Scientists have known for decades that the "innate" song of an isolated songbird is different from the "learned" song of a songbird that was tutored by an adult. But where did that adult tutor's song come from? Obviously from it's own father, but where did this passed-down song originate? "This is a classic chicken-and-egg problem," says Mitra.
He hypothesized that if the song of an isolated songbird were transmitted over multiple generations, the normal wild-type song would somehow spontaneously emerge. Using what mathematicians call a "recursive equation," he came up with a mathematical model of how this might happen. This model, combining ideas from the literature on cultural evolution and quantitative genetics, tries to quantify the relative contributions of the songbird's genetic background, learning ability and environmental factors to the emergence of the cultured song.
Multigenerational progress towards song culture
To experimentally test his hypothesis, Mitra five years ago approached his long-time collaborator, Professor Ofer Tchernichovski, Ph.D., a songbird biologist at CCNY. Tchernichovski and his graduate student Olga Feher took up the experimental challenge, raising songbirds in soundproof boxes and collecting audio and video recordings of their subjects. Mitra and CSHL postdoctoral fellow Haibin Wang in turn analyzed these recordings, comprising a large dataset of several terabytes, which show that the innate song of an isolated bird is gradually transformed over multiple generations into a song that closely resembled the song normally found in the wild.
"I was more pleased than surprised with the experimental data," admits Mitra. "I came in with a strong bias that wild-type song culture would spontaneously emerge." His
|Contact: Hema Bashyam|
Cold Spring Harbor Laboratory