain the same genes more or less but. "Yes and no. While the human genome is mostly the same in all people, slight differences exist. This genetic variation, spread across many genes, makes up about one-tenth of a percent of each person's DNA. Yet these small differences are enough to create people with different appearances and different health. These differences are often inherited, so the more closely related two people are, the more similar their DNA is likely to be." Genetic variations but there is a probability of certain recombinations of genes due to those bottlenecks, possibly? Like they work together a little differently maybe?

"Simply speaking, variation is difference. Genetic variation is a difference in DNA. The “letters” of DNA are molecules called nucleotides: adenine, cytosine, guanine and thymine (A,C,G,T) strung together in long chains called sequences. The occasional single-letter differences that distinguish DNA among people are called single-nucleotide polymorphisms (SNPs, pronounced "snips")."

So in that motto we are all the same, Africans may have certain combinations we don't have as their environment differ from f.ex Sweden but we too may have certain variabilities they don't have. Island is a good example on a little population that have lived isolated for a long time and therefore may have narrower range of genetic variation, even though they too have all the same genes we others have :)
 

Offline JimBob

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Re: Are Africans at a genetic advantage?
« Reply #2 on: 26/02/2010 03:04:00 »
Actually, the genetic make up of Africans is quite a bit  more diverse than any other place on earth.

A massive new study of human genetic diversity reveals surprising insights into our species' evolution and migrations—including support for the theory that the first modern humans originated in Africa—scientists said today.

Researchers compared 650,000 genetic markers in nearly a thousand individuals from 51 populations around the globe—an unprecedented level of detail for a human genetic study.

You get less and less variation the further you go from Africa," said Marcus Feldman, an evolutionary biologist at Stanford University in California and a study co-author.

Such a pattern fits the theory that the first modern humans settled the world in stepping-stone fashion after leaving Africa less than 100,000 years ago.

As each small group of people broke away to found a new region, it took only a sample of the parent population's genetic diversity.

"If you keep sampling like that, then mathematically you must lose variation," Feldman explained.


More info is found at http://news.nationalgeographic.com/news/2008/02/080221-human-genetics.html

What this means, in my humble opinion, is that YES, the chance of a population surviving in Africa IF genetics is a factor in the disease is much more likely than in the rest of the world.
 

Offline yor_on

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Re: Are Africans at a genetic advantage?
« Reply #3 on: 27/02/2010 08:56:58 »
But couldn't it be turned around too?

Like those that did migrate have gotten a 'finer level' of specialization due to the new environments they meet, and therefore might have a better defense mechanism  when treating new diseases?
 

Offline echochartruse

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Are Africans at a genetic advantage?
« Reply #4 on: 26/03/2010 00:23:03 »
Since humans went through many bottlenecks as they migrated out of Africa, meaning that a few people are the ancestors of all Europeans, Asians, etc., I've heard there is more genetic diversity among native Africans.  As a result, are there less recessive genetic diseases in this population?  If some sort of new plague scavenges the Earth, isn't it then more likely that there might be individuals with immunity in the native African population than any other place?

I have seen a documentary stating that a few African woman have become immune to AIDS is this true
 

Offline echochartruse

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Are Africans at a genetic advantage?
« Reply #5 on: 26/03/2010 00:30:12 »
As each small group of people broke away to found a new region, it took only a sample of the parent population's genetic diversity.


Are you saying that the African population continued to diversify after some left?
 

Offline Jessica H

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Are Africans at a genetic advantage?
« Reply #6 on: 26/03/2010 03:29:01 »

Yes, I've heard some African sex workers are immune to HIV.  Since HIV is so common in parts of Africa, I think it has more to do with that than anything.

Here's an article about it:

http://www.guardian.co.uk/world/2007/may/27/aids.features
 

Offline echochartruse

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Are Africans at a genetic advantage?
« Reply #7 on: 30/03/2010 18:58:13 »
I have since found that crops are more divsers in places they are first cultivated.
 

Offline stereologist

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Are Africans at a genetic advantage?
« Reply #8 on: 04/04/2010 05:28:38 »
The genes may appear to  be slightly different, but the physical people are really quite different. Consider our kidneys. These organs are small, about the size of a computer mouse. Yet 20% of the blood is sent to the kidneys. Inside of the kidneys are structures called glomerulae. This is where the blood is 'cleansed'. The more of these we have the better off we are. Some people have as few as 150K some people have 1.2M. That's a 9x difference across humans. This is believed to be the reason that some groups of people are more susceptible to renal problems. Those with fewer glomerulae to start with are more likely to end up in trouble in later years.

I will look up some of the work done by John Bertram in Melbourne to see if I can find out which groups of people have more of these structures.
 

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Are Africans at a genetic advantage?
« Reply #8 on: 04/04/2010 05:28:38 »

 

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