How does urbanization affect evolution


Over the last decade or so, our world has changed rapidly. Advancements in technology have boomed with our society becoming more and more like a sci-fi movie each day; virtual reality, hoverboards, self-driving cars, and robots are now actually real things. As our cities grow larger and our lives become more urbanized, what does it mean for evolution? A report by Marc T. J. Johnson and Jason Munshi-South for Science has delved into what urbanization is doing to evolution in our current times.

The London Underground mosquito

When the London Underground was built in the 19th Century, nobody expected it to become home to a rapidly evolving mosquito. This unique London Underground mosquito has been studied for its rather interesting rate of evolution. Katharine Byrne, a doctoral student from London, decided to collect mosquitoes from seven sites across the tube network to study what made them different from their surface-dwelling counterparts. It turns out, the results were quite shocking. This mosquito had evolved to not require blood to make eggs, to not need to hibernate during winter, and to stop interbreeding. Genetically, these mosquitoes have evolved unlike any other of their kind – and in such a short space of time.

The Tucson house finch

Another study conducted in the last decade, by Alexander V. Badyaev wanted to look at the evolution of the simple house finch. Was urbanization playing a part in the length of their beaks? Badyaev seemed to think so. He found that in Tucson, Arizona, the birds had evolved to have longer and wider beaks – simply so that they could access more of the goodies in birdfeeders that people have in their backyards. A change in people’s behavior and the urbanization of the world has changed a bird’s beak… But what else could it do?

The bedbug problem

In the report by Johnson and Munshi-South, they bring up a prime example of what the urbanization of the world is doing to evolution – bedbugs. Around two decades ago, bedbugs were pretty much scarce; we just didn’t see them anymore. There were products to keep them at bay, and that was that. However, they have recently exploded in numbers across the world recently, because they have adapted to the pesticides we use. Random mutations and natural selection is causing some critters, such as bedbugs, to adapt to things like pollutions, the use of pesticides, the changing landscape, and climate.

Evolution speeding up

The report found that, in general, the urbanizations of our planet was causing evolution to speed up. Organisms were having to adapt or die at a much quicker rate than they would in the past, which has meant that evolution is moving so much faster. There are, however, some instances in which genetic diversity could slow things down. The red foxes which have migrated to Zurich, Switzerland, are a prime example of animals which may be at a greater risk of urbanization and changes, due to less genetic diversity.

In conclusion, it seems as though the speed at which we’re urbanizing the planet has definitely had an impact on its ecosystem. While some organisms are doing everything they can to adapt to whatever we may throw at them (from pollution to pesticides), there are some lesser genetic diverse species which will not be able to keep up. Urbanization has sped up evolution, but when will it stop? Perhaps it’s time to consider the environment more as we continue to build bigger cities and modernize our planet.