These findings indicate that the human brain reacts differently to these potential pheromones compared with common odors, suggesting a link between sexual orientation and brain function.

Women Migrate More than Men, Based on Society

A newly published study shows that immigration rates differ between genders and follow societal rules, with women moving more often than men overall.

Laurent Excoffier and colleagues analyzed previously published genetic data with a statistical method that allows estimation of male- and female-specific migration rates.

The study focused on two kinds of societies in Northern Thailand. In patrilocal societies, a woman moves to the village of her new husband. In matrilocal societies, a man moves to the village of his new wife.

The researchers examined how this dispersal of the sexes affects the gene pool of the different populations. They studied mitochondrial DNA and genes from the Y chromosome, sex-specific tracers of females and males, respectively, from three matrilocal and three patrilocal populations. The analysis provided the rate of sex-specific immigration into the different societies.

Interestingly, men and women moved at about the same rate within matrilocal societies, but women moved far more than men in patrilocal groups.

The results suggest that while men are strictly controlling immigration in traditional patrilocal populations, the process is much less regulated in matrilocal communities. The results further suggest that genetic analysis can give insight into human social structure.

Blood Test for Ovarian Cancer

Researchers have developed a blood screening test that could help catch ovarian cancer in its early stages, when few symptoms are present. <
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Contact: Leikny Johnson
PNASNews@nas.edu
202-334-1310
Proceedings of the National Academy of Sciences (PNAS)
9-May-2005