Taming of the Shrew

Recent genetic research on rats shows the possibility of taming hitherto untamable species

The very existence and evolution of human civilisation owes much to the ability to tame animals. Agriculture without plough-pulling animals was far more difficult if not quite impossible. Nomads exist only because animals could be tamed for transportation and pasturage. This ability to tame animals has remained a mystery. Closely related species can respond very differently. The Asian elephant has been tamed for thousands of years, the African elephant has proved resistant to all such attempts. Asses have been used by humans for thousands of years, but the hardy wild asses of India, which inhabit extremes of climate such as the Rann of Kutch and heights of the Himalayas, have proved resistant.

Now scientists have tracked down the location of the genes responsible for tameness in the rat genome. “I hope our study will ultimately lead to a detailed understanding of the genetics and biology of tameness,” said Frank Albert, a scientist with the Max Planck Institute for Evolutionary Anthropology in Germany. The work, he and his colleagues feel, could extend to other species. Already, speculation has started that this could lead to ways of taming species that had been resistant to such efforts by introducing new genes into new generations.

The antecedents of the research published in the June issue of Genetics are fascinating in themselves. In 1972 Russian researchers in Novosibirsk caught a large group of wild rats which they then arbitrarily split into two groups. In one group, called the ‘tame’ rats, the scientists mated the friendliest rats (those that tolerated humans) with one another, and in the other group they mated the most aggressive rats with each other. These rats have been bred separately for several generations and now display very different behaviour. The tame ones actually tolerate human touch, while the aggressive rats raise a clamour and even bite.

Mark Johnston, editor-in-chief of Genetics, said, “This research offers clues about how genomes can be manipulated to breed tame animals of species once believed to be untamable.”

civilisationevolutiongeneticsrats