Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Earth Science News .




ABOUT US
Mysterious ancient human crossed Wallace's Line
by Staff Writers
Adelaide, Australia (SPX) Oct 22, 2013


File image: Denisova cave in the Altai Mountains.

Scientists have proposed that the most recently discovered ancient human relatives -- the Denisovans -- somehow managed to cross one of the world's most prominent marine barriers in Indonesia, and later interbred with modern humans moving through the area on the way to Australia and New Guinea.

Three years ago the genetic analysis of a little finger bone from Denisova cave in the Altai Mountains in northern Asia led to a complete genome sequence of a new line of the human family tree -- the Denisovans. Since then, genetic evidence pointing to their hybridisation with modern human populations has been detected, but only in Indigenous populations in Australia, New Guinea and surrounding areas.

In contrast, Denisovan DNA appears to be absent or at very low levels in current populations on mainland Asia, even though this is where the fossil was found.

Published in a Science opinion article, scientists Professor Alan Cooper of the University of Adelaide in Australia and Professor Chris Stringer of the Natural History Museum in the UK say that this pattern can be explained if the Denisovans had succeeded in crossing the famous Wallace's Line, one of the world's biggest biogeographic barriers which is formed by a powerful marine current along the east coast of Borneo.

Wallace's Line marks the division between European and Asian mammals to the west from marsupial-dominated Australasia to the east.

"In mainland Asia, neither ancient human specimens, nor geographically isolated modern Indigenous populations have Denisovan DNA of any note, indicating that there has never been a genetic signal of Denisovan interbreeding in the area," says Professor Cooper, Director of the University of Adelaide's Australian Centre for Ancient DNA.

"The only place where such a genetic signal exists appears to be in areas east of Wallace's Line and that is where we think interbreeding took place -- even though it means that the Denisovans must have somehow made that marine crossing."

"The recent discovery of another enigmatic ancient human species Homo floresiensis, the so-called Hobbits, in Flores, Indonesia, confirms that the diversity of archaic human relatives in this area was much higher than we'd thought," says Professor Stringer, Research Leader in Human Origins, Natural History Museum, in London.

"The morphology of the Hobbits shows they are different from the Denisovans, meaning we now have at least two, and potentially more, unexpected groups in the area.

"The conclusions we've drawn are very important for our knowledge of early human evolution and culture. Knowing that the Denisovans spread beyond this significant sea barrier opens up all sorts of questions about the behaviours and capabilities of this group, and how far they could have spread."

"The key questions now are where and when the ancestors of current humans, who were on their way to colonise New Guinea and Australia around 50,000 years ago, met and interacted with the Denisovans," says Professor Cooper.

"Intriguingly, the genetic data suggest that male Denisovans interbred with modern human females, indicating the potential nature of the interactions as small numbers of modern humans first crossed Wallace's Line and entered Denisovan territory."

.


Related Links
University of Adelaide
All About Human Beings and How We Got To Be Here






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





ABOUT US
Sinking teeth into the evolutionary origin of our skeleton
Bristol, UK (SPX) Oct 22, 2013
For decades, it was thought that our skeleton and all its characteristic bony tissues originated in the predators, known as 'conodonts'. However new research, led by the University of Bristol and published in Nature, shows that they were evolutionary copy-cats who evolved tooth-like structures and tissues independently of other vertebrates. The origin of our skeleton is to be found in the ... read more


ABOUT US
Search to save smallest survivors of Australia fires

Indian farmer gets one-dollar cheque in flood relief

Quake-triggered landslides pose significant hazard for Seattle

Philippine quake island officials accused of aid 'hoarding'

ABOUT US
NASA Laser Communication System Sets Record with Data Transmissions to and from Moon

NSF Awards $12 Million to SDSC to Deploy "Comet" Supercomputer

Rice scientists create a super antioxidant

Cracked metal, heal thyself

ABOUT US
Malaysian tribes protest mega-dam

Palestinians, Israeli discuss water in latest peace talks

Africa faces water crisis despite discovery of huge aquifers

Study puts freshwater biodiversity on the map for planners and policymakers

ABOUT US
New study finds unprecedented warmth in Arctic

Greenpeace urges Russia to free activists after piracy charge lifted

Russia to boycott court hearings over Greenpeace ship

Nations debate giant Antarctic ocean sanctuaries

ABOUT US
Targeting cancer's sweet tooth

Targeted culling of deer controls disease with little effect on hunting

New soil testing kit for third world countries

Turfgrass tested in shallow green roof substrates

ABOUT US
The Complicated Birth of a Volcano

Hurricane Raymond weakens off Mexico coast

Dozens flee Japan mudslide island to beat new typhoon

Over 156,000 hit in South Sudan 'disaster' floods: UN

ABOUT US
Political killings drive Libya toward new civil war

Mozambique leader calls for talks to end violence

Kenya police cancel summons of journalists over Westgate

Forces in 'large-scale' operation against Mali extremists: Paris

ABOUT US
Mysterious ancient human crossed Wallace's Line

The evolutionary benefit of human personality traits

Hitchhiking virus confirms saga of ancient human migration

Marmoset monkeys know polite conversation




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement