A new study led by researchers at Washington University in St. Louis and the Missouri Botanical Garden has uncovered a surprising layer of diversity in tropical forests. Not only are the forests populated by a dizzying number of tree species, but each of those species takes a different approach to chemistry, increasing the array of natural compounds that provide important functions for the plants — and potentially for humans. The research helped clarify the ecological and evolutionary forces that make tropical forests such hotbeds of biodiversity. While the team wasn’t specifically looking for compounds that could be useful for humans, their findings underscore the value of tropical forests as natural factories of plant chemicals that could have important uses in medicine and other fields, said Jonathan Myers, a professor of biology in Arts & Sciences at WashU. “Tropical plants produce a huge diversity of chemicals that have practical implications for human health.”