A new study by researchers at the Smithsonian's National Museum of Natural History reveals that ancient humans were not as primitive as previously thought to be.

Previously, archaeologists were of the belief that hominids like Australopithecus sediba (lived 4 million and 2 million years ago) were physically and culturally less progressive when compared to the early man. It was also thought that nearly 2.4 million years ago, species like the Homo Erectus adapted to the changes and evolved a bigger brain and longer limbs, as well as the capability to make tools in order to adapt to the African climate becoming cooler and drier.

However, the new study suggests that several characteristics linked to the Home genus started developing million years prior to this period, which implies that the early humans were able to carry out the afore-mentioned tasks with ease earlier and were less primitive than thought.

"The traits that typify our own species Homo sapiens weren't there right at the beginning of the evolution of the Homo genus; instead, humanness evolved in much more of a mosaic pattern," says Dr. Rick Potts, curator of anthropology and director of the Human Origins Program at the Smithsonian's National Museum of Natural History.

The team of researchers analyzed an extensive "body of fossil evidence" that was of relevance to the origination of Homo sapiens to gain a better understanding into how human beings evolved.

The researchers based their findings on the analysis of fossil and climate evidence and reveal that early humans started developing longer limbs nearly 3.9 million years ago. The first tool-making by the primitive man dates back 2.6 million years, which is thousands of years prior to the recording of the first Homo genus.

The study also discovered that several Australopithecines were already in the process of adapting to environmental changes as they had a varied diet, something which is associated with early man.

The new data discovered by researchers also hints that the period from 2.5 million to 1.5 million years ago was an era of major climatic uncertainty. Intense shifts in wet and dry season every year also took place. Per the study, certain species like the Homo Erectus were more equipped at adapting to the environmental alteration and changed their diets in keeping with these climatic fluxes.

"Taken together, these data suggest that species of early Homo were more flexible in their dietary choices than other species. Their flexible diet-probably containing meat-was aided by stone tool-assisted foraging that allowed our ancestors to exploit a range of resources," explains Leslie Aiello, resident of the Wenner-Gren Foundation for Anthropological Research in the U.S.

The researchers, however, believe that the expansion of the brain did not start till 800,000 years ago. Moreover, homes and shelters did not come into being prior to this.

The study has been published in the journal Science.