With new technology to analyze the entire genome, combined with the Smith's years of ecological data and insights, they had all the pieces to find and understand the genes behind this mystery. That Mendelian pattern was the key, said vonHoldt. "Traits rarely show such a clean pattern of inheritance, especially traits that are very central to fitness in a wild population." "You never get this!" said vonHoldt with a laugh. The larger beak was the dominant trait, so two small-billed parents could only have small-billed offspring, but if either parent had a large bill, their offspring would have a mix of large and small bills, perfectly matching the 3:1 pattern predicted by Gregor Mendel centuries ago. The result was startlingly and elegantly simple: Mendelian genetics, best known to generations of high school students through Punnett squares. Smith, who is a professor at UCLA as well as the founding director of the Center for Tropical Research, established a breeding colony of these finches to understand the inheritance of beak size. Much of their original work identified differences in the hardness of the seeds they eat, a story quite similar to that of Darwin's finches. He and his colleagues have spent years investigating why some of these finches have small beaks while others have large beaks. The birder and biologist was Tom Smith, who has spent his career studying finches - specifically, black-bellied seedcrackers ( Pyrenestes ostrinus) - in Cameroon and in his lab at the University of California-Los Angeles. "I was presented with a new problem in an entirely new system, which was an incredible opportunity to explore how different ecologies could promote different evolutionary patterns." "I love a good challenge and especially working on new questions!" said vonHoldt, an assistant professor of ecology and evolutionary biology at Princeton. view moreīridgett vonHoldt is best known for her work with dogs and wolves, so she was surprised when a bird biologist pulled her aside and said, "I really think you can help me solve this problem." So she turned to a mystery he'd been wrestling with for more than 20 years. Image: Princeton biologist Bridgett vonHoldt discovered that the 'mega' morph of the black-bellied seedcrackers (Pyrenestes ostrinus), a Cameroonian finch, appears to result from an additional evolutionary step after the evolution of the large- and small-beaked morphs.
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