A Setback for Racists: Among Many Peoples, Little Genomic Variety

[one...two...tree 2,762]

By David Brown Washington Post Staff Writer

There is a simplicity and all-inclusiveness to the number three -- the triangle, the Holy Trinity, three peas in a pod. So it's perhaps not surprising that the Family of Man is divided that way, too.

All of Earth's people, according to a new analysis of the genomes of 53 populations, fall into just three genetic groups. They are the products of the first and most important journey our species made -- the walk out of Africa about 70,000 years ago by a small fraction of ancestral ** sapiens.

One group is the African. It contains the descendants of the original humans who emerged in East Africa about 200,000 years ago. The second is the Eurasian, encompassing the natives of Europe, the Middle East and Southwest Asia (east to about Pakistan). The third is the East Asian, the inhabitants of Asia, Japan and Southeast Asia, and -- thanks to the Bering Land Bridge and island-hopping in the South Pacific -- of the Americas and Oceania as well.

The existence of this ancient divergence has long been known.

What is new is a subtle but important insight into what happened on a genomic level as the human species spilled across the landscape, eventually occupying every habitable part of the planet.

People adapted to what they encountered the way all living organisms do: through natural selection. A small fraction of the mutations constantly creeping into our genes happened by chance to prove beneficial in the new circumstances outside the African homeland. Those included differences in climate, altitude, latitude, food availability, parasites, infectious diseases and lots of other things.

A person who carried, by chance, a helpful mutation was more likely to survive and procreate than someone without it. The person's offspring would then probably be endowed with the same beneficial mutation. Over thousands of generations, the new variant (what geneticists call the "derived allele") could go from being rare to being common as its carriers fared better than their brethren and contributed more descendants to the population.

Scientists have long known that regardless of ancestral home or ethnic group, everyone's genes are pretty much alike. We're all ** sapiens. Everything else is pretty much details.

Recent research has produced a surprise, however. Population geneticists expected to find dramatic differences as they got a look at the full genomes -- about 25,000 genes -- of people of widely varying ethnic and geographic backgrounds. Specifically, they expected to find that many ethnic groups would have derived alleles that their members shared but that were uncommon or nonexistent in other groups. Each regional, ethnic group or latitude was thought to have a genomic "signature" -- the record of its recent evolution through natural selection.

But as analyses of genomes from dozens of distinct populations have rolled in -- French, Bantu, Palestinian, Yakut, Japanese -- that's not what scientists have found. Dramatic genome variation among populations turns out to be extremely rare.

Instead, it is "random genetic drift" that appears to be more important in sculpting our genes. Drift describes the chance loss of genetic variation that occurred not only in the out-of-Africa migration, but through all of human history as famine, climate change or war caused populations to crash and then recover.

Despite those calamities, it appears that all contemporary populations ended up largely the same, or only crudely distinguishable from one another, on the genome level.

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[Peikko 1,575]

Three peas in a pod? What poppycock!

Now that I have got past that, I'll read the rest, but with a jaundiced eye...

[Saddle Bronc 124]

A rather strange coincidence: the study found only three broad ethnic groups, guess how many broad ethnic groups the Bible identifies--THREE (descendants of Noah's three sons--Shem, Ham and Japheth)!

[AlHayatZween 2]

i love it when Cleo says "poppycock".

[mawilson 2,133]

All of Earth's people, according to a new analysis of the genomes of 53 populations, fall into just three genetic groups.

...

The existence of this ancient divergence has long been known.

Old text books called them Caucasoids, Negroids and Mongoloids - unpopular terms these days.

[Trumplestiltskin 5,791]

You can't "setback" racists with reason - they're ignorant and irrational.

[Peikko 1,575]

All good points

The reality is that from a genetic point of view, we are all the same. Our differences really are visual.

[one...two...tree 2,762]

All of Earth's people, according to a new analysis of the genomes of 53 populations, fall into just three genetic groups.

...

The existence of this ancient divergence has long been known.

Old text books called them Caucasoids, Negroids and Mongoloids - unpopular terms these days.

Because the more accurate terms are African, Eurasian and East Asian. Time to put those old textbooks in the trash and read something more up to date.

[Trumplestiltskin 5,791]

It goes back to the bible I think - the descendents of Shem, Japhet and Ham.

[mawilson 2,133]

The reality is that from a genetic point of view, we are all the same. Our differences really are visual.

Poppycock! The genetic differences are huge. You can identify a person's race from a blood sample.

Here's one example of a genetic difference I was able to google in 5 seconds.

[AlHayatZween 2]

Stop saying "poppycock"!

You are making me giggle in this dark, lifeless dungeon of a workplace.

[almaty 19]

The reality is that from a genetic point of view, we are all the same. Our differences really are visual.

Poppycock! The genetic differences are huge. You can identify a person's race from a blood sample.

Here's one example of a genetic difference I was able to google in 5 seconds.

there is a differnece based on enviromental variables over time...

[Peikko 1,575]

Poppycock indeed! There are variations within each of the so called 'races' that are genetically greater than between them. Stick that in your half baked pipe and smoke it!

[mawilson 2,133]

Poppycock indeed! There are variations within each of the so called 'races' that are genetically greater than between them. Stick that in your half baked pipe and smoke it!

That's true also, but there *are* genetic differences between races, as well as within each race.

[almaty 19]

Poppycock indeed! There are variations within each of the so called 'races' that are genetically greater than between them. Stick that in your half baked pipe and smoke it!

hey..now wait a second sister purple, first of all....my pipe is not half-baked...