In this situation, any variant in male anatomy or behavior that makes its bearer a better guarder is likely to be passed on to all the extra offspring he fathers, allowing guarding behaviors to evolve and spread in the population via sexual selection.This monopolizing strategy is particularly successful and particularly likely to evolve when a mate-and-run strategy can't assure 100% paternity and when females are relatively scarce.What they found out about the social life of the Indonesian octopus Abdopus aculeatus is the stuff of daytime television: jealousy, brawls, betrayal, sneaking around behind one another's backs if they had backs, that is and, a soap-opera favorite, the open-ended question of paternity.
Long assumed to be loners, at least one octopus is now known to lead a complex love life.
Last month, biologists Christine Huffard, Roy Caldwell, and Farnis Boneka reported on one of the first long term studies of octopus mating behavior in the wild.
The sneaking male hides behind a rock, extends his mating arm to the female, and, if lucky, accomplishes his mission. Don't worry about me I'm just a female octopus passing through") can work a bit too well: the researchers saw a guarding male set his sights on the sneaker male octopus passing though his territory and try to mate with "her." Why would a male change his stripes (literally), sneak around, and risk the unwelcome amorous advances of another male? All this guarding, aggression, repeat mating, and sneaking can be traced to one factor: paternity who gets more genes into the next generation.
Sexual selection favors any gene, anatomical structure, or behavior no matter how bizarre that provides a reproductive advantage.
And animals have evolved some doozies when it comes to sneaky mating behavior: Small dung beetles play the milkman calling at the back door.
They excavate a side entrance into the tunnel system guarded by a larger dominant beetle, mate with the female chambered there, and try to slip away undetected.The smallest males of one marine isopod species make up for their small size with heavy investment in sperm.These little crustaceans sneak into the sponge commandeered as a love nest by a larger male and then dive bomb the mating couple, releasing a cloud of sperm at the critical moment.A behavioral or physical variation (e.g., female impersonation, hit-and-run mating) that lets them father even a few offspring gives a big payoff in terms of genes in the next generation.And if those offspring also employ the non-traditional mating strategy and themselves manage to father a few offspring, the new mating strategy may become a permanent part of the population's behavioral repertoire.It might arise through a series of mutations that cause their bearer to employ the alternative strategy or that allow their bearer to switch back and forth between mating strategies depending on the situation.