Many Europeans carry genetic mutations that protected their ancestors from the bubonic plague, scientists reported on Wednesday in the journal Nature.

When the Black Death struck Europe in 1348, the bacterial infection killed large swaths of people across the continent, driving the strongest pulse of natural selection yet measured in humans, the new study found.

It turns out that certain genetic variants made people far more likely to survive the plague. But this protection came with a price: People who inherit the plague-resistant mutations run a higher risk of immune disorders such as Crohn’s disease.

Continue reading “How the ‘Black Death’ Left Its Genetic Mark on Future Generations” →

Scientists have successfully transplanted clusters of human neurons into the brains of newborn rats, a striking feat of biological engineering that may provide more realistic models for neurological conditions such as autism and serve as a way to restore injured brains.

In a study published on Wednesday, researchers from Stanford reported that the clumps of human cells, known as “organoids,” grew into millions of new neurons and wired themselves into their new nervous systems. Once the organoids had plugged into the brains of the rats, the animals could receive sensory signals from their whiskers and help generate command signals to guide their movements.

Continue reading “Human Brain Cells Grow in Rats, and Feel What the Rats Feel” →

Look up an image of a tumor on Google, and you’ll probably end up with a brightly colored cluster of cancer cells on a drab background of healthy tissue. But for Lian Narunsky Haziza, a cancer biologist at the Weizmann Institute of Science in Israel, the picture looks very different. A tumor may also contain millions of microbes, representing dozens of species.

“I think this is an ecosystem,” she said. “It means the cancer cells are not alone.”

Continue reading “A New Approach to Spotting Tumors: Look for Their Microbes” →