Bizarre insect inbreeding signals an end to males
A bizarre form of inbreeding could spell the end of males in one insect species, according to researchers from Oxford University. The research focused on cottony cushion scales, a hermaphroditic bug species in which females appear to fertilize their own eggs. "It turns out that females are not really fertilizing their eggs themselves, but instead are having this done by a parasitic tissue that infects them at birth," said Laura Ross, one of the study's authors. "It seems that this infectious tissue derives from leftover sperm from their fathers." In effect, the tissue enables males to father offspring with both their mates and then their daughters. According to a mathematical model developed by Ross and her co-author Andy Gardner, this odd reproductive tactic could eliminate the need for males in the species. Once the parasitic fathers become widespread in a population, females will be inclined to reproduce with them instead of regular males. Regular males, as a result, become very rare because they have a hard time finding willing mates.
Andy Gardner and Laura Ross, "The Evolution of Hermaphroditism by an Infectious Male-Derived Cell Lineage: An Inclusive-Fitness Analysis."
Without competition, island frogs evolve rapidly
Scientists led by Ben Evans of McMaster University have documented the rapid evolution of new fanged frog species on the island of Sulawesi, near the Philippines. The team found 13 species of fanged frog on the island, nine of which hadn't previously been described. The species differ in body size, amount of webbing in their feet, and even how they raise their youngall in accordance with the demands of their distinct ecological niches. Sulawesi has the same number of fanged frog species as the Philippine archipelago. "We would expect to find more species on the archipelago because it's so much larger, but that's not the case," Ev
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