Today at Discovery News you can read about the earliest recognized species of Homo, the first known member of our genus. This latest addition to the human family, Homo gautengensis, was from South Africa and measured just 3 feet tall. It spent a lot of time in trees and had big teeth suitable for chewing plant material. H. gautengensis emerged over 2 million years ago, but died out at around 600,000 years ago.

(Homo gautengensis skull: Credit: Darren Curnoe)

The past few years have seen an explosion in the discovery of early human ancestors. Over just the past couple of months alone, we were presented with X-Woman and Australopithecus sediba. One reason for the explosion is improved analysis methods, often based on prior finds, DNA work, and a better understanding of where such remains might exist.

Get ready for more big human evolution announcements in the coming months, as anthropologists have shared with me that a number of bones even older than those for Homo gautengensis await study and classification. 

Colin Groves, a professor in the School of Archaeology & Anthropology at the Australian National University in Canberra informed me that the new finds are telling us "that there were a number of distinctive, perhaps short lived, species of proto-humans living in both eastern and southern Africa in the period between 2 and 1 million years ago."

He added, "Their presence reminds us that human evolution was not a single line: that, like most other large mammals, there was branching and diversification in the evolutionary tree."

"Some branches persisted, others died out."

(Neanderthal child reconstruction; Credit: Christoph P.E. Zollikofer)

Now the question that's on many minds is: what happened to all of these other humans, especially the ones that co-existed with our species? Did they die out due to some disaster, disease, or other natural cause? Or did we bump them off?

As University of New South Wales anthropologist Darren Curnoe, who identified Homo gautengensis, told me, it's very unusual in human history for there to be just the one species- Homo sapiens. 

Curnoe said, "If we compress all of human evolution into a single year, we have been alone since the last hour on December 31."

In the months to come, we'll learn more about all of those other past hours and millions of years, when many humans and proto-humans existed.