Letters from the December 22 & 29, 2007, issue of Science News

Amylase with your veggies

Your article (“Advantage: Starch,” SN: 9/15/07, p. 173) notes how groups of people may have different numbers of copies of the amylase gene. Is it correct then that individuals have varying numbers of the gene as well? If so, would this explain why some people don’t like meat and become vegetarians and others just need to eat meat?

Robert Krase
Springville, Calif.

The researchers found that among 50 Arizona college students, the number of copies of the amylase gene ranged from 2 to 15. As for whether this explains vegetarian leanings, researcher Nate Dominy says that because amylase quickly converts plant starch to sugar in the mouth, excess amylase may make eating vegetables “a more rewarding experience.”—B. Vastag

Proof’s absence

Sid Perkins’ article on long-missing species (“Back from the Dead?” SN: 11/17/07, p. 312) validates a long-held principle of logic, namely, that one cannot prove a negative. It reminds me of an oft-cited legal warning: “Absence of proof does not constitute proof of absence.”

Mark Mailloux
Fenton, Mich.

Antiscience attitudes

In all the recent discussions regarding science education in the U.S. (“Showdown at Sex Gap,” SN: 11/24/07, p. 328), one factor that has not been mentioned is the antiscience attitude of many leaders and people in the media. It is fashionable to be ignorant of math, but not to be illiterate. This must have some effect on motivation to learn about science.

Dennis Brown
Portland, Ore.