Letters from the August 12, 2006, issue of Science News

August 4, 2006 at 6:15 pm

Dates of contention

Are the dates quoted in “Stones of Contention: Tiny Homo species tied to ancient tool tradition” (SN: 6/3/06, p. 341) correct? I didn’t think Homo existed as a genus 840,000 years ago.

David Adams
Boothwyn, Pa.

Fossil finds indicate that the Homo genus originated roughly 2.4 million years ago.—B. Bower

No juicy story

“Homegrown Defender: Urinary infections face natural guard” (SN: 6/10/06, p. 355) leads me to ask if this explains the efficacy of that standard home remedy for preventing urinary tract infections: cranberry juice. Does it contain a cathelicidin mimic or some irritant that (benignly) stimulates cathelicidin secretions?

Gregory Honchul
West Liberty, Ky.

There is evidence that the juice can thwart bladder infections, but the mechanism appears to be in preventing bacteria from binding to cells lining the urinary tract. The microbes then get flushed out. In contrast, the body’s homemade cathelicidins puncture a bacterium’s membrane and kill it, a more direct approach.—N. Seppa

Divide and conquer

Reading the June 10 issue, I was prepared to catch the Simpsonesque spoof (blunder?) in the “Leggiest Animal: Champ millipede located after 79-year gap” (SN: 6/10/06, p. 357). Perhaps the creature had up to 748 legs, or possibly up to 752 legs, but not “up to 750 legs.”

David Clark
Lititz, Pa.

Researcher Paul Marek of East Carolina University explains that Illacme plenipes has four legs per segment, except for segments 2, 3, and 4, which have one pair each, and three segments that don’t have any legs. So, an individual with 192 segments would have 750 legs.—S. Milius

Disorder in the court

With the known link of asbestos to lung cancer, the new finding that many other diseases can be caused by asbestos only serves as fodder for litigation, clogging of our legal system, and, unfortunately, more enrichment of trial lawyers instead of asbestos victims (“Mineral Deposit: Asbestos linked to lupus, arthritis,” SN: 6/17/06, p. 372).

Nelson Marans
Silver Spring, Md.