Tuesday, September 15, 2009

Le evolution human ha accelerate rapidemente in le ultime 5.000 annos.

(Languages of this post: Interlingua, English)

Usque nunc, le majoritate del scientistas qui studia le evolution human ha credite que illo ha cambiate a un taxa multo lente, Ma nove studios indica que le evolution human ha movite a un taxa rapidissime in le mille annos passate.

Nove evidentia indica que le differentia genetic inter humanos contemporanee e humanos qui viveva ante 5.000 annos es plus grande que le differentia inter iste ancestres nostre e le neanderthales qui deveniva extincte ante 30.000 annos, secundo John Hwsks del Universitate de Wisconsin.

Multe cambios genetic reflecte differentias in le dieta human post le disveloppamento del agricultura, tanto como resistantia a maladias epidemic que exterminava grande numeros de personas post le crescimento del civilisation human.

Pro exemplo, africanos ha nove genes que provide resistentia a malaria. In europeos, il ha un gen que facilita lor capacitates de digerer lacte in lor annos adulte. In orientales il ha un gen que augmenta le siccitate del cera in lor aures.

Un importante causa de iste cambios es le crescimento colossal del population human, desde unes pauc milliones usque 6,5 billiones in le ultime 10.000 annos, con grande gruppos de personas qui migrava a nove ambientes al quales illes debeva adaptar se, diceva Henry Harpending, un anthropologo al Universitate de Utah.

“Le discoperimento principal de iste nove studios es que le evolution human accelera a un taxa rapidissime, plus rapidemente que nos pensava”, dice Harpending. “Le major parte del acceleration ha essite in le ultime 10.000 annos, un brevissime momento in le curso de evolution biologic.”

Le recercatores qui travalia in iste projecto ha discoperite mutationes genetic favorabile que appareva in le ultime 80.000 annos per le analyse de quantitates massive de information de 270 personas de differente populations trans le mundo.

Datos de iste projecto HapMap, que significa le mappamento de haplotypos, ha compilate lo que es essentialmente un catalogo de differentias e similaritates genetic in personas qui nunc vive.

Examinante tal datos, on pote verificar exactemente quando un certe cambio genetic appareva in le genoma human e le taxa de rapiditate de cambios genetic in le passato distante.

Recercatores qui studia le evolution microbiologic del racia human ha discoperite que cambios genetic benefic ha apparite a un taxa plus o minus 100 vices plus rapidemente in le ultime 5.000 annos que a ulle altere epocha del evolution human, e illes dice que circa 7 procento del genes human ha cambiate rapidemente in annos assatis recente. Mesmo con iste cambios, le DNA human es plus que 99 procento identic inter le populationes human contemporanee.

Harpending diceva que le evidentia genetic monstra que le populationes in le diverse partes del mundo ha devenite minus simile a causa de cambios genetic assatis recente.

Le genoma human ha evolvite assatis rapidemente in Africa, Asia, e Europa, ma quasi omne su cambios ha essite unic intra le personas qui vive in iste regiones. Le causa de isto es que post le migration de humanos desde Africa a altere partes del mundo ante circa 40.000 annos il non ha habite multe fluxo de genes inter iste regiones.


Up to now, the majority of scientists who study human evolution have believed that it has been changing at a very slow rate. But new studies indicate that human evolution has been moving at a very rapid rate in the past thousand years.

New evidence indicates that the genetic difference between contemporary humans and the humans who lived 5,000 years ago is greater than the difference between these ancestors of ours and the Neanderthals who became extinct 30,000 years ago, according to John Hawks of the University of Wisconsin.

Many genetic changes reflect differences in the human diet after the development of agriculture, as well as resistance to epidemic illnesses that exterminated large numbers of people after the development of human civilization.

For example, Africans have new genes that provide resistance to malaria. In Europeans, there is a gene that makes it easier for them to digest milk in their adult years. In Asians, there is a gene that increases the dryness of wax in their ears.

An important cause of these changes is the colossal growth of the human population, from a few millions up to 6.5 billions in the past 10,000 years, with large groups of people who migrated to new environments to which they had to adapt themselves, said Henry Harpending, an anthropologist at the University of Utah.

“The principal discovery of these new studies is that human evolution is accelerating very fast, more rapidly than what we thought,” says Harpending. “Most of the acceleration has been in the last 10,000 years, a very brief moment in the course of biological evolution.”

The investigators who are working on this project have discovered favorable genetic mutations that appeared in the last 80,000 years by analyzing massive amounts of information from 270 people of different populations throughout the world.

Data from this HapMap project, (HapMap means haplotype mapping), have compiled what is essentially a catalogue of genetic differences and similarities in people who are now living.

By examining such data, it is possible to verify exactly when a certain genetic change appeared in the human genome and the rate of speed of genetic changes in the distant past.

Researchers studying the microbiological evolution of the human race have discovered that beneficial genetic changes have appeared more or less 100 times more rapidly in the last 5,000 years than at any other period in human evolution, and they say that around seven percent of of human genes have changed in rather recent years. Even with these changes, human DNA is more than ninety-nine percent identical among contemporary human populations.

Harpending said that the genetic evidence shows that the populations in the various parts of the world have become less similar because of rather recent genetic changes.

The human genome has evolved rather rapidly in Africa, Asia, and Europe, but almost all its changes have been unique among the people who live in these regions. The cause of this is that after the migration of people from Africa to other parts of the world around 40,000 years ago there has not been a great flow of genes between these regions.

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