Humans

No Neandertal hanky-panky
New mitochondrial DNA analyses indicate that Neandertals didn’t occasionally interbreed with Stone Age humans, as proposed in a recent study of Neandertal nuclear DNA, say evolutionary biologist Guido Barbujani of the University of Ferrara in Italy and his colleagues. Barbujani’s team analyzed maternally inherited mitochondrial DNA from European Neandertals, Stone Age Europeans and living Europeans. If nuclear DNA lines leading to Neandertals and Europeans are older than corresponding mitochondrial DNA lines, then a long period of shared ancestry could explain why Neandertals and today’s Europeans share some nuclear DNA, the researchers propose online August 24 in the American Journal of Physical Anthropology. —Bruce Bower

Psychling dynamics
Although cyclist Alberto Contador won the 2009 Tour de France, he was criticized for defecting from his teammates and sprinting ahead when tactics demanded patience. A new analysis suggests that criticism was on mark. When strong riders break away from their companions, it helps the defector but hurts the team, researchers report in an upcoming issue of Complexity. University of Colorado at Boulder scientists and a sports psychologist from a professional team developed a bike racing model incorporating variables such as cooperation, defection, speed, distance and effort. The model nicely captures real racing dynamics: below-average riders fare better as defectors, above-average riders as cooperators, and when a strong rider does defect, it really screws his team. —Rachel Ehrenberg

Depression-fighting beliefs
Strong religious and spiritual beliefs may defend against recurrences of depression, especially if this mood disorder runs in a person’s family. Among individuals tracked for 10 years, those who considered religion and spirituality important in their lives displayed a markedly lower rate of major depression than those who didn’t, say psychologist Lisa Miller of Columbia University in New York City and her colleagues. Religion’s protective effect was greatest for those who had depressed mothers, the researchers  report online August 24in the American Journal of Psychiatry. Most of those high-risk individuals had been treated for bouts of depression before the study began. —Bruce Bower

Neandertals’ varied menu
Often portrayed as meat-obsessed big-game hunters, Neandertals may have had broader tastes. Neandertals that lived in southern France between 250,000 and 125,000 years ago ate fish, birds and starchy plants as well as wild cattle,  deer and wild horses, two anthropologists report online August 24 in PLoS ONE. Microscopic residue and edge-wear patterns on Neandertal stone tools previously unearthed at a French site called Payre reveal a varied diet that may have been missed in previous studies of butchered animal bones, say Bruce Hardy of Kenyon College in Gambier, Ohio, and Marie-Hélène Moncel of the National Museum of Natural History in Paris. —Bruce Bower