Findings in title quoted from the linked summary^1 and its hyperlinked article^2 in PNAS.

From the linked summary:^1

>In the PNAS study, the researchers looked at 96 Anolis cristatellus lizards from three regions of Puerto Rico—San Juan, Arecibo, and Mayagüez—comparing lizards living in urban centers with those living in forests surrounding each city.

>They first confirmed that the lizard populations in the three regions were genetically distinct from one another, so any similarities they found among lizards across the three cities could be attributed to urbanization.

>They then measured their toe pads and legs and found that urban lizards had significantly longer limbs and larger toe pads with more specialized scales on their toes, supporting their earlier research that these traits have evolved to enable urban lizards to thrive in cities.

>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.

> 

>“Urbanization impacts roughly two-thirds of the Earth and is expected to continue to intensify, so it’s important to understand how organisms might be adapting to changing environments,” said Kristin Winchell, assistant professor of biology at NYU and the study’s first author.

>“In many ways, cities provide us with natural laboratories for studying adaptive change, as we can compare urban populations with their non-urban counterparts to see how they respond to similar stressors and pressures over short periods of time.”

^1 Urban Lizards Share Genomic Markers Not Found in Forest-Dwellers, 9 Jan. 2023, New York University.

^2 Winchell K., et al. Genome-wide parallelism underlies contemporary adaptation in urban lizards. Proceedings of the National Academy of Sciences, 2023. 120 (3) e2216789120. doi.org/10.1073/pnas.2216789120

ETA at 04:01 UTC: https://doi.org/10.1073/pnas.2216789120