Sex Against Parasites

A new study in American Naturalist suggest that sex may have evolved primarily as a defense against parasites. One theory is that parasites keep asexual organisms from getting too abundant. The reason being because when asexual organisms reproduce they create clones of themselves and each clone has the same genes. Each of the clones have the same genetic vulnerabilities towards parasites. On the other hand, sexual offspring are genetically different so a parasite that can destroy some can't necessarily destroy all. To carry out the study researchers Jukka Jokela, of Swiss Federal Institute of Aquatic Science and Technology, Mark Dybdahl, of the University of Washington, and Curtis Lively of Indian University, began by observing some snails called Potamopyrgus antipodarum from New Zealand. These snails are both sexual and asexual organisms so it gave the biologists a chance to compare the two versions side by side. The researchers found that while clones were plentiful at the beginning of the study but became more at risk to parasites over time. As the parasites increased the plentiful clones decreased noticeably in number. Meanwhile the sexual snail populations remained stable overtime. This proved the hypothesis.

This article relates to science and or biology because it talks about sexual reproduction. It discusses how sex might have evolved as a protection against parasites. This is interesting because not many people including myself would think that sexual reproduction or sex is actually a protection against anything. Sexual reproduction is apparently more efficient than asexual reproduction.

This article is significant because it is about a new finding in biology that can help in studies about asexual and sexual reproduction. Also it is good to know that something normal for the human race and all the other organisms that reproduce sexually can be a defense for parasites.




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