As cities grow, pests and insects evolve rapidly to adjust: Study

Researchers have found that urbanization has influenced the evolution of native species. This has helped the native species to adjust to the changing environments. However, it has also resulted in the evolution of disease-causing pest to become more resistant to pesticides. The healthcare has to evolve to deal with the situation.

FILE PHOTO: A view of the Empire State building and midtown Manhattan skyline of New York City at sunrise as seen from Hoboken, New Jersey, U.S. on August 9, 2017. Reuters

A recent study done by the researchers from the University of Toronto and the Fordham University found that urbanization has an impact on the mechanism of evolution.

The researchers found that organisms living in the urban habitats evolve to cope up with the changing environments. These evolutionary processes include genetic adaptations such as mutations, the movement of genes through dispersal, neutral evolution and adaptive evolution through Darwinian natural selection.

The loss of habitat and creation of urban barriers including roads and buildings would create challenges to all native species and force them to adapt to changes in different ways, said the study which was done on various levels of organisms including mammals, plants, birds, amphibians, reptiles, insects and viruses. All of them showed different kinds of evolutionary adaptation in their isolated localities.

The research found that the white-footed mice in New York had undergone changes which differed them in different pockets of the urban regions. Similarly, the mosquitoes in London underground had evolved to produce eggs without feeding on blood. They had also become active in winter times. These mosquitoes, however, have gained more ability to carry diseases across the New York City, Chicago, and Los Angeles.

Marc Johnson, of the University of Toronto Mississauga, said, "As we build cities, we have little understanding of how they are influencing organisms that live there. It's good news that some organisms are able to adapt, such as native species that have important ecological functions in the environment... But it can also be bad news that the ability of some of these organisms to adapt to our cities might increase the transmission of disease."

Bedbugs have evolved into a species which are unaffected by any strong insecticides posing new problem across the globe. So are other species like rats, urban lizards, cockroaches, and pigeons which have evolved with the changing conditions and started to depend more on humans for their survival.

The research had also studied the influence of this impact on the health of human beings. The researchers suggested that the city planning should consider native species and should "be kinder to ourselves and the environment." It should answer the challenges like conservation of native species while dealing with ways to avoid disease-carrying pests.