Sept. 28, 2018 (Phys.org) -- Beetles neglected by their parents evolve bigger mandibles, a new study shows.
Scientists at the Cambridge Zoology Department exposed hundreds of beetles to two levels of parental care for 13 generations. In a No Care environment, parents were removed as soon as they had prepared their mouse carcass nest but before their larvae had hatched. By contrast, in the Control environment, the parents were allowed to care for their young until they were ready to leave home.
The researchers found that when parents fed meat to their babies' mouth-to-mouth, the larvae evolved relatively smaller mandibles. These horizontally-aligned bladelike jaws play a vital role in the larva's life, enabling them to enter the carcass and feed on the flesh once inside, but they are less important when parents help their young to feed.
"By contrast, when the parents were removed from their young and larvae were forced to self-feed, the larvae evolved significantly larger jaws to compensate for the lack of help", said Benjamin Jarrett, who led the study."
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