A study analyzing 1,600 cases around the world determined that plants and animals are adapting their phenotypes for the urban environment, changes that could affect the ecosystems and human well-being.
Phenotypes are the physical manifestation of genes. If you have genes that produce green eyes, your eye color is the phenotype. The researchers found that certain species phenotypes are seemingly affected by their living in urban environments. These changes included different body size, reproduction habits, and changes in behavior.
“We found that there is a clear urban signal of phenotypic change, and also greater phenotypic change in urbanizing systems compared to natural or non-urban anthropogenic systems,” said study co-author Marina Alberti of the University of Washington’s Department of Urban Design and Planning told the BBC. “So urbanization, globally, is clearly affecting things.” This isn’t an entirely surprising finding, as urbanization has increased dramatically in the last few hundred years. More than half of the human population on Earth now lives in cities.
“The reason these changes are important is because they change ecosystem function, therefore they have implications for human well-being,” Alberti told BBC. “This is because those changes affect, for example, biodiversity but also nutrient cycling, seed dispersal and water purification.”
This study also provides evidence that we are entering the so-called , a period of geological time where humans will significantly impact life on earth.
“There have been a lot of studies on individual cities but there had been no studies that considered the global picture to identify a global urbanization influence on evolution,” Alberti said. “We live on an urban planet already. This is a change that has implications for where we are heading in the future.
Image credit: Lori Fortini
This article was originally written for and published by Popular Mechanics USA.