The Study
In a study published on Thursday, researchers report that these birds have evolved to have longer bills in the UK. This has happened over a series of decades. We know that the birds with a longer bill will have easier access to the common bird feeder found in many British backyards. The data has proved that the longer beaked birds have had healthier offspring, and they produced more chicks that fledged.
The researchers discovered this example natural selection by studying the birds DNA. Both Britain and the Netherlands are home to great tit populations that have been studied for many years. The team conducting the study has suspected that the birds’ genes might hold clues into whether they’ve evolved differently.
Lewis Spurgin
Lewis Spurgin an evolutionary biologist at the University of East Anglia. “What we wanted to do in the great tits was say, ‘Can we see signatures of natural selection in the DNA and then can we relate that to actual individual-level differences?’” he said. Although the whole idea of natural selection started with variations in the beaks of Charles Darwin’s finches, Spurgin says the team “really didn’t expect it would be at all about beaks.”
After sifting through the genomes of nearly 3,000 birds, the researchers spotted some distinctive patterns. The related genes in humans, they discovered, control face shape. What’s more, the areas where differences popped up were associated with beak shape in Darwin’s famed finches.
“So we’re thinking, ‘Well, this looks like a beak thing here,’” Spurgin said. “What that told us was that the same bits of DNA that control beak length are actually under natural selection.”
