(Charles Choi, LiveScience)
The controversial extinct human lineage known as “hobbits” gained a face this year, one of many projects that shed light in 2012 on the history of modern humans and their relatives. Other discoveries include the earliest known controlled use of fire and the possibility that Neanderthals or other extinct human lineages once sailed to the Mediterranean.
Here’s a look at what we learned about ourselves through our ancestors this year.
We’re not alone
A trove of discoveries this year revealed a host of other extinct relatives of modern humans. For instance, researchers unearthed 3.4-million-year-old fossils of a hitherto unknown species that lived about the same time and place as Australopithecus afarensis, a leading candidate for the ancestor of the human lineage. In addition, fossils between 1.78 million and 1.95 million years old discovered in 2007 and 2009 in northern Kenya suggest that at least two extinct human species lived alongside Homo erectus, a direct ancestor of our species. Moreover, fossils only between 11,500 and 14,500 years old hint that a previously unknown type of human called the “Red Deer Cave People” once lived in China.
Bones were not all that scientists revealed about modern humans’ extinct relatives in 2012. For instance, scientists finally put a face on the hobbit, a nickname for a controversial human lineage. Anthropologist Susan Hayes at the University of Wollongong in Australia reconstructed the appearance of the 3-foot (1-meter) tall, 30-year-old female member of the extinct humans officially known as Homo floresiensis, which were first discovered on the remote Indonesian island of Flores in 2003. [Image Gallery: A Real Life 'Hobbit']
DNA extracted from a recently discovered extinct human lineage known as the Denisovans — close relatives of Neanderthals — also revealed new details about this group, which once interbred with modern humans. The Denisovan genome that was sequenced belonged to a little girl with dark skin, brown hair and brown eyes, and displayed about 100,000 recent changes in our genome that occurred after the split from the Denisovans. A number of these changes influenced genes linked with brain function and nervous system development, leading to speculation that we may think differently from the Denisovans.
Genetic analysis also suggested the only modern humans whose ancestors did not interbreed with Neanderthals were apparently sub-Saharan Africans. These findings are just one tidbit regarding the closest extinct relatives of modern humans that was revealed this year. Scientists also found that the unusually powerful right arms of Neanderthals might not have been due to a spear-hunting life as was previously suggested, but rather one often spent scraping animal skins for clothes and shelters. Archaeologists also suggested that Neanderthals and other extinct human lineages might have been ancient mariners, venturing to the Mediterranean Islands millennia before researchers think modern humans arrived at the isles.
Humans’ tool use
Ancient artifacts revealed this year also have shown how tool use has helped humanity reshape the world — and perhaps inadvertently reshape humanity as well.