Posts Tagged ‘science’

Moth Brains

Saturday, March 7th, 2009

Just when you think you can’t bear wading through one more impenetrable paper in a research journal, you stumble across an experiment that makes you fall in love with science all over again. Who could possibly resist the image of researchers wiring up moth brains to study how they perceive flower odors wafting through the air?

The sacred datura, an impressive (and hallucinogenic and poisonous) U.S. native perennial that produces huge, white, trumpet-shaped, and irresistibly fragrant blooms, is the favorite nectar source of the tobacco hornworm moth. To find the food, the moths must recognize the faintest whiff of datura and then track the scent upwind to the flower. In return for the meal, the moths pollinate the plant. To learn how the moth pollinator reacts to the 60 different chemicals that comprise the plant’s irresistible perfume, biology geeks at The University of Arizona in Tucson engulfed 20 flowers with Reynolds® Oven Bags and sucked the air out of the bags into a charcoal filter to capture all the chemicals. Back in the lab, they created a solution of the chemicals and injected it into a gas chromatograph. The chromatograph separated the chemicals and spewed them out one by one into a branched tube—one branch led to a wired-up moth and the other to a machine that identified and recorded the individual chemicals as they breezed by. Speakers attached to this gizmo emitted a rapid pop-pop-pop-pop sound if the moth was turned on by a chemical. Turns out the moth brains “popped” to only nine chemicals from sacred datura’s complex bouquet.

The scientists proceeded to study how 420 moths behaved toward the chemicals by putting a moth at one end of a wind tunnel and an artificial flower made of white filter paper doused with datura odors at the other. The insects were not impressed by the chemicals if they were presented one at a time. But when all nine chemicals that had made the moth brains “pop” were put on a paper flower, they stuck out their tongues to imbibe nectar, just as they would when faced with a real sacred datura flower.

Lead researcher Jeffrey A. Riffell’s first-hand account of the experiment is in today’s Science Daily. The paper, “Characterizing and Coding of Behaviorally Significant Odor Mixtures,” is in the current issue of the journal Current Biology. The title alone makes a persuasive case for the value of science journalism.

Evolutionary Biology Over Animatronic Religious Mythology?

Tuesday, December 2nd, 2008

A web campaign has scuttled a joint promotional deal launched last week by the Cincinnati Zoo and Botanical Garden and the Creation Museum, which promotes a strict interpretation of the biblical version of how life began.