Health & Science

Is all language out of Africa?

The world’s 6,000 languages are all descended from a single ancestral tongue that developed in southern Africa between 50,000 and 100,000 years ago. That’s the intriguing new theory developed by University of Auckland psychologist Quentin Atkinson, after he sorted 504 modern languages by the number of phonemes—basic vowel, consonant, and tonal sounds—they use to convey meaning. He found that in Africa—where humans originated, according to fossil and DNA evidence—some languages contain more than 100 phonemes, compared with about 45 in English. Languages in the last places settled by humans have the fewest phonemes; Hawaiian, for instance, has only 13. That linguistic pattern parallels what evolutionary geneticists call the “founder effect”—the tendency of smaller groups to keep narrowing the diversity of a larger population when they move away. Atkinson’s approach is a radical departure from historical linguistics, which can trace languages back only about 9,000 years. “What’s so remarkable about this work is that it shows language doesn’t change all that fast,” Mark Pagel, a biologist at the University of Reading in England, tells The New York Times. “It retains a signal of its ancestry over tens of thousands of years.”

Pluto’s changing atmosphere

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Pluto, our solar system’s famous orbiting outlier, is not the frozen, dead world scientists once imagined. In fact, recent observations reveal, it has an atmosphere that changes dramatically over time. A decade ago scientists found that Pluto’s atmosphere extended only about 62 miles beyond its surface and contained only trace amounts of carbon monoxide. Today, the atmosphere has expanded to almost 2,000 miles out, and its carbon monoxide level has doubled. The changes may have begun when Pluto reached the closest point to the sun during its 248-year elliptical orbit. The tiny amount of extra solar heat may have turned liquid carbon monoxide, methane, and nitrogen on the orb’s icy surface into gas. Strong solar winds could also have blown the atmosphere farther out into space. Since scientists only discovered Pluto 80 years ago, they haven’t yet witnessed even a third of its seasonal changes. “It’s all a bit of a puzzle,” Jane Greaves, an astrobiologist at the University of St. Andrews in Scotland, tells Science. “We’re seeing everything happen for the first time.”

Three ecosystems of the gut

About a century ago, scientists discovered that human beings have several distinct blood types. New research has found that everyone also has one of three distinct families of intestinal bacteria, and that these types may strongly affect everything from how well we digest food to how medicines work in different people. European researchers analyzed microbial ecosystems found in stool samples from Japan, the U.S., and four European countries. They identified three “enterotypes’’ that appear unrelated to an individual’s ethnic background, age, sex, health, or weight. Which particular enterotype takes hold in the gut may depend on which species of microbe was able to establish itself there first in infancy. The discovery of three specific types “was a surprise, and it’s good news,” researcher Peer Bork tells Bloomberg.com. Bork says the findings could lead to greater precision in diagnosing bowel and digestive disorders, and a new understanding of why the effects of different medicines and nutrients can vary widely from person to person. Someday, in fact, doctors may find it as important to know people’s intestinal enterotypes as they do blood types today.

The humpback top 40

Male humpback whales are avid singers, and some of their tunes turn into undersea hits. Scientists have discovered that the giant baleens have a complex musical culture, developing popular songs that rapidly spread from pod to pod across the ocean. “It’s a culturally driven change across a vast scale,” University of Queensland researcher Ellen Garland tells BBCNews​.com. The latest hit is usually a variation on a classic, “like splicing an old Beatles song with U2,” Garland says. Other times, though, the whales arrange their high-pitched cries, moans, groans, and growls into an original refrain. Researchers analyzed 745 songs performed by Pacific whales over 11 years, and found that new songs tended to originate with the westernmost, Australian whale group. Then the tunes traveled east, often reaching French Polynesia, some 4,000 miles away, within two years. The males’ “quest for song novelty,” Garland says, is driven by “the hope of being that little bit different and perhaps more attractive to the opposite sex.”