For centuries, archaeologists have reconstructed the early history of Europe by digging up ancient settlements and examining the items that their inhabitants left behind. More recently, researchers have been scrutinizing something even more revealing than pots, chariots and swords: DNA.

On Wednesday in the journal Nature, two teams of scientists — one based at the University of Copenhagen and one based at Harvard University — presented the largest studies to date of ancient European DNA, extracted from 170 skeletons found in countries from Spain to Russia. Both studies indicate that today’s Europeans descend from three groups who moved into Europe at different stages of history.

Continue reading “DNA Deciphers Roots of Modern Europeans” →

Before the end of the last Ice Age, saigas roamed by the millions in a range stretching from England to Siberia, even into Alaska. Eventually they moved to the steppes of Central Asia, where they continued to thrive — until the 20th century, when these strange-looking antelopes began flirting with extinction.

Hunted for its horns, 95 percent of the population disappeared, and the saiga was declared critically endangered.

After the implementation of strict antipoaching measures, the population recovered, from a low of 50,000 to about 250,000 last year. “It was a big success story,” said Eleanor J. Milner-Gulland, the chairwoman of the Saiga Conservation Alliance.

Continue reading “Death on the Steppes: Mystery Disease Kills Saigas” →

For scientists who study human evolution, the last few months have been a whirlwind. Every couple of weeks, it seems, another team pulls back the curtain on newly discovered bones or stone tools, prompting researchers to rethink what we know about early human history.

On Wednesday, it happened again. Yohannes Haile-Selassie of the Cleveland Museum of Natural History and his colleagues reported finding a jaw in Ethiopia that belonged to an ancient human relative that lived sometime between 3.3 and 3.5 million years ago. They argue that the jaw belongs to an entirely new species, which they named Australopithecus deyiremeda.

Continue reading “The Human Family Tree Bristles With New Branches” →

Octopuses, squid and cuttlefish — a group of mollusks known as cephalopods — are the ocean’s champions of camouflage.

Octopuses can mimic the color and texture of a rock or a piece of coral. Squid can give their skin a glittering sheen to match the water they are swimming in. Cuttlefish will even cloak themselves in black and white squares should a devious scientist put a checkerboard in their aquarium.

Cephalopods can perform these spectacles thanks to a dense fabric of specialized cells in their skin. But before a cephalopod can take on a new disguise, it needs to perceive the background that it is going to blend into.

Continue reading “For an Octopus, Seeing the Light Doesn’t Require Eyes” →