The London Underground may have its own distinct subspecies of mosquito, at least that's the theory that has been suggested in the journal Heredity.
The Tube-dwelling bug seems to have developed separately to those living above ground due to the small but distinct barrier between each group.
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If verified, the evolution of the underground mosquito would qualify as an example of quick moving speciation, similar to Charles Darwin's famous finches on the Galapagos Islands.
Although the subspecies is believed to be so different that it's now unable to reproduce with other mosquitoes, not everyone in the science community buys the idea.
This is because the mosquito has been found in various underground situations, including an outbreak in the sewers of New York City in 2011.
According to National Geographic mosquitoes can live for anywhere between two weeks and six months in the wild.
There are currently more than 3,000 species of mosquito in the world, some of which carry deadly parasites that lead to millions of deaths each year.
In other cases, such as yellow fever and dengue fever, a virus carried by the mosquito infects humans through the mosquito's saliva.