By Will Bugler
Diseases including malaria, yellow fever, zika virus and dengue fever could return to Europe, according to the largest ever study of the mosquito evolutionary tree. The study investigates mosquito evolution over the last 195 million years and suggests that climate change today could provide favourable conditions for mosquito-borne diseases to spread in areas where they had been previously eradicated.
The research from the Milner Centre for Evolution at the University of Bath, University of York and China Agricultural University, shows that the rate at which new species of mosquitos evolve generally increases when levels of atmospheric carbon dioxide are higher. This is a concern because the greater the number of mosquito species, the more potential exists for new ways of transmitting disease, and perhaps for new variants of those diseases.
“It is important to look at the evolution of the mosquito against climate change because mosquitoes are responsive to CO2 levels” explained Dr Katie Davis, from the University of York’s Department of Biology, “Atmospheric CO2 levels are currently rising due to changes in the environment that are connected to human activity, so what does this mean for the mosquito and human health?
“Despite some uncertainties, we can now show that mosquito species are able to evolve and adapt to climate change in high numbers. With increased speciation, however, comes the added risk of disease increase and the return of certain diseases in countries that had eradicated them or never experienced them before.”
Chufei Tang, formerly at the Milner Centre for Evolution and now at the China Agricultural University, said “The rising atmospheric CO2 has been proven to influence various kinds of organisms, but this is the first time such impact has been found on insects.”
More research is needed to understand what climate change means for the future of the mosquito and the work will contribute to further discussions about the value of the mosquito to the ecosystem and how to manage the diseases they carry.
Tang et al (2018) “Elevated atmospheric CO2 promoted speciation in mosquitoes (Diptera, Culicidae)” is published in Communications Biology, DOI: 10.1038/s42003-018-0191-7. Click here to access the study.