It goes without saying that some people choose to have children too early in their lives. Apparently, teen pregnancy rates are particularly high in the United States. This should not come as a surprise considering that MTV airs a show that is entirely centered around struggling teen parents. Obviously, this particular social issue does not apply to the animal world. Gorillas, bears, arthropods or any other animal can reproduce at any sexually mature age without having to worry about finding a reliable daycare so that their parents can finish college. However, there is one particular insect species that may be pushing it a little by becoming pregnant while enclosed within an egg inside of their mother’s belly.
Most aphid species are born pregnant and only produce females. This is due to a modified system of meiosis that skips the reduction division, thus maintaining diploidy and heterozygosity. Males can also be produced through asexual meiosis due to a mechanism that discards the X chromosome. Aphids can also reproduce sexually in addition to asexually in order to produce a more genetically varied population that is more resilient to disease and other harmful environmental threats. Aphids choose to revert to sexual reproduction when a threat to their existence becomes noticed, such as harsh weather. A more genetically diverse aphid population can better withstand environmental catastrophes than a genetically identical population.
While the particular form of asexual reproduction demonstrated by aphids is incredibly rare in other organisms, some insects spend a majority of their lives as larvae and a very short time as adults. For example, the Cecropia moths of North America spend two months as larvae before spending less than ten days as adults. As larvae, these moths feed constantly in relative safety from predators, but during their short time as adults, they are unable to eat anything, as their digestive system is not developed enough to process food; instead, these moths spend their short adult lives struggling to find a mate for passing on their genes.
Do you know of any other insect species that reproduces asexually?