# Random Samples

Science  25 Nov 2005:
Vol. 310, Issue 5752, pp. 1274
1. # Two Views Better Than One?

The demand by intelligent design (ID) proponents to teach the scientific “controversy” about evolution riles most scientists. But a new study suggests that including ID materials in biology classes may help open minds to evolution.

During the fall of 2003, 103 freshman biology majors at Central Washington University in Ellensburg were divided into four sections. Two, taught by biologist Steven Verhey, learned arguments for both ID and evolution, with readings from evolutionary biologist Richard Dawkins's The Blind Watchmaker and Icons of Evolution by ID proponent Jonathan Wells. The other two read only Matt Ridley's The Red Queen, about the evolution of sex and human nature.

At the end of the semester, 66 of the students agreed to take an anonymous survey in which they classified their beliefs before and after the course into six categories, ranging from biblical literalism to atheistic evolutionism. Verhey reports in the November issue of BioScience that 61% of the respondents exposed to both ID and evolution indicated a change of mind, as opposed to 21% in the control sections. The great majority of shifters moved toward evolution. For example, four of six in the experimental group who identified themselves as biblical literalists moved in the “rationalist” direction, Verhey reports.

The study provides “powerful evidence” that directly engaging students' beliefs, rather than ignoring them, may be an effective way to teach evolution, writes biologist Craig Nelson of Indiana University, Bloomington, in an accompanying editorial. But he agrees with evolutionary geneticist Jerry Coyne of the University of Chicago that this strategy wouldn't be appropriate for high school students, who, says Coyne, “are not intellectually equipped to deal with such [a] controversy.”

2. # Fight or Flight

Anger is better for your health than fear, say researchers. The two emotions are generally lumped together when it comes to stress-related health risks. But psychiatrist Jennifer Lerner of Carnegie Mellon University in Pittsburgh, Pennsylvania, and colleagues have devised a way to sort them out through analysis of facial expressions.

The researchers studied 92 subjects who counted backward and did math problems while an experimenter verbally harassed them. To determine the participants' emotions during testing, the researchers used a system that tracks facial muscle movements known to be correlated with fear or anger.

Measurements taken during the testing showed that blood pressure and saliva levels of the stress hormone cortisol went up in all participants expressing fear from the unreasonable pressure. But those physiological responses were much less pronounced among those whose faces indicated anger instead, the researchers reported in last month's issue of Biological Psychiatry. This makes sense to Lerner: Whereas fear implies loss of control, anger suggests that action can be taken, she explains.

Because it's hard to trust the emotions described by a participant under stress, Lerner says, the facial-analysis technique has “enormous potential for getting a window on emotion.” Correlating facial expressions with biological responses to stress is “really cool,” says psychiatrist Reginald Adams of Pennsylvania State University, University Park. “It's such a versatile tool. It's going to open up some very exciting directions for future research.”

3. # Flying Noses

Wasp in training.

Hunting for dead bodies or hidden explosives? A tube of wasps may be the answer for both types of unusual searches. In the wild, the tiny parasitic wasp Microplitis croceipes can smell not only nectar but also airborne chemical signals from plants being eaten by its host caterpillar.

Entomologist W. Joe Lewis of the U.S. Department of Agriculture's Agricultural Research Service found he could train the wasps to link many scents with a sugar-water reward. But “you can't put a wasp on a leash and take it around” like a bomb-sniffing dog, he says. So engineer Glen Rains of the University of Georgia, Tifton, designed a portable “Wasp Hound”: a device outfitted with a fan that pulls air through a cartridge holding five wasps. When they catch a whiff of a target scent, say, 2,4-dinitrotoluene from explosives, they crowd around the air holes, looking for a reward.

In a recent test using five different smells, the device far outperformed an electronic nose and was as good as a dog, the researchers report in an upcoming issue of Biotechnology Progress. But wasps are cheaper than bloodhounds and need only 5 minutes of training, Lewis says. Now, Rains and Lewis are working on a mass wasp-training regimen and on new applications including finding dead bodies from scents such as cadaverine and putrescene.

Bees are also joining the olfactory workforce. Bee specialist Mathilde Briens, of Inscentinel in Harpenden, U.K., says they're working on a system in which bees stick out their tongues in response to a scent.