Science Briefs

Did farming make humans couch potatoes ?

Put under stress through physical exertion – such as long-distance walking or running – human bones gain in strength as the fibers are added or redistributed according to where strains are highest. Because the structure of human bones can inform us about the lifestyles of the individuals, they can provide valuable clues for biological anthropologists. Research by Alison Macintosh, a doctoral candidate at Britain’s Cambridge University, shows that after the emergence of agriculture in Central Europe from around 5300 B.C., the bones of those living in the fertile soils of the Danube river valley became progressively less strong.

Work published by Cambridge biological anthropologist Colin Shaw enabled Macintosh to interpret this male decline in relation to Cambridge University students. Using Shaw’s study of bone rigidity among modern Cambridge undergrads, Macintosh suggests that male physicality mobility among earliest farmers (around 7,300 years ago) was, on average, at a level near that of today’s student cross-country runners. Within just over 3,000 years, average mobility had dropped to the level of those students rated as sedentary, after which the decline slowed.

Humans may be born with language skills

Humans are unique in their ability to acquire language. But how? A study published in the Proceeding of the National Academy of Sciences suggests we are born with the basic fundamental knowledge of language.

Certain aspects appear to be shared across languages and might stem from linguistic principles that are active in all human brains. A natural question then arises: Are infants born with knowledge of what the human words might sound like?

“The results of this new study suggest that the sound patterns of human languages are the product of an inborn biological instinct, very much like birdsong,” said Iris Berent of Northeastern University in Boston, who co-authored the study with a research team from the International School of Advanced Studies in Italy.

Advance warning systems help drivers

Most drivers have experienced a traffic signal that turns yellow just as they approach an intersection, which makes it difficult for them to decide whether to stop or proceed through it. The wrong choice in this situation may lead to crashes, especially at high-speed intersections. A major factor making driving difficult is hazards that are sudden and hard to predict.

Roadside and in-vehicle display warning systems may help drivers handle these hazards by predicting their occurrence and providing a warning to the driver, according to a new study published in the journal Human Factors.

Clemson University psychology professor Leo Gugerty and his colleagues designed two driving simulator studies to compare the effectiveness of six types of roadway or in-vehicle warning systems. Participants were asked to navigate through traffic lights while their driving responses were measured based on the presence or absence of warning signals.

“In both studies, warnings led to more stopping at ‘dilemma zone’ intersections and milder decelerations when stopping compared with no warning,” said Gugerty, lead author on the paper. “Drivers’ predominant response to warnings was anticipatory slowing on approaching the intersection, not speeding up.”