In a limestone cave nestled high above the Anuy River in Siberia, scientists have discovered the fossil of an extraordinary human hybrid.

The 90,000-year-old bone fragment came from a female whose mother was Neanderthal, according to an analysis of DNA discovered inside it. But her father was not: He belonged to another branch of ancient humanity known as the Denisovans.

Scientists have been recovering genomes from ancient human fossils for just over a decade. Now, with the discovery of a Neanderthal-Denisovan hybrid, the world as it was tens of thousands of years ago is coming into remarkable new focus: home to a marvelous range of human diversity.

Continue reading “A Blended Family: Her Mother Was Neanderthal, Her Father Something Else Entirely” →

Elephants ought to get a lot of cancer. They’re huge animals, weighing as much as eight tons. It takes a lot of cells to make up that much elephant.

All of those cells arose from a single fertilized egg, and each time a cell divides, there’s a chance that it will gain a mutation — one that may lead to cancer.

Strangely, however, elephants aren’t more prone to cancer than smaller animals. Some research even suggests they get less cancer than humans do.

Continue reading “The ‘Zombie Gene’ That May Protect Elephants From Cancer” →

About 50 million years ago, dog-like mammals returned to the seas, eventually evolving into whales and dolphins. Around then, too, an early cousin of elephants took the plunge, giving rise to manatees and dugongs.

About 20 million years later, bearlike mammals also waded back into the sea, evolving into seals, sea lions and walruses.

Each of these marine species adapted to the aquatic life in its own way. Manatees and dugongs slowly graze on sea grass. Seals and their relatives dive deep underwater after prey, but still haul themselves onto beaches to mate and rear pups.

Continue reading “Marine Mammals Have Lost a Gene That Now They May Desperately Need” →