Early immigrants, earlier

The multiple-origin theory of ancient New World immigration reported in “Continental Survivors: Baja skulls shake up American ancestry” (SN: 9/6/03, p. 150: Continental Survivors: Baja skulls shake up American ancestry) has a long and respectable scholarly history, though it’s tarnished from time to time by enthusiasts for one race or another. For an early popular treatment, see Men out of Asia by Harold Sterling Gladwin (1947, McGraw-Hill). Gladwin even mentioned the Pericú, who were cited in the article.

Gene McWhorter
Longview, Texas

Link’s no lock

Multiple sclerosis (MS) is considered to be an autoimmune disease of the central nervous system that attacks the myelin sheath around neurons. If there were a relationship between myelin and psychiatric illnesses, as suggested in “DNA Tie for Two Disorders: Genetic defects link psychiatric ailments” (SN: 9/13/03, p. 164: DNA Tie for Two Disorders: Genetic defects link psychiatric ailments), then many people with MS would suffer from schizophrenia or bipolar illnesses. The study is much too small to make such sweeping claims.

Vic Arnold
Houston, Texas

Error bars get no respect

In your article on experimental hints of a new subatomic particle (“Particle decays hint at new matter,” SN: 9/20/03, p. 189: Particle decays hint at new matter), three values are quoted for a particular charge-parity violation, all with error bar. Given the large uncertainties in two of these, the three are undistinguishable. Yet you claim that they “don’t agree.” Does no one look at error bars any more?

R.A. Williams
Los Alamos, N.M.


What would sessile organisms do with information provided by the light from “their meals” (“Channeling light in the deep sea,” SN: 9/20/03, p. 190: Channeling light in the deep sea)? Just because spicules on a sea sponge transmit photons doesn’t mean that that’s their function.

David Contey
Boulder, Colo

Each Euplectella sponge houses a pair of bioluminescent shrimp. The researchers speculate that the spicules transmit the shrimps’ light into the sponge’s surroundings. The glow attracts organisms that the shrimp eat. In turn, the sponge feeds on waste products of the shrimp.–P. Weiss


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