Atlantis Online
July 15, 2019, 07:00:58 pm
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Plato's Atlantis: Fact, Fiction or Prophecy?
Article Source: http://EzineArticles.com/?expert=CarolAnn_Bailey-Lloyd
http://www.underwaterarchaeology.com/atlantis-2.htm
 
  Home Help Arcade Gallery Links Staff List Calendar Login Register  

Tooth gives up oldest human DNA

Pages: [1]   Go Down
  Print  
Author Topic: Tooth gives up oldest human DNA  (Read 29 times)
Crystal Thielkien
Superhero Member
******
Posts: 4531



« on: January 08, 2009, 01:25:53 pm »

Tooth gives up oldest human DNA  
By Helen Briggs
BBC News science reporter 



 
Neanderthals died out about 29,000 years ago
Scientists have recovered DNA from a Neanderthal that lived 100,000 years ago - the oldest human-type DNA so far.

It was extracted from the tooth of a Neanderthal child found in the Scladina cave in the Meuse Basin, Belgium.

The study, reported in Current Biology, suggests our distant cousins were more genetically diverse than once thought.

Their diversity had declined, perhaps because of climate change or disease, by the time modern humans arrived in Europe about 35,000 years ago.

Past diversity

French and Belgian researchers isolated the genetic material from mitochondria. These are "power pack" structures in cells which contain their own DNA.




  Diversity tells us about how old a population is and its demographic history

Dr Robert Foley
The scientists decoded the sequence of 123 DNA "letters" (base-pairs, or bp) and compared it with other known Neanderthal DNA sequences from specimens dated between 29,000 and 42,000 years old.

"The Scladina sequence has revealed that the genetic diversity of Neanderthals has been underestimated," a team led by Dr Catherine Hanni of Ecole Normale Superieur in Lyon, France, wrote in the journal Current Biology.

"Thus, more Neanderthal sequences than the six presently available and longer than 100 bp are needed to fully understand the extent of the past diversity of Neanderthals."

Disease threat

The findings suggest that genetic diversity was greater in earlier Neanderthal history than in later times, when modern humans started to arrive in Europe.

 
The DNA came from the molar of a 10-12 year-old child. (Image: G Focant)
Such changes are thought to reflect fluctuations in the population, caused by disease or environmental change, as well as random genetic mutations over time.

"Diversity tells us about how old a population is and its demographic history," said Dr Robert Foley, an expert in human evolution at the University of Cambridge, UK.

Neanderthals lived between 230,000 and 28,000 years ago in Europe, Central Asia and the Middle East.

They were skilled hunters and well adapted to living during the ice ages; but they started to die out after modern humans (Cro-Magnons) appeared on the scene in Europe.

The reason for their sudden demise is unknown, but various theories have been proposed, including biological, environmental and cultural factors.

The DNA studies conducted so far suggest little, if any, interbreeding between Neanderthals and moderns took place.


http://news.bbc.co.uk/2/hi/science/nature/5052414.stm
Report Spam   Logged



Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by EzPortal
Bookmark this site! | Upgrade This Forum
SMF For Free - Create your own Forum | Buy traffic for your forum/website
Powered by SMF | SMF © 2016, Simple Machines
Privacy Policy