Our human-ancestors learning in 2011

Genetic hints of extinct human lineages - and the benefits we might have received from having sex with them - were among the discoveries this year regarding the evolution of our species, LiveScience reports.

Other key findings include evidence strengthening the case that fossils in South Africa might be those of the ancestor of the human lineage. Research also suggests humans crossed what is now the desolate Arabian Desert to expand out of Africa across the world. Although we modern humans are the only surviving members of our lineage, other kinds of humans once roamed the Earth, including familiar Neanderthals and the newfound Denisovans, who lived in what is now Siberia.

"Everywhere you look now, we find a little bit of interbreeding," said population geneticist Michael Hammer at the University of Arizona in Tucson. Hammer noted that he and his colleagues were very conservative with their analysis, only looking for lineages that diverged even more from modern humans than Neanderthals. "It's possible there may be others we can detect that are more closely related to modern humans," Hammer told LiveScience. "We've probably just scratched the surface of what we might find," he added. "We only looked at a small number of regions of the genome. This coming year, you'll see a lot of progress made with full genome data. This year, we should be able to confirm what we found and go way beyond that."

Read the full article on www.livescience.com.