The small body size associated with the African pygmy phenotype is probably a selective adaptation for rainforest hunter-gatherers, according to a new study, but since all African pygmy phenotypes do not have the same genetic underpinning it is likely a more recent adaptation than previously thought, according to a new paper in the Proceedings of the National Academies of Science.

 A phenotype is the outward expression of genetic makeup and while two individuals with the same phenotype may look alike, their genes may differ substantially. The pygmy phenotype exists in many parts of Africa, Southeast Asia, the Philippines and perhaps South America and is usually associated with rainforest hunter-gathers rather than people who farm.

The "Great Recession" and over 90 million Americans unemployed has impacted everything except the stock market and hole sales of wealthy elites, but 40 percent of elders reported a decrease in "financial strain" between 2006 and 2010.  

Men and women differ in plenty of ways,and scientists have long known that genetic differences buried deep within our DNA underlie these distinctions but past research has primarily focused on understanding how the genes that encode proteins act as sex determinants. In a new Genetics paper, scientists show that a subset of very small genes encoding short RNA molecules -
miRNAs
- also play a key role in differentiating male and female tissues in the fruit fly. 

A miRNA is a short segment of RNA that fine-tunes the activation of one or several protein-coding genes. miRNAs are able to silence the genes they target and, in doing so, orchestrate complex genetic programs that are the basis of development.

The downside to electric cars is both cost and driving range. Cost simply takes time and adoption; as has been shown in every technology from agriculture to computers, it only gets affordable for the masses after enough rich people have uptake. Driving range is a show-stopper for many, though. The stories in Silicon Valley of 'charge rage', where employees at companies are firing off angry emails at each other over available plugs rather than working, have made fewer companies want to install charging stations at all. But without them, many people can't get home.

Heterosexual white women in America were twice as likely as racial or sexual minority women to obtain medical help to get pregnant, according to an analysis of surveys from 2002 and 2006.

Will political involvement in health care coverage make the difference now? In some cases. Health insurance coverage was listed as a key factor for lesbian women but not minority women. Surveys taken today would likely have a dramatically different result, with everyone who wants an option covered insisting they can't do it unless it's in their health insurance plan.

As children learn arithmetic, they gradually switch from solving problems by counting on their fingers to pulling facts from memory. That comes more easily for some kids than for others and no one knows why but new brain images and a longitudinal provide some clues to how the brain reorganizes itself as children learn math facts.