Rapid Urban Evolution
In schools, we are taught that evolution is an imperceptibly slow process, the long and drawn-out ascent from fish to reptiles, reptiles to birds and mammals, mammals to humans. But it turns out, when you take the time to look closely, evolution is taking place all around us, fast enough for us to see and measure. What’s more, evolution may even happen faster around us since we humans tend to create novel and often extreme selection environments that encroaches into natural habitats (or for those that hitchhike with us). Johnson and Munshi-South (2017) reviewed the growing list of studies uncovering rapid evolution of wildlife in response to urbanization. When faced with new environmental challenges, populations of organisms are presented with two options: move or adapt. (The third, extreme alternative is extinction). Urban wildlife populations are either residual populations that existed prior to urban development or new populations that colonized after a city emerged. It’s clear that almost anywhere you look in cities, wildlife is evolving in response to our presence. This bestows us with a massive responsibility and indebts us to an ethic of conservation to preserve as much unencumbered wild habitat as possible and work on mitigating the effects of our urban infrastructure.