Applying analyses designed by City College of New York biologist Mike Hickerson, a team of international researchers is challenging a commonly held view that explains how so many species of birds ended up in the Neotropics, an area rich in rain forest extending from Mexico to the southernmost tip of South America. It is home to the most bird species on Earth.
"The unanswered question has been—how did this extraordinary bird diversity originate?" said Dr. Brian Smith, lead author of a paper on the subject published in the journal Nature this week and an assistant curator at the American Museum of Natural History.
According to traditional thought, this is the result of geological and climate changes over time. When rivers change course, mountains rise, and continents drift, a once-continuous population can be divided into two or more smaller populations that eventually become different species.
However, based on computational analyses and modeling designed and implemented by Dr. Mike Hickerson, associate professor in The City College biology department and The Graduate Center, CUNY, that may not have been the case.
The scientists compared genetic patterns among a diverse array of bird lineages that occur in the Neotropics and came up with an alternative theory. The evidence pointed at speciation driven by movements of birds across physical barriers such as mountains and rivers that occurred long after those landscapes' geological origins.
Other institutions involved in the research included Museu Paraense Emílio Goeldi (Brazil), Universidad de los Andes (Colombia), Universidad Central de Venezuela, Colección Ornitológica Phelps (Venezuela), UCLA-Los Angeles and the University of Georgia, in Athens.