CEB Committe on Evolutionary Biology

Of birds and bivalves: Similarities in species diversity and range across latitudes

David Jablonski, PhD, is the William R. Kenan Jr. Distinguished Service Professor in Geophysical Sciences at UChicago. Trevor Price, PhD, is a professor in the Department of Ecology and Evolution. Both are faculty of CEB. 

This article was recently published on the University of Chicago's ScienceNews. An excerpt is below. Please click here to read the full article. 

Marine and terrestrial species inhabit vastly different ecosystems, but they share one of the primary patterns of biodiversity on the planet. The numbers of species of both groups increase toward the equator, with fewer species in temperate, higher latitudes and more in the tropics.

An unusual new study led by researchers from the University of Chicago shows that while terrestrial birds and marine bivalves—animals such as scallops, mussels, cockles, and oysters—share this pattern of species richness across latitudes as well, they arrive there quite differently.

Birds have a large number of species that inhabit only a narrow band of latitude within the tropics, and more broad-ranging species in temperate regions. Bivalves, however, have their broadest-ranging species in the tropics. Despite this difference, in both groups the more diverse evolutionary lineages—the ones containing more species—had the best chance of producing a individuals that could cross the tropical-temperate boundary that serves as a strong barrier for many species.

The study, published May 4, 2016, in the Proceedings of the Royal Society B, is one of the first of its kind to compare such disparate marine and terrestrial ecosystems, and shows that evolutionary and biogeographic dynamics appear to be closely tied.

“It’s extremely unusual to study a really big diversity pattern in both a marine and terrestrial group using exactly the same methods,” said paleontologist David Jablonski, PhD, the William R. Kenan Jr. Distinguished Service Professor in Geophysical Sciences at UChicago. “This comparison seemed a good way to get at truly general rules of how biodiversity works.”

The study was a collaborative effort between Jablonski, who studies large-scale patterns of evolution in marine life, and biologist Trevor Price, PhD, a professor in the Department of Ecology and Evolution who studies speciation and spatial patterns in birds.

Please click here to read the full article.