On the horizon: News from the frontiers of science.
The whale's tiny ancestor, how global warming may be hurting plants' carbon-fixing ability, and the mystery of Mars's missing limestone
A whale of a fox tale
A team led by paleontologist Hans Thewissen says it has found the closest known fossil relative of whales – a four-hoofed creature that had an even number of toes, looked a bit like a miniature deer, and appears to have spent a great deal of time wading in shallow waters some 48 million years ago.
For more than 100 years, scientists have amassed evidence that whales evolved from land mammals. For 15 years, Dr. Thewissen, a professor at Northeastern Ohio Universities Colleges of Medicine and Pharmacy, has uncovered a range of fossils tracing this evolutionary pathway at its geographic center – southern Asia.
The researchers say their find, dubbed Indohyus, shows striking similarities to whales in bone density, structure of ears and early molars, as well as in the oxygen-isotope content of their teeth. The results appeared recently in the journal Nature.
Global warming cools Co2 uptake
Global warming may herald longer growing seasons. But that could undercut the ability of ecosystems to take up heat-trapping carbon dioxide and store it.
That's the word from a team of scientists from Europe, China, Canada, and the United States who studied patterns in the way northern ecosystems around the globe take up and give off CO2. Over the past 20 years' worth of growing seasons, they found that the annual autumn-to-winter build-up of carbon dioxide in the atmosphere is coming earlier than it once did. This apparently is shortening the time each year when plants take up CO2.