What color were dinosaurs? Well, at least one of them had a feathered mohawk tail in a subdued palette of chestnut and white stripes.

That is what a team of Chinese and British scientists reported Wednesday in Nature, providing the first clear evidence of dinosaur colors from studies of 125-million-year-old fossils of a dinosaur called Sinosauropteryx.

“We might be able to start painting a picture in color of what these things looked like,” said Lawrence M. Witmer, a paleontologist at Ohio University, who was not involved in the study.

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The borna virus is at once obscure and grotesque. It can infect mammals and birds, but scientists know little about its effects on its victims. In some species it seems to be harmless, but it can drive horses into wild fits. The horses sometimes kill themselves by smashing in their skulls. In other cases, they starve themselves to death. Some scientists have even claimed that borna viruses alter human behavior, playing a role in schizophrenia and bipolar disorder, although others say there is no solid evidence of a link.

The virus now turns out to have an intimate bond with every person on Earth. In the latest issue of Nature, a team of Japanese and American scientists report that the human genome contains borna virus genes. The virus infected our monkey-like ancestors 40 million years ago, and its genes have been passed down ever since.

Continue reading “Hunting Fossil Viruses in Human DNA” →

Evolution is a virus’s secret weapon. The virus can rapidly slip on new disguises to evade our immune systems, and it can become resistant to antiviral drugs.

But some scientists are turning the virus’s secret weapon against it. They hope to cure infections by forcing viruses to evolve their way to extinction.

Viruses can evolve because of the mistakes they make when they replicate. All living things can mutate, but viruses are especially prone to these genetic errors. In fact, some species of viruses mutate hundreds of thousands of times faster than we do.

Continue reading “Using a Virus’s Knack for Mutating to Wipe It Out” →