Adorable, yet vicious

Be warned, some evolutionary rambling will follow! Meerkats are those cute little desert mammals that were made famous by the Lion King movies. Remember…the meerkat and the warthog were buddies. I don’t remember their names, though I do remember they sang Hakuna Matata (no worries for the rest of your days). Anyways, real life meerkats are really interesting creatures. They live in small social groups, and they cooperate together in various ways, e.g. adult group members will teach young meerkats how to capture scorpions by disabling the scorpion first and biting off its stinger. Cooperative behaviour has always been considered a challenge for evolutionary theory. After all, if your primary goal is pass on your genes, why spend time being altruistic? This problem has been considered by many biologists (including Darwin himself), and a variety of non-exclusive solutions (e.g. kin selection, reciprocal altruism, multilevel selection) have been proposed, tested, and supported to various degrees. So why are meerkats so nice to each other? First of all, there are usually altruistic towards close relatives (kin selection), and second the group’s continued existence seems to depend on cooperation (multilevel selection). That’s all fine and good, but it turns out that these critters have a darker side too (I’ve always enjoyed the more cruel and twisted aspects of nature, because it undermines many people’s preconceived ideas about how the world “should” be…probably why I’m fascinated with parasites). During the breeding season, pregnant meerkats will actively try to kill any other pups, so that their own pups will receive all of the benefits of the group child-rearing, i.e. more time can be spent on your kid when there are fewer babies to raise. Furthermore, when the dominant female gets pregnant, she will chase and harass other females so much that their stress levels prevent them from becoming pregnant. Seems like females aren’t so cooperative when it comes to deciding who’s gonna reproduce. Hakuna matata? Not when you’re a subordinate female keen on starting a family.

Dan