Neanderthal DNA illuminates split with humans [Brány vnímání]

Věda / Archeologie

Neanderthal DNA illuminates split with humans

New Scientist, Středa 11. října 2006

@gorgrog

The first comparison of human and Neanderthal DNA shows that the two lineages diverged about 400,000 years ago and that Neanderthals may have had more DNA in common with chimps than with modern humans.

There is ongoing debate over whether the Neanderthals were a separate species, Homo neanderthalensis, or a subspecies of Homo sapiens. The first Neanderthals are thought to have emerged about 350,000 years ago, so the new findings from this DNA analysis strongly favour the theory that modern humans and Neanderthals share a common ancestor but are not more closely related than that.

Genetic analysis of Neanderthals is very tricky because mere fragments of nuclear DNA have been recoverable from fossils. Previous analyses have focused on mitochondrial DNA samples, which survive better.

James Noonan at Lawrence Berkeley National Laboratory in California, US, and colleagues compared human, chimpanzee and Neanderthal nuclear DNA samples. The newly compiled DNA dataset was derived from the remains of a 45,000-year-old Neanderthal fossil.

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From the enriched dataset, the researchers calculated that humans and Neanderthals diverged approximately 400,000 years ago. And the new data promise to reveal more about the genetic basis of differences between humans and Neanderthals – differences that presumably resulted in the success of modern humans as a species – the researchers say.

“This is a hint of exciting things to come as more Neanderthal sequence is produced,” says David Haussler at the University of California, Santa Cruz, US.

The researchers say the findings strengthen the argument that Neanderthals did not contribute substantially to the modern human genome. “Were there Neanderthals in our lineage? All of the genetics seems to be going in the direction that there weren’t,” says Richard Potts, head of the Smithsonian Institution's Human Origins Program in Washington DC, US.

Noonan will present the findings at the American Society of Human Genetics conference in New Orleans, US, this week

Převzato z New Scientist

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SVĚDKOVÉ VÁLKY

Svědectvím zřejmě nejstarší známé války na světě jsou hliněné kulky objevené při vykopávkách v syrském Hamoukaru. Tým syrských a amerických archeologů tam našel asi 1200 hliněných kulek, které pocházejí zhruba z doby 3500 let př. n. l. Kromě kulek se našla i keramika různých typů, což svědčí o tom, že obyvatelé z mezopotamského města Uruk obsadili krátce po bitvě Hamoukar. Archeologové předpokládají, že armáda několika set vojáků z Uruku napadla Hamoukar, ale zjistila, že je dobře opevněn. Mnoho kulek je zploštělých, evidentně neměly čas ztvrdnout před použitím. Vědci to pokládají za důkaz, že vojákům z Uruku došla munice, a proto si kulky na místě rychle vyráběli z jílu. Zřejmě šlo o snahu Uruku zlikvidovat politického a ekonomického soupeře, kterým byl Hamoukar.

http://stoplusjedna.newtonit.cz/

Pátek 15. prosince 2006

Homo Genus Skull Found In 360 Million Year Old Quarry This may be another piece in the cosmic jigsaw puzzle of our true human origins. Primate Skull, genus Homo found in marble quarry: 360 million years old

From Brad Steiger [All four photographs are copyright by Professor Mohammed Zarouit] 12-2-5

In July 2005, a small primate skull was discovered in the desert of Tafilalet near Erfound, Morocco. It was in the sand of a marble quarry where Devonian fossils were already found. Subsequently, the skull could be around 360 million years old. Characteristic features in the only 6.1 cm high and 3.9 cm broad fossil indicate the genus Homo: a globular forehead and hind skull and an inferior position of the occipital hole under the cranium, which is typical for upright body posture. The fossil was called Homo alaouite, in homage to the Alaouite Dynasty. '