The first review of the global impact of humans on tropical forests in the ancient past shows that humans have been altering these environments for at least 45,000 years. This counters the view that tropical forests were pristine natural environments prior to modern agriculture and industrialization. The study, published today in Nature Plants, found that humans have in fact been having a dramatic impact on such forest ecologies for tens of thousands of years, through techniques ranging from controlled burning of sections of forest to plant and animal management to clear-cutting. Although previous studies had looked at human impacts on specific tropical forest locations and ecosystems, this is the first to synthesize data from all over the world.