The top Republican on the Senate health committee said in a report on Thursday that the coronavirus pandemic was most likely caused by a laboratory incident in China. The report offered little new evidence, however, and was disputed by many scientists, including those whose research suggests that the outbreak originated instead at a live animal market.

The report, released by Senator Richard M. Burr, Republican of North Carolina, grew out of a joint inquiry with the committee’s Democratic chairwoman that proponents of the effort hoped would add a measure of bipartisan credibility to a highly charged debate.

Continue reading “G.O.P. Senator’s Report on Covid Origins Suggests Lab Leak, but Offers Little New Evidence” →

Scientists at Boston University came under fire this week for an experiment in which they tinkered with the Covid virus. Breathless headlines claimed they had created a deadly new strain, and the National Institutes of Health rebuked the university for not seeking the government’s permission.

As it turned out, the experiments, performed on mice, were not what the inflammatory media coverage suggested. The manipulated virus strain was actually less lethal than the original.

Continue reading “Lab Manipulations of Covid Virus Fall Under Murky Government Rules” →

The findings, published on Wednesday in the journal Nature, painted a tragic picture of our extinct relatives, who roamed Eurasia tens of thousands of years ago. The family, part of a band of 11 Neanderthals found together in the cave, most likely died together, scientists said, possibly from starvation.

Continue reading “First Known Family of Neanderthals Found in Russian Cave” →

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” →