In 2010, scientists made a startling discovery about our past: About 50,000 years ago, Neanderthals interbred with the ancestors of living Europeans and Asians.

Now two teams of researchers have come to another intriguing conclusion: Neanderthals interbred with the ancestors of Asians at a second point in history, giving them an extra infusion of Neanderthal DNA.

The findings are further evidence that our genomes contain secrets about our evolution that we might have missed by looking at fossils alone. “We’re learning new, big-picture things from the genetic data, rather than just filling in details,” said Kirk E. Lohmueller, a geneticist at the University of California, Los Angeles, and co-author of one of the new studies.

Continue reading “A New Theory on How Neanderthal DNA Spread in Asia” →

In 2010, a graduate student named Tamar Gefen got to know a remarkable group of older people.

They had volunteered for a study of memory at the Feinberg School of Medicine at Northwestern University. Although they were all over age 80, Ms. Gefen and her colleagues found that they scored as well on memory tests as people in their 50s. Some complained that they remembered too much.

She and her colleagues referred to them as SuperAgers. Many were also friends. “A couple tried to set me up with their grandsons,” Ms. Gefen said.

Continue reading “Studying Oversize Brain Cells for Links to Exceptional Memory” →

In the closing sentence of “The Origin of Species,” Charles Darwin marvels at the process of evolution, observing how “from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.”

Few people would describe bedbugs as most beautiful or most wonderful. Yet this blood-feeding pest may represent an exceptional chance to observe the emergence of Darwin’s “endless forms”: New research indicates that some bedbugs are well on their way to becoming a new species.

Continue reading “In Bedbugs, Scientists See a Model of Evolution” →