A recent study explores how urban life may influence the evolution of city-dwelling coyotes, a resilient species that can be seen in places like Berkeley, California, and the Bronx, New York.
A recent study explores how urban life may influence the evolution of city-dwelling coyotes, a resilient species that can be seen in places like Berkeley, California, and the Bronx, New York.
Traditionally, evolution was believed to occur over lengthy periods. However, scientists have come to realize that evolution can occur in just a few generations. Urban environments provide a unique perspective on how evolution takes place over shorter timescales and how species adapt to human activities and new surroundings.
Certain species, particularly coyotes, appear to be well-equipped for coexistence with humans.
“Coyotes are thriving in urban areas,” noted Elizabeth Carlen, a postdoctoral fellow at the Living Earth Collaborative at Washington University in St. Louis and the lead author of a study published in Genome Biology and Evolution.
“Considering the close evolutionary ties between coyotes and domestic dogs, we utilized the dog genome to identify which genes might be under selection in urban settings and how they may be evolving,” Carlen stated.
“For coyotes specifically, we have well-documented the ecological variations between urban and rural populations,” stated Samantha Kreling, a PhD candidate at the University of Washington and the primary author of the study. “Nonetheless, despite acknowledging the existence of genetic and ecological differences, limited research has investigated the specific genes or genomic regions that could be influenced. Our research presents potential candidate genes for examining adaptive evolution in urban coyotes.”
This candidate gene approach involves selecting specific genes of interest for sequencing and analysis. While sequencing the entire genome or epigenome is the ideal approach for understanding evolutionary changes and adaptations, these techniques can be prohibitively expensive—especially for wildlife-focused studies, as explained by Carlen.
For research with constrained budgets, focusing on particular candidate genes for sequencing allows researchers to test hypotheses while keeping sample sizes large enough for statistical significance. The study by Carlen and Kreling highlights life history traits that might be evolving in urban coyotes and lists candidate genes that could be relevant, including those connected to diet, health, thermoregulation, behavior, cognition, and reproduction.
For instance, consider the genes related to the coyote’s dietary habits.
While rural coyotes primarily consume rabbits, mice, and other small animals, urban coyotes often have access to pet food left outside and human trash. This likely results in increased intake of glucose and starches, according to Carlen from WashU.
If excessive sugar consumption leads to insulin resistance and negative health effects, then genes that regulate insulin sensitivity and production may be favored in urban environments. Similarly, urban coyotes are likely evolving to digest more starch, similar to findings in domestic dogs, who have multiple copies of the AMY2B gene responsible for producing amylase and enhancing starch digestion.
Living with Humans
Coyotes are increasingly prevalent in urban regions across the United States, although local population trends differ. “We know that the East Coast is seeing a rise in coyote numbers due to the displacement of wolves,” Carlen explained.
“In these areas, more coyotes are appearing because they are filling ecological roles that were previously held by wolves,” she added. “If a wolf were to wander into the Bronx, it would likely be killed, but coyotes can adapt to these urban settings.”
In St. Louis, another initiative backed by the Living Earth Collaborative, called the Forest Park Living Lab, employs motion-triggered cameras and GPS collars to monitor coyotes in and around Forest Park, near WashU.
In 2024, local residents accompanied by a journalist and photographer from the St. Louis Post-Dispatch documented the scientists’ attempts to trap and track a visiting male coyote and a mother coyote with pups. Although tracking aimed to extend over a year, both adult coyotes unfortunately passed away shortly after their release.
Studying urban coyotes presents both intriguing opportunities and challenges, said Carlen, who has collaborated on local coyote research with partners like the Saint Louis Zoo. The animals are intelligent and tend to avoid human interaction.
“There’s a lot of unwarranted fear surrounding coyotes,” she remarked. “They are quite sizable creatures sharing our urban environments, yet I believe they face undue persecution.”
She hopes this research will provide guidance for scientists studying urban adaptations in coyotes and inspire other urban evolutionary biologists to compile their candidate gene catalogs for various species.
“Although we have seen growth in urban evolution research, the connection between specific genes and adaptations in urban contexts remains largely uncharted,” Carlen concluded.
