Ever since Darwin, biologists have recognized that life evolves. But in the past 25 years, some researchers have argued that certain organisms are better at evolving than others. Their genomes have a flexibility that lets them adapt effectively. The less evolvable species, by contrast, are too rigid to take advantage of new mutations or to find new solutions for survival.

Many biologists agree that evolvability makes sense in theory. But finding evidence of it in the natural world has proved difficult.

Continue reading “Tortoise and Hare, in a Laboratory Flask” →

When humans domesticated dogs at least 10,000 years ago, an apparent side effect was a bizarre new kind of parasite. A canine cancer gained the ability to spread from one dog to the next, creating new tumors along the way.

Today, it thrives in dog populations around the world. Scientists are now studying canine transmissible venereal tumors (or C.T.V.T.) to uncover the adaptations the disease uses to thrive in its peculiar way. In the current issue of Science, British scientists report that it upgrades its energy supply by stealing new parts from its canine hosts.

Continue reading “Canine Tumor Fuels Up by Stealing Parts From Host, Report Says” →

If you want to appreciate the diversity of life on earth, you will need a microscope.

There are about 5,400 species of mammals on the planet, but just a spoonful of soil may contain twice as many species of microbes. They can dwell in habitats where so-called higher life forms like us would quickly die, including acid-drenched mines and Antarctic deserts. By one rough estimate, there may be, all told, 150 million species of microbes.

“Microbes represent the vast majority of organisms on earth,” said Hans-Peter Klenk, a microbiologist for the German Collection of Micro-organisms and Cell Cultures, a government microbiology research center.

Continue reading “Scientists Start a Genomic Catalog of Earth’s Abundant Microbes” →