Mexican Cave Scorpions
Updated: 2010-03-19 16:50:50
Blind scorpions that live in the stygian depths of caves are throwing light on a long-held assumption, showing that specialized adaptations aren't always an evolutionary dead-end. Looking at the phylogenetic relationships among species of the scorpion family Typhlochactidae, endemic to Mexico, Associate Curator Lorenzo Prendini and his colleagues observed that species currently living closer to the surface (under stones and in leaf litter) evolved independently on more than one occasion from specialized deep-cave ancestors adapted to life further below the surface (in caves). This finding puts a dent in both Cope's Law of the unspecialized, which assumes that novel evolutionary traits tend to originate from a generalized member of an ancestral taxon, and Dollo's Law of evolutionary irreversibility, which theorizes that specialized evolutionary traits are unlikely to reverse........