The mystery about gaps

If you have a gaps in your teeth, just blame it on your genes. Researchers from the University of Texas and Baylor College of Medicine, USA, have found that missing teeth are linked with a mutation in the gene called PAX9. It is one of the genes that help to determine body shape and to form organs in the womb. Rene D'Souza, who is one of the researchers, feels that the mutation means that people do not make enough of the PAX9 protein to develop all their teeth.

Evolution of bats

A new study on the DNA (deoxyribonucleic acid) of bats has put a question mark on all the theories about the evolution of bats. It was believed that all bats shared a common ancestor, but subsequent generations evolved into two sub-orders according to whether they locate their prey by sight (the megabats) or sound (the microbats). Now, Michael Stanhope of the Queen's University of Belfast in the UK, who has done a detailed study on mammals' DNA, has come up with a new theory. According to Stanhope, one family of microbats is more closely related to the megabats than to other microbats. "It means either that echolocation evolved twice, or that it was lost by the megabats,' says Stanhope ( New Scientist , Vol 165, No 2221).

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