A team of researchers at Yale University, led by evolutionary biologist Stephen Stearns, studied 2238 post-menopausal women chosen from the Framingham Heart Study - which has tracked the medical history of the residents of Framingham, Massachusetts since 1948 - to see whether factors like height, weight or cholesterol impacted the number of children women had. Even with other, social, factors accounted for, the team found that on average, shorter, heavier women with lower cholesterol tended to have more children, and started having children earlier... and that they also tended to pass these traits onto their daughters. But what does this mean? According to Stearns, a lot:

If these trends continue for 10 generations, Stearns calculates, the average woman in 2409 will be 2 centimetres shorter and 1 kilogram heavier than she is today. She will bear her first child about 5 months earlier and enter menopause 10 months later.

2 centimeters in four hundred years? Natural selection may have an destination, but it's clearly not in any rush to get there.

Meet future woman: shorter, plumper, more fertile [New Scientist]

Published this week in Nature, the new study shows that even when a group of creatures is not separated by mountain ranges, and isn't forced to find a niche in the ecosystem via natural selection, new species will evolve over hundreds of generations. The researchers created a mathematical model of speciation, when one species evolves into many, which tracks emergence of species over 2,000 generations. The model was based on scientific observation of how new species have evolved all over the Earth.

Above, you can see the model, showing how species transform over time. Each color represents a species. What begins as a uniform single-color group slowly evolves into several distinct species. But this occurs via mutation and sexual selection, not from the creatures growing distant from each other geographically. And not from competing for different niches in the environment. In this model, there are no niches and no geographical boundaries.

So what's the big deal? In short, it means that new species can arise without competion for environmental resources. Sexual selection alone is enough to produce species diversity.

According to the New England Complex Systems Institute, which funded the study:

The study found that over generations the genetic distance between organisms in different regions increases, and groups of organisms spontaneously form groups that can no longer mate, causing a patchwork of species across the area. The number of species increases rapidly until it reaches a relatively steady state.

"One can think about the creation of species on the genetic level in the same way we think about the appearance of many patterns, including traffic jams," said [researcher] Yaneer Bar-Yam. "While the spatial environment may vary, specific physical barriers aren't necessary. Just as traffic jams can form from the flow of traffic itself without an accident, the formation of many species can occur as generations evolve across the organisms' spatial habitat."

The study authors are not claiming that enviroment is unimportant. They are simply saying that under some circumstances, it is not a necessary ingredient for evolutionary transformation.

Nevertheless, this study overturns the typical view of evolution. It turns out that we don't need adaptation to a hostile natural environment to evolve new forms of life. We can do it just by having offspring and mutating over time.

via Nature and New England Complex Systems Institute

The Barcelona-based international conservation agency publishes its Sampled Red List Index to give a quick representation of trends in the natural selection market (graphic from New Scientist). Only 2.5 percent of all known plants and animals have been documented, and while that number might be a bit misleading, the process for seeing exactly which species were in danger was a cumbersome one. IUCN uses random samplings of 1500 species to assess larger risk. While cruder, such estimates can give a quick idea of the threat level before it's too late.

As you can see, the danger is most pressing in the mammalian sector. Although humpback whales are swimming back from extinction, many precious mammalian species are at risk. Marine mammals are the usual target, specifically those in northern oceans, according to an article that appeared in Science.

Viewing animals like shares reveals vanishing species [New Scientist]