A Swim In Our Pool

Though India has had no role in the Human Genome Project (HGP), scientists here are associated with an allied programme that will further enrich the HGP's "rough draft".

The task of the Indian scientists involved in the international Human Genome Diversity Project is to document the genomic diversity in Indian populations. The project is being carried out by the Calcutta Consortium on Human Genetics, comprising the anthropology and human genetics unit of the Indian Statistical Institute (ISI), the Indian Institute of Chemical Biology and the Saha Institute of Nuclear Physics, all based in Calcutta. The goal is to reconstruct the evolutionary lineages of various ethnic groups of India.

ISI's Partha Majumder, project leader, has a whole lot of findings to enumerate. The first is, of course, about the earliest human presence in the subcontinent. If he is to be believed, modern humans arrived in India from Africa around 60,000 to 80,000 years ago. A subsequent demographic expansion resulted in dispersal of humans to other geographical regions, particularly to Southeast Asia and, possibly, also Oceania.

The research has also established that Indian populations were founded by a small group of females and a much larger group of males. It also indicates that cross-cultural assimilation of women into various population groups in India has been more frequent than that of men.

Finally, the study has also located mutant genes responsible for diseases like sickle cell anaemia in specific population groups. For instance, the errant gene for sickle cell has been found in various south Indian tribal groups. Interestingly enough, this mutant gene also makes them immune to malaria. Thus, members of these population groups, who are merely carriers-they carry the errant gene but do not suffer from sickle cell anaemia-have the best of both worlds. They don't have the anaemia and they are immune to malaria.