Scientists have unlocked the genetic basis underlying the remarkable variation in body size observed in song sparrows, one of North America’s most familiar and beloved songbirds. This discovery also provides insights into this species’ capacity to adapt to the challenges of climate change.
The study, published today in Nature Communications, used genomic sequencing to successfully pinpoint eight genetic variants, or DNA mutations, largely responsible for the nearly threefold difference in body size observed across the song sparrow range from Mexico to Alaska. For instance, song sparrows that live year-round in the Aleutian Islands can be up to three times larger than their counterparts in the coastal marshes of California.
Katherine Carbeck, the study’s first author and a PhD candidate in the faculty of forestry, University of British Columbia, explains that body size varies predictably in many species that inhabit vastly different climatic conditions, aligning with “Bergmann’s rule” which states that organisms in cooler climates tend to be larger as an adaptation to regulate body temperature.
Read more at: University of British Columbia
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