A National Science Foundation grant of $405,000 will fund Mark Bush and biological sciences graduate students on summer field research explorations to Brazil, Peru and Panama over the next three years. They will investigate the cause of the largest recent mass extinction of megafauna, or large mammals. The extinction event occurred between 15,000 and 9,000 years ago—a time of rapid warming at the end of the last Ice Age and the arrival of humans in the Americas.
Rapid climate change and over-exploitation by hunters vie as competing explanations for the loss of over 50 genera of large mammals, such as sabre-toothed cats, mastodons and giant ground sloths. Understanding the vulnerability of large mammal populations to sudden warming is relevant to conserving modern mammal-rich areas such as the American West, Alaska and the Serengeti.
The researchers will collect the layered muds that were continuously deposited from 25,000 to 5,000 years ago in ancient lakes at 13 settings in Peru, Brazil and Panama. By analyzing fossil pollen, charcoal, diatoms (algae) and fungal spores, they will document climate change, human arrival and the decline of large mammal abundance. This evidence will help determine the timing and causes of the large mammal extinction.
Bush will recruit undergraduates as well as graduate students for international field work and to participate in the publication of findings. “These experiences are often a truly transformative experience for undergraduates,” said Bush.
Bush’s research website, in English and Spanish, is http://research.fit.edu/paleolab. The addition of Portuguese pages is planned.