To understand the genetic basis of these trait differences, the researchers conducted several genomic analyses on exomic DNA, the regions of the genome that code for proteins. They identified a set of 33 genes found in three regions of the lizard genome that were repeatedly associated with urbanization across populations, including genes related to immune function and metabolism.
“While we need further analysis of these genes to really know what this finding means, we do have evidence that urban lizards get injured more and have more parasites, so changes to immune function and wound healing would make sense. Similarly, urban anoles eat human food, so it is possible that they could be experiencing changes to their metabolism,” said Winchell.
In an additional analysis, they found 93 genes in the urban lizards that are important for limb and skin development, offering a genomic explanation for the increases in their legs and toe pads.
“The physical differences we see in the urban lizards appear to be mirrored at the genomic level,” said Winchell. “If urban populations are evolving with parallel physical and genomic changes, we may even be able to predict how populations will respond to urbanization just by looking at genetic markers.”
“Understanding how animals adapt to urban environments can help us focus our conservation efforts on the species that need it the most, and even build urban environments in ways that maintain all species,” added Winchell.
Do the differences in urban lizards apply to people living in cities? Not necessarily, according to Winchell, as humans aren’t at the whim of predators like lizards are. But humans are subject to some of the same urban factors, including pollution and higher temperatures, that seem to be contributing to adaptation in other species.
Additional study authors include Shane Campbell-Staton of Princeton University, Jonathan Losos of Washington University in St. Louis, Liam Revell of the University of Massachusetts Boston and Universidad Católica de la Santísima Concepción in Chile, Brian Verrelli of Virginia Commonwealth University, and Anthony Geneva of Rutgers University-Camden. The research was funded in part by the National Science Foundation (DEB 1354044, DEB 1927194, DEB 1701706), and by the University of Massachusetts Boston Bollinger Memorial Research Grant.
