Supernovas got humans walking
Early humans may have evolved to walk on two feet because exploding stars destroyed their forest habitats, a new study suggests. Our corner of the Milky Way experienced a series of supernovas that peaked about 2.6 million years ago, says researchers at the University of Kansas. The radiation blasting out from these dying stars ionized Earth’s atmosphere, making it more conductive— which led to lightning strikes that sparked massive wildfires in Africa’s forests. At that point, our ancient tree-dwelling ancestors lived their lives on all fours, clambering up trunks and swinging from branch to branch. But “when the forests are replaced with grasslands,” co-author Adrian Melott tells The Guardian (U.K.), “it then becomes an advantage to stand upright, so you can walk from tree to tree and look over the tall grass for predators.” The researchers’ evidence for the lightning strikes is a layer of highly ionized iron deposits found across the ocean floor; as for the wildfires, the scientists point to carbon deposits in soils that can be dated back to the time of the supernovas. “There’s a lot more charcoal and soot in the world starting a few million years ago,” says Melott. “This could be an explanation.”
grown children to produce grandkids, but bonobo moms take the pressure to a whole new level. These moms are so determined to become grandmothers that they will stand by when their sons mate with a female and fight off any other males that try to disrupt the lovemaking. These overbearing ape moms also run interference, breaking up liaisons between females and males that aren’t their sons. Occasionally, mother and son even team up to attack the latter’s sexual rivals. This forceful maternal behavior is well documented, and a new study has concluded for the first time that it actually helps the sons thrive, reports DiscoverMagazine. com. Researchers found that wild male bonobos in Congo whose mothers were still with them fathered three times more offspring than bonobos whose mothers had died or left the group. Lead author Martin Surbeck, from the Max Planck Institute in Leipzig, Germany, says bonobo moms likely act as they do to “increase their reproductive success without having more offspring themselves.”
and their word test results by 1 percent. Men, however, answered fewer questions as the temperature went up and gave fewer correct answers. The subjects were all wearing roughly the same clothes, suggesting the disparity may be biological rather than sartorial. The findings, say the study authors, “suggest that in gender-balanced workplaces, temperatures should be set significantly higher than current standards.”