Sexton beetles, Nicrophorus vespilloides and larva Credit: tomhouslay.com |
How do you make your offspring grow big and strong?
If you are a sexton beetle, you feed them on dead mice, neglect them and let them fend for themselves. Well, not exactly their immediate offspring but the offspring of your 11 time great grandchildren who will evolve to be better at fending for themselves than those who are cared for, as this observed example of evolution in a laboratory shows.
Sexton beetles, Nicrophorus vespilloides, provide a useful service in the British countryside by burying the dead bodies of mice and other small vertebrates to create food for their offspring. They represent an intermediate level of parental care, between providing for all their needs and providing no care at all. Normally, the females remove the hair from the corpse and make cuts into the skin so their larvae can get into the body more easily. They will also bite off pieces of flesh and feed it to their larvae.