OHIO Professor Nancy Stevens helps clarify the evolution of African ecosystems in a paper published in Science

Dr. Nancy J. Stevens of Ohio University is a Distinguished Professor in the Biomedical Sciences Department of the Heritage College of Osteopathic Medicine and a co-author of a published paper. chemistry Funded by the National Science Foundation, which documents the evolution of grassland ecosystems on the African continent.

collaboration Together with a large team of geologists and paleoanthropologists from universities around the world, led by researchers from Baylor University and the University of Minnesota, the team identified nine Early Miocene fossils in the East African Rift Valley of Kenya and Uganda. Synthesizing data from localities, grassland biomes dominated by grasses with C4 photosynthetic pathways in East Africa arose more than 10 million years ago.

According to this paper, previous reconstructions of early Miocene ecosystems, 15 to 20 million years ago, indicate that equatorial Africa was covered with semi-continuous forests and had a previously uncommon warm season (C4). suggesting that it had an open habitat dominated by grasses. 8-10 million years ago. C4 refers to different pathways that plants use to capture carbon dioxide during photosynthesis. C4 plants produce four carbon molecules and are better suited to warm or hot season conditions under moist or dry environments.

As researchers gather expertise on the geological features, isotopes and fossils found at the site, the paradigm of contiguous forests covering early Miocene equatorial Africa already includes an open environment of C4 grasses. migrated to a more complex mosaic of habitats.

The results of this study push the earliest evidence of C4-grass-dominated African habitats back over 10 million years, and are important for the evolution of primates and the origin of tropical C4 grassland and savannah ecosystems across the African continent. has a meaning. In the world.

“I was skeptical that we would find C4 plants at some sites, but I didn’t expect to find them at so many sites and in such abundance,” said lead author and associate at Baylor University. Professor Daniel Peppe said. .

A key aspect of this work is that the team combined a diverse body of evidence, including geology, fossil soils, isotopes, and phytoliths (phytosilica microfossils), to arrive at their conclusions.

“This study is a major triumph for collaborative science and documents the value of looking deeper, over time and more holistically across disciplines to better understand the ecological context of plant and animal evolution.” It’s changing,” Stevens added. “This is an exciting time to explore environmental change, and projects like this will generate important data for charting future decisions about resource use and well-being on the planet today.”