Atlantis Online
October 25, 2014, 07:39:52 am
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Scientists to drill beneath oceans
http://atlantisonline.smfforfree2.com/index.php/topic,8063.0.html
 
   Home   Help Arcade Gallery Links Staff List Calendar Login Register  
Pages: [1] 2 3 4 5 6 7 ... 10
 1 
 on: October 23, 2014, 11:53:36 pm 
Started by Morrison - Last post by Morrison

Archaeologists document highest altitude ice age human occupation in Peruvian Andes
10 hours ago



Archaeologists document highest altitude ice age human occupation in Peruvian Andes
Sonia Zarrillo (U. of Calgary) at Cuncaicha. Credit: Kurt Rademaker

In the southern Peruvian Andes, an archaeological team led by researchers at the University of Maine has documented the highest altitude ice age human occupation anywhere in the world—nearly 4,500 meters above sea level (masl).

Their discoveries date high-altitude human habitation nearly a millennium earlier than previously documented.

Despite cold temperatures, high solar radiation and low oxygen conditions at that altitude, hunter-gatherers colonized the remote, treeless landscapes about 12,000 years ago during the terminal Pleistocene—within 2,000 years after humans arrived in South America.

"Study of human adaptation to extreme environments is important in understanding our cultural and genetic capacity for survival," according to the research team, led by Kurt Rademaker, a University of Maine visiting assistant professor in anthropology, writing in the journal Science.

The Pucuncho archaeological site, 4,355 masl, included 260 formal tools, such as projectile points, nondiagnostic bifaces and unifacial scrapers up to 12,800 years old. Cuncaicha rockshelter, featuring two alcoves at 4,480 masl, contains a "robust, well-preserved and well-dated occupation sequence" up to 12,400 years old. The rockshelter, with views of wetland and grassland habitats, features sooted ceilings and rock art, and was likely a base camp.

Most of the lithic tools at Cuncaicha were made from locally available obsidian, andesite and jasper, and are indicative of hunting and butchering consistent with limited subsistence options on the plateau, according to the researchers. In addition to plant remains, bones at the site indicate hunting of vicuña and guanaco camelids and the taruca deer.

Pucuncho Basin was a high-altitude oasis for specialized hunting, particularly of vicuña, and later, herding of domesticated alpacas and llamas. While the Pucuncho Basin could have sustained year-round residence, wet-season storms and the dangers of hypothermia, as well as the need to maintain extended social networks and collection of edible plants, may have encouraged regular descents, according to the research team.

In addition, the lithic tools and debitage included nonlocal, fine-grained rocks—some stream-polished. That would have required the plateau residents to visit high-energy rivers in the lower elevations.

It is unclear whether the high-altitude human settlement required genetic or environmental adaptations. But with evidence of high-altitude human habitation almost 900 years earlier than previously documented, the implication is that there may have been more moderate late-glacial Andean environments and greater physiological capabilities for Pleistocene humans.

"The Pucuncho Basin sites suggest that Pleistocene humans lived successfully at extreme high altitude, initiating organismal selection, developmental functional adaptations and lasting biogeographic expansion in the Andes," write the researchers. "As new studies identify potential genetic signatures of high-altitude adaptation in modern Andean populations, comparative genomic, physiologic and archaeological research will be needed to understand when and how these adaptations evolved."

Explore further: The genetic origins of high-altitude adaptations in Tibetans

More information: Paleoindian settlement of the high-altitude Peruvian Andes, by K. Rademaker et al. Science, www.sciencemag.org/lookup/doi/… 1126/science.1258260

http://phys.org/news/2014-10-archaeologists-document-highest-altitude-ice.html#nRlv

 2 
 on: October 23, 2014, 10:30:55 pm 
Started by Triton - Last post by Triton

Ten years on, scientists still debating the origins of Homo floresiensis—the 'Hobbit'
14 hours ago by Bob Yirka report




Homo floresiensis
Homo floresiensis adult female - model of head. Credit: John Gurche, National Museum of Natural History, CC BY-SA

(Phys.org) —It's been ten years since the bones of Homo floresiensis, aka, the "hobbit" were uncovered in Liang Bua, a cave, on the island of Flores in Indonesia, and scientists still can't agree on the diminutive hominin's origins. This month, the journal Nature has printed a comment piece by Chris Stringer of the Natural History Museum in London and two pieces by Ewen Callaway, one a retrospective with interviews with the central players, and the other a podcast with the four principle scientists involved in the find—Bert Roberts, Thomas Sutikna, Dean Falk, and Stringer.

Did H. floresiensis descend from Australopithecus, leaving Africa and somehow settling on Flores, or was it a case of an early member of our family tree finding its way to the island and then because of limited resources, evolving into a much smaller size? That's the central question in the debate.

The majority opinion has sided with the island effect, mostly because of the time frame— H. floresiensis existed a mere 13,000 years ago, which means it was alive when other Homo sapiens were about, thus it seemed to make sense that H. floresiensis was also a member that had become stranded on an island. But Stringer doesn't agree. In his commentary piece he notes the chin and jaw are more reminiscent of pre-human fossils, dating back approximately two million years. Also the body shape and tiny brain appear to be more primitive than humans. He says taken together, the evidence suggests a closer match with Australopithecus, a pre-human group living in Africa which also includes the remains of the famous "Lucy"—and which also date back to approximately 1.2 million years ago. But that would mean that some members of that ancient tribe would have had to travel a long way over the ocean to reach Flores. Stringer notes that another event that occurred ten years ago, offers evidence of just how that could have happened—the Indian Ocean tsunami that carried people atop debris for more than 150 kilometers. If that were the case, he wonders if other evidence of H. floresiensis might exist on other nearby islands.

Much more research still needs to be done to settle the debate—if other fossils are found that contain DNA evidence, for instance, that would surely help.


http://phys.org/news/2014-10-ten-years-scientists-debating-homo.html

 3 
 on: October 22, 2014, 12:10:49 am 
Started by Shadow Warrior - Last post by Shadow Warrior

 4 
 on: October 22, 2014, 12:10:34 am 
Started by Shadow Warrior - Last post by Shadow Warrior

 5 
 on: October 22, 2014, 12:10:23 am 
Started by Shadow Warrior - Last post by Shadow Warrior

 6 
 on: October 22, 2014, 12:09:38 am 
Started by Shadow Warrior - Last post by Shadow Warrior

 7 
 on: October 22, 2014, 12:09:20 am 
Started by Shadow Warrior - Last post by Shadow Warrior

 8 
 on: October 22, 2014, 12:08:58 am 
Started by Shadow Warrior - Last post by Shadow Warrior

 9 
 on: October 22, 2014, 12:08:43 am 
Started by Shadow Warrior - Last post by Shadow Warrior

 10 
 on: October 22, 2014, 12:08:27 am 
Started by Shadow Warrior - Last post by Shadow Warrior

Pages: [1] 2 3 4 5 6 7 ... 10
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 © 2013, Simple Machines