DNA fingerprinting of birds.

DNA fingerprinting of birds

Sorting out who begat whom in the animal world can be amessy affair. Using genetic techniques developed in the last two decades, scientists have been able to detect differences fairly well between species and between general populations of animals, but they have had far less success in making the finer distinctions of parentage within a given population or species.

Two papers appearing in the May 14 NATURE, however, showthat "DNA fingerprinting'--an extraordinarily sensitive genetic technique developed for humans and used in forensic identification of individuals as well as paternity and maternity questions--can home in on genetic relations among wild sparrows as well as it does for humans. And other papers in press suggest that the technique applies to cats, dogs and mice as well.

"Its use provides an excellent means for resolving relatednessin nature, and is likely to revolutionize the study of those aspects of behavior, population genetics and biometry that require a detailed demographic knowledge of populations,' write Jon H. Wetton and his co-workers at Queen's Medical Centre in Nottingham, England.

In the fingerprinting technique, scientists essentially countthe number of times a particular sequence of DNA base pairs (the chemical building blocks of the DNA molecule) repeats in sections of DNA (SN: 12/21&28/85, p.390). The base-pair arrangement of these sections varies so much among individuals that even close relatives can be distinguished with this technique. And since parents pass down part of their variability patterns to their offspring, parentage can also be accurately determined.

When applied to wild sparrows, the technique enabledWetton's group and researchers at the University of Leicester in Britain to unravel family genealogies as steamy as the most risque soap operas: They found evidence of incestuous  relationships and "extramarital' affairs.