Am I breeding a master race of mosquitoes?
Sarah asks, 'I live in an area with a huge number of mosquitoes. By swatting the weakest ones, am I creating a master race?'
James Tytko took on this question with the help of Laurence Hurst from the University of Bath...
James - A thought to make your skin crawl. But could whittling away the measliest mosquitos be having an effect on the population? To help us find the answer, I got in touch with Laurence Hurst, Professor of evolutionary biology at the University of Bath.)
Laurence - Thanks James. In short, the answer to Sarah’s question is no: the notion that swatting a few mosquitoes will result in a master race of mosquitoes is not a problem I would worry about.
It is known that broad scale measures in which a sizeable proportion of a population are affected can cause rapid evolution. For example hunting for prized specimens of several species with large tusks or horns has led to selection favouring shorter horns or tusks.
Likewise, broadscale administration of insecticides has led to the evolution of insecticide resistance (including in mosquitoes).
The difference between these situations and the mosquito whacking by Sarah is the scale of the enterprise, meaning the proportion of the population affected.
James - So you’re right to deduce, Sarah, that swatting the weakest and least cunning mosquitos might mean the mutations associated with these characteristics are not inherited by as many future generations.
Laurence - However, the reason that this case is different from the others is that a minuscule proportion of the population is affected so the strength of selection operating on the average mosquito to be more cunning is itself miniscule. In a way, Sarah, you’ve answered your own question - if there are a huge number of mosquitoes where you live, the proportion that you’re likely to whack is tiny!