# Random Samples

Science  25 Mar 2005:
Vol. 307, Issue 5717, pp. 1867
1. # A Cure for the Common Mold

After Alexander Fleming stumbled upon penicillin in 1928, a problem with his find surfaced: The mold that made the drug, Penicillium notatum, only did so in small quantities. In 1943, scientists turned to another species of mold: one discovered on cantaloupe that today churns out 1000 times more penicillin. A single genetic mutation, it now turns out, explains the cantaloupe strain's superlative production.

To make penicillin, mold first produces a precursor acid. The acid can be converted into either penicillin or another chemical, 2-hydroxy-PA, but José Luis Barredo and colleagues at Antibióticos, a pharmaceutical company in Leon, Spain, found that P. chrysogenum, the high-producing species, has a gene defect that prevents it from producing much of the latter. So it's stuck with making penicillin instead, the researchers report online this month in Fungal Genetics and Biology.

2. # Upright Ancestors From Ethiopia

Ever since the 3.1-million-year-old skeleton of Lucy was unearthed in Ethiopia 30 years ago, paleoanthropologists have wondered when and how her ancestors began walking upright. New clues may come from two recent discoveries: a well-preserved partial skeleton, dug up in February in the badlands of Ethiopia by Ethiopian paleo-anthropologist Yohannes Haile-Selassie of the Cleveland Museum of Natural History in Ohio (Science, 11 March, p. 1545), and a thighbone just announced. Both help fill a gap in the fossil record when bipedalism was evolving.

The second find, by a team led by Horst Seidler of the University of Vienna, was discovered at an Ethiopian site called Galili. The thighbone (photo, left) reveals an individual who walked upright, but perhaps differently than did Lucy (photo, right) and the original owner of a 6-million-year-old thighbone from Kenya, whose discoverers say it walked with a modern gait.

Muscles and ligaments appear to have attached differently to the thighbone than in Lucy's species, Australopithecus afarensis, suggesting a different walk, says anthropologist Gerhard Weber of the University of Vienna. That could mean early hominids didn't all evolve to walk upright in the same way. But the thighbone is rebuilt from 26 fragments, so its gait may be tough to discern.

3. # Big Brains Rule the Roost

When it comes to brains, people naturally assume bigger is better. But why should size matter? Now an international team of researchers has shown that a popular hypothesis may be right: In birds, at least, a bigger brain makes it easier to adapt to a new environment.

The team, which included biologists Daniel Sol of the Center for Ecological Research and Applied Forestry in Barcelona, Spain, and Louis Lefebvre of McGill University in Montreal, Canada, analyzed an existing database of the results of 645 attempts by humans to introduce 195 bird species to new places, such as an island or a different continent. In 243 of the attempts, the birds established a self-sustaining population. The bigger the species' brain relative to its body size, the better it was at overcoming challenges of a new environment such as finding food or avoiding predators, the team reports this week in the online early edition of the Proceedings of the National Academy of Sciences. Members of the parrot family, which have a very large relative brain size, had a particularly easy time of it, succeeding on average 200% more often than members of the partridge and pheasant families, with their small relative brain sizes.

The new study is an “exciting marriage between ecology and psychology,” says behavioral biologist Simon Reader of the University of Utrecht in the Netherlands.

4. # Smart Robot

Rolling over Chile's Atacama Desert, the robotic rover Zoë (below) snapped dozens of fluorescent photographs that helped document the presence of life—microorganisms—in this forbidding environment, a team at Carnegie Mellon University and NASA's Ames Research Center reported last week at the Lunar and Planetary Science Conference in Houston, Texas. To map the distribution of microbes, Zoë spent 2 months in the Chilean desert last fall. Scientists accompanied her in part so that she didn't “drive off a cliff,” says David Wettergreen, a Carnegie Mellon roboticist and the project leader. The robot's pictures, which can detect chlorophyll and DNA, correlated with soil samples the scientists took to confirm that Zoë's results were accurate. Next field season, the team hopes Zoë will chug over 200 km of desert—up from 30 km last year—and shed light on the extreme environmental conditions in which life can still flourish. They're also working with NASA to apply Zoë's technology to extraterrestrial robots.

5. # Politics

Law-abiding. A controversy over a German scientific prize awarded to the creator of Dolly has been defused after Ian Wilmut promised not to use the money for cloning.

Wilmut, a researcher for more than 30 years at the Roslin Institute in Edinburgh, U.K., received the $134,000 Paul Ehrlich and Ludwig Darmstaedter prize last week at a ceremony that was picketed by sheep-costumed protesters. They noted that his work on creating human cell lines using nuclear transfer would be illegal in Germany, which forbids all forms of human cloning. Wilmut says the prize money—half of which comes from the German government—will only support attempts to piece together the molecular processes behind nuclear reprogramming in mice. And the work may not be done at Roslin: Wilmut told reporters before the event that he was leaving the institute this summer. He declined to name his new employer. 6. # Awards New heights. The two researchers who share this year's$200,000 Tyler Prize for Environmental Achievement reached for the sky to take the pulse of the climate system and, ultimately, raise awareness of the global warming threat.

In 1958, atmospheric chemist Charles Keeling (left) of the Scripps Institution of Oceanography in La Jolla, California, went to the top of Hawaii's 4170-meter Mauna Loa to see what the burning of fossil fuels was doing to the atmosphere. Within a few years Keeling's lengthening record of precisely measured carbon dioxide, now known as the “Keeling curve,” had revealed the seemingly inexorable accumulation of the greenhouse gas in the atmosphere. By committing to meticulous analysis of a neglected trace gas, says atmospheric scientist Stephen Schwartz of Brookhaven National Laboratory in Upton, New York, the now-retired Keeling “has changed the world.”

Paleoclimatologist Lonnie Thompson (right) of Ohio State University in Columbus has trudged up to glaciers as high as 7200 meters to drill out millennia-long climate records from tropical ice (Science, 18 October 2002, p. 518). They have helped him show that the tropics suffer far larger climatic swings than scientists had suspected. His next goal: Bring back ice from more tropical mountain glaciers before global warming melts them.