Cities and Artificial Lights Are Driving Evolution in a Surprising Way

Cities and Artificial Lights Are Driving Evolution in a Surprising Way

The 19th century was the age of machine tools and urbanization. The invention of the electric bulb has changed the world. Today, our world is filled with powered devices, such as smartphones which can be used to play mobile casino games. More than half of the world’s population now live in cities and the number is expected to rise over 70% by 2050.

Species Adapting to Urban Environments

The pollution in urban areas boosts the mutation rate in many species. A recent study in Hamilton found this effect in mice and gulls near the steel plants in the city. Some species like house finches are adapting to the environment in cities via natural selection. Big structures like highways and bridges are isolating the population of species like the red-black salamanders of Mont-Royal in Montreal. Such species are becoming genetically different overtime from the others in nearby areas.

As the process of urbanization continues, some animal species will disappear from the urbanized areas. For instance, birds that feed on a specific food will fly to other areas in search of food. Species that cannot keep up with the rapid pace of urbanization will disappear in the future. On the contrary, species such as crows and doves will move into the city. This means that urbanization will filter the bird communities in the coming years.

Effect of Artificial Light on Different Species

A second agent of evolutionary change is the innovation of electric light. The spread of electricity across many parts around the world has condemned darkness to the earth’s history. Plants and animals depend on the earth’s daily cycle of light and dark rhythm to govern life-sustaining behaviours such as sleep, nourishment and so on. Researchers have found that artificial light at night has negative effects on many creatures including birds, mammals and insects.

Nocturnal animals are active at night. Artificial lights alter their nighttime environment by converting night into day. “The introduction of artificial light represents the most drastic change that humans have made to the environment,” says research scientist Christopher Kyba. “Predators use light to hunt at night and prey species use darkness as a cover. In urban areas, cloudy skies are now thousands of times brighter than they were in the last century. This is only the beginning of the effects that artificial light will have on the ecology.”

Birds that migrate use moonlight and starlight to navigate in the dark. Light can cause them to wander off course towards the dangerous nighttime landscapes of urban areas. Millions of birds die colliding with needlessly illuminated buildings and towers every year. Although migratory birds depend on cues from properly timed schedules, lights can cause them to migrate too early or too late.

Night-shift Workers

In developed countries, over 20% of the workforce is employed in service industries that require employees to be awake at night. Night shift workers such as health care attendants are some of the people who bear this burden. These people seldom replace the number of hours of sleep they missed at night with the same number of hours of sleep during the day.