New York, April 23 (IANS): Only we, the Homo sapiens, who lived side by side with Neanderthals and Denisovans of Siberia survived and a study offers fresh insights into what gave the modern man the advantage over other extinct humans.

It is the epigenetic changes that may have shaped our own species, said the study.

While genetics deals with the DNA sequence itself and the heritable changes in the DNA (mutations), epigenetics deals with heritable traits that are not caused by mutations.

This epigenetic regulatory layer controls where, when and how genes are activated, and is believed to be behind many of the differences between human groups, said the study.

Indeed, many epigenetic changes distinguish the modern man from the Neanderthal and the Denisovan, showed the team of researchers.

For the study, the researchers reconstructed the epigenome of the Neanderthal and the Denisovan.

Then, by comparing this ancient epigenome with that of modern humans, they identified genes whose activity had changed only in our own species during our most recent evolution.

Among those genetic pattern changes, many are expressed in brain development, found the researchers.

They also observed important changes in the immune and cardiovascular systems, whereas the digestive system remained relatively unchanged.

The study appeared in the journal Science.