Evolution of Hummingbird Traced Across the World
The evolutionary history of the tiny humming bird has been reexamined in a new family tree constructed from DNA samples of hundreds of individual birds.
Writing in the journal Current Biology, a team of evolutionary experts documented the hummingbird's origins in Europe and the bird's migration through Asia and North America before finding its paradise in South America about 22 million years ago, where it evolved rapidly into the various groups known today.
"Our study provides a much clearer picture regarding how and when hummingbirds came to be distributed where they are today," lead author Jimmy McGuire, a UC Berkeley associate professor of integrative biology, said in a statement.
McGuire conducted the research along with experts from UC Berkeley, Louisiana State University and the universities of New Mexico, Michigan and British Columbia.
The researchers report that there are now 338 recognized hummingbird species, but that number could double over the next 7 million years.
"We are not close to being at the maximum number of hummingbird species," McGuire said. "If humans weren't around, they would just continue on their merry way, evolving new species over time."
The study is the result of more than 12 years of research processing DNA samples from 451 specimens of 284 species of hummingbird, chronicling their migration and ultimate proliferation in South America.
McGuire, a herpetologist by training who is interested in the evolution of reptile and amphibian diversity, said he wants to better understand how hummingbirds took root in South America, considering they are dependent on plants that coevolved with them.
"It is really difficult to imagine how it started, since hummingbirds are involved in this coevolutionary process with plants that has led to specializations we typically associate with hummingbird plants, such as tubular, often red flowers, with dilute nectar," he said. "They drive the evolution of their own ecosystem. The evolution of hummingbirds has profoundly affected the evolution of the New World flora via codiversification."