The missing word on whale evolution:

The missing word on whale evolution: Indohyus
Scientists who study evolution have long known that whales must have had ancestors that lived on land. Some characteristics were dead giveaways, most notably the fact that they are air-breathers. But fossil evidence of the transition wasn8217;t found until the mid-1990s, when Hans Thewissen, a professor of anatomy at Northeastern Ohio Universities College of Medicine, and others described 50-million-year-old fossils of extinct whales with hind limbs. 8220;It was clear they could walk on land,8221; Thewissen said.
What was still missing was the closest non-whale ancestor, the animal that was the link to these early whales. Now Thewissen and colleagues are reporting in Nature that they8217;ve found the link. It8217;s Indohyus, a fox-size deerlike animal that lived in what is now India and Pakistan at around the same time as the earliest whales. The animal, of the order artiodactyla, the even-toed ungulates, has been known for about two decades, but it wasn8217;t until Thewissen examined fossils from Kashmir that he realised certain characteristics of the animal8217;s skeleton tied it to whales. Modern and ancient whales have a bone in their ear that is a half-sphere, thick on the outside and thin on the inside, the better to hear underwater. 8220;Indohyus has that,8221; Thewissen said. 8220;It8217;s the first non-whale to have that. That8217;s the most spectacular piece of evidence.8221;
Further indication of the link to whales was found in the structure of some if its teeth, he said. Other evidence suggests that the animal might have spent at least part of its time in water. Thewissen said his work showed hippopotamids might be the modern sister group of whales, but they go back only 15 million years. Indohyus8217; age is more in line with early whale evolution. 8220;It8217;s closer to whales but doesn8217;t have extant relatives,8221; he said. NYT

With bad tattoo inks, etching may lead to itching
A slew of cable TV shows featuring tattoo shops have raised the profile of body art. While the risks associated with dirty needles, which can spread HIV and hepatitis, are widely known, how about the ink that8217;s injected into the skin? From 2003 to mid-2006, the US Food and Drug Administration received more than 150 complaints of skin irritation tied to 8220;permanent makeup8221; tattoos. In particular, complaints have been linked to certain colours by Premier Pigments, used when tattooing lip liner, eyeliner and eyebrows, according to the agency. Premier8217;s president, Sandi Hammons, called allergic reactions 8220;very, very rare8221; and treatable. 8220;Many pigments used in tattoo inks are not approved for skin contact at all,8221; the FDA said last year. 8220;Some are industrial-grade colours that are suitable for printers8217; ink or automobile paint.8221; The agency8217;s National Center for Toxicology Research is studying whether the ink gets into body tissues or the bloodstream when tattoos are exposed to sunlight or removed by lasers. LAT-WP

Singing to a different tune
Practice may not really make perfect. A virtuoso musician may seem to nail every note, but there are tiny variations in even the most skilled performance. These variations in fine motor movements may represent the nervous system8217;s equivalent of a bit of static on a phone line: something that can8217;t be completely controlled but is nothing to really worry about either. But another line of thinking suggests that subtle variability might be useful, because it forces the nervous system to adjust, and to learn through trial and error which adjustments are an improvement and which are not, thus maintaining an optimal performance.
This possibility was explored by Evren C. Tumer and Michael S. Brainard of the University of California, San Francisco, using another virtuoso performer: an adult male songbird, the Bengalese finch. Like many other songbirds, these finches develop their song as juveniles. They practice over and over until, as an adult, the song becomes set. But even a stable adult song has slight variations in pitch or other characteristics. To see if the birds could make adjustments, the researchers devised an experiment using a computerised system that detects slight variations in pitch in the song. When such a 8220;mistake8221; is made, the normal feedback the bird hears its own song is disrupted by a burst of white noise. The birds soon began to shift their pitch8212;to 8220;correct8221; their mistakes8212;to avoid the disruption. Researchers say the findings show that variations force the bird to learn and adjust8212;an ability that might help it maintain the quality of its song as its motor skills decline because of ageing or injury. NYT