Europe's spookily pale and blind cave salamanders, called olms, include a dark form with what look like functional eyes, Susan Milius reported in "What's odd about a dark, big-eyed salamander" (SN: 4/30/16, p. 4).
Online reader John Turner wondered why dark olms evolved those traits. "Maybe every few generations, every few tries, a pigmented and sighted salamander makes it across open ground from one cave system to another cave system to spread the species," he wrote. "That would be the reward for keeping a few black sheep in the family, no?"
The evolution of dark skin and vision likely resulted from olms spending more time in shallow caves where it's lighter, says olm researcher Stanley Sessions of Hartwick College in Oneonta, N.Y. Their evolution, of course, "does not have a 'purpose' such as allowing [olms] to migrate over the surface," he says. Although spring floods occasionally wash both dark and light olms aboveground, "they are all thoroughly aquatic with delicate gills, and die very quickly if they are exposed to air for long," he says.
|Printer friendly Cite/link Email Feedback|
|Article Type:||Brief article|
|Date:||Jun 25, 2016|
|Previous Article:||Great Plains shake-up.|
|Next Article:||Plotting a course around Jupiter.|