Africans Have Greatest Genetic Variation

(AP)  Africans have more genetic variation than anyone else on Earth, according to a new study that helps narrow the location where humans first evolved, probably near the South Africa-Namibia border.

The largest study of African genetics ever undertaken also found that nearly three-fourths of African-Americans can trace their ancestry to West Africa. The new analysis published Thursday in the online edition of the journal Science.

"Given the fact that modern humans arose in Africa, they have had time to accumulate dramatic changes" in their genes, explained lead researcher Sarah Tishkoff, a geneticist at the University of Pennsylvania.

People have been adapting to very diverse environmental niches in Africa, she explained in a briefing.

Over 10 years, Tishkoff and an international team of researchers trekked across Africa collecting samples to compare the genes of various peoples. Often working in primitive conditions, the researchers sometimes had to resort to using a car battery to power their equipment, Tishkoff explained.

The reason for their work? Very little was known about the genetic variation in Africans, knowledge that is vital to understanding why diseases have a greater impact in some groups than others and in designing ways to counter those illnesses.

Scott M. Williams of Vanderbilt University noted that constructing patterns of disease variations can help determine which genes predispose a group to a particular illness.

This study "provides a critical piece in the puzzle," he said. For example, there are clear differences in prevalence of diseases such as hypertension and prostate cancer across populations, Williams said.

"The human genome describes the complexity of our species," added Muntaser Ibrahim of the department of molecular biology at the University of Khartoum, Sudan. "Now we have spectacular insight into the history of the African population ... the oldest history of mankind.

"Everybody's history is part of African history because everybody came out of Africa," Ibrahim said.

Christopher Ehret of the department of history at the University of California, Los Angeles, compared genetic variation among people to variations in language.

There are an estimated 2,000 distinct language groups in Africa broken into a few broad categories, often but not always following gene flow.

Movement of a language usually involves arrival of new people, Ehret noted, bringing along their genes. But sometimes language is brought by a small "but advantaged" group which can impose their language without significant gene flow.

Overall, the researchers were able to study and compare the genetics of 121 African groups, 60 non-African populations and four African-American groups.

The so-called "Cape-colored" population of South Africa has highest levels of mixed ancestry on the globe, a blend of African, European, East Asian and South Indian, Tishkoff said.

"This will be a great population for study of diseases" that are more common in one group than another, she said.

The study also found that about 71 percent of African-Americans can trace their ancestry to western African origins. They also have between 13 percent and 15 percent European ancestry and a smaller amount of other African origins. There was "very little" evidence for American Indian genes among African-Americans, Tishkoff said.

Ehret added that only about 20 percent of the Africans brought to North America made the trip directly, while most of the rest went first to the West Indies.

And, he added, some local African-American populations, such as the residents of the sea islands off Georgia and South Carolina, can trace their origins to specific regions such as Sierra Leone and Guinea.

The study was funded by the National Cancer Institute, the National Institutes of Health, the Advanced Computing Center for Research and Education at Vanderbilt University, the L.S.B. Leakey and Wenner Gren Foundation, the National Science Foundation, the David and Lucile Packard and Burroughs Wellcome foundations.

[Hominatrix53]

and for the trillionith time, evolution has nothing to do with the origin of life.

[Hominatrix53]

This shouldn't come as a surprise to anyone who understands evolution. If 1000 people migrated out of Africa into Europe and Asia - the genetic material of the descendents of those 1000 people is limited to that very small population. The descendents of the 5 million who stayed in Africa arose from a more diverse genetic pool. It's simple math, folks.

[nic1234567-2009]

Wow...and you people actually believe in this nonsense. Amazing. You see how you're just sphewing philosophical assumptions (theories) and not eye-witnessed proven facts?
Posted by Culture_Warrior_in_09


No I don?t, I never said I belive it. I was only providing you with one of many theories. I was trying to answer your question ?How can LIVING come from NON-LIVING?? Since Scientists have created model Protocells in the lab and are on the verge of creating full function Protocell that should have satisfied your question. However your argument lacks any logic. Theories are not philosophical assumptions they require a body of fact which can be supported through observations and testing. Since Scientists have produce model Protocells in the lab this provides supporting evidence that Protocells may have existed in the past and could have been the building blocks for modern day cells.

Right now we don?t know if this theory is the correct one. Sometimes theories are falsified, meaning that an explicit set of observations contradicts some fundamental assumption of the theory, but more often theories are revised to conform to new observations.

By the way just to set your mind at easy I?m Christian but I believe that god is the guiding hand behind evolution.

[paddyhayes]

"overwhelming evidence points to the fact that all the complexities on the planet are mathematically impossible to have happened by chance"

You have to love it!

The "overwhelming evidence/Math" argument is fallacious from the start because it assumes that the "chances" can be quantified. Throw a few arbitrary numbers into an arbitrary equation and you can come up with a very big, impressive number.

But the basic underlying argument goes like this:

The universe is very complex. This could not have happened by chance. Therefore, an intelligent designer must exist.

See if you can identify the logical fallacies.

I can see at least Hasty Generalization, Non Sequitur, Assuming the Consequent.

Anyone see anything else?

[paddyhayes]

Speaking of "eye-witnessed proven facts", I have to go read Genesis again ...

<snicker>

[Culture_Warrior_in_09]

These organisms were able to survive and reproduce in a very limited environment because of their simplicity. Over time, some of these protocells came together and shared their specialization in a symbiotic relationship. These colonies of protocells eventually became the cells we know today. .
posted by nic1234567-2009

Wow...and you people actually believe in this nonsense. Amazing. You see how you're just sphewing philosophical assumptions (theories) and not eye-witnessed proven facts?

[Culture_Warrior_in_09]

nic1234567-2009

How does INTELLIGENCE come from NON-INTELLIGENCE?

[nic1234567-2009]

How can LIVING come from NON-LIVING?
Posted by Culture_Warrior_in_09

The study of the origin of life is called Abiogenesis not be confused with evolution and there are various theories. For example Protocells, which bridge nonliving and living matter. One theory of the origins of cells states that the first life on earth consisted of several types of tiny protocells, cell-like organisms. These organisms were able to survive and reproduce in a very limited environment because of their simplicity. Over time, some of these protocells came together and shared their specialization in a symbiotic relationship. These colonies of protocells eventually became the cells we know today. .

Protocells are extremely pared down and simple version of a cell, the Protocell is nonetheless capable of growth, replication, and evolution. Scientists have now created model Protocells in the lab and demonstrated how they might have taken up the nutrients that propelled their growth. A full working version of a Protocell has not yet been created in laboratory but it is within reach.

Here?s some web site the on the subject.

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

http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=11630

http://intranet.siu.edu/~protocell/photos.htm

[Culture_Warrior_in_09]

Looks like Right_Wing_Extremist got banned from these forums simply for disagreeing with Darwin.

Freedom of speech = Non existent here at CBS (unless you are a liberal or someone who appeases liberalism)

[Culture_Warrior_in_09]

It is not true that it is scientifically or mathematically impossible for life to come from non-living material
posted by nic1234567-2009

-Ok Genius. Explain how life can come from non-life (which defies all common sense at the surface from the get go), but go ahead, give it your best shot.

How can LIVING come from NON-LIVING?