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http://www.lsu.edu/ur/ocur/lsunews/MediaCenter/News/2015/06/item76541.html
Until recently, most geologists had determined the land connecting North and South America, the Isthmus of Panama, had formed 3.5 million years ago.
But new data shows that this geological event, which dramatically changed the world, occurred much earlier. In a comprehensive biological study, researchers have confirmed this new information by showing that plants and animals had been migrating between the continents nearly 30 million years earlier.
This means the best-dated geological event we ever had is wrong, said Prosanta Chakrabarty, LSU Associate Professor in the Department of Biological Sciences and Curator of Ichthyology at the LSU Museum of Natural Science. His research on the evolution of freshwater and marine organisms in Central America was part of the study with colleagues at the Smithsonian Tropical Research Institute, American Museum of Natural History and University of Gothenburg, which included living and extinct mammals, birds, plants, fish and invertebrate animals published by the Proceedings of the National Academy of Sciences.
The researchers found large pulses of movement among these plants and animals between North and South America from 41 million, 23 million and eight million years ago. These coordinated spikes in migration imply that geological changes in Central America, such as landmass formation and new freshwater corridors, were aiding migration for many kinds of plants and animals.
Before, South America was thought of as an island with no communication until 3.5 million years, so the only way to explain such high biodiversity was to say that it accumulated extremely fast. Now, with a longer history, we know that processes and patterns took a lot of time to form, said Christine Bacon, lead author of the study and associate researcher at the University of Gothenburg. Our results change our understanding of the biodiversity and climate, both at the regional and global levels.
Until recently, most geologists had determined the land connecting North and South America, the Isthmus of Panama, had formed 3.5 million years ago.
But new data shows that this geological event, which dramatically changed the world, occurred much earlier. In a comprehensive biological study, researchers have confirmed this new information by showing that plants and animals had been migrating between the continents nearly 30 million years earlier.
This means the best-dated geological event we ever had is wrong, said Prosanta Chakrabarty, LSU Associate Professor in the Department of Biological Sciences and Curator of Ichthyology at the LSU Museum of Natural Science. His research on the evolution of freshwater and marine organisms in Central America was part of the study with colleagues at the Smithsonian Tropical Research Institute, American Museum of Natural History and University of Gothenburg, which included living and extinct mammals, birds, plants, fish and invertebrate animals published by the Proceedings of the National Academy of Sciences.
The researchers found large pulses of movement among these plants and animals between North and South America from 41 million, 23 million and eight million years ago. These coordinated spikes in migration imply that geological changes in Central America, such as landmass formation and new freshwater corridors, were aiding migration for many kinds of plants and animals.
Before, South America was thought of as an island with no communication until 3.5 million years, so the only way to explain such high biodiversity was to say that it accumulated extremely fast. Now, with a longer history, we know that processes and patterns took a lot of time to form, said Christine Bacon, lead author of the study and associate researcher at the University of Gothenburg. Our results change our understanding of the biodiversity and climate, both at the regional and global levels.
