New Delhi, May 15 -- An analysis of ancient teeth is giving scientists a rare peek into interactions between human relatives hundreds of thousands of years ago that have left a lasting imprint on our species.

A new study reveals genetic clues about a human ancestor called Homo erectus. H. erectus arose in Africa about 2 million years ago and spread to other parts of the globe, including Asia and possibly Europe.

Scientists have found remains from this early human in countries including Indonesia, Spain, China and Georgia. But genes and proteins don't preserve well so information about the early humans' internal makeup has proved elusive.

In a new work, researchers siphoned ancient enamel proteins from H. erectus teeth belonging to five...