The study focused on 85 tree species known to have been domesticated by Amazonian peoples for food, shelter, or other uses over the last several thousand years. The researchers found that throughout the Amazon basin these species were five times more likely to be common in tree surveys than non-domesticated species. Domesticated species were also found to be more common and more diverse in forests closer to archaeological sites. These 85 domesticated trees include well-known commercial species, such as cacao, açaí, and Brazil nut. It was found that a quarter of Amazonia’s domesticated species are widely distributed in the basin and dominate large expanses of forest. These results clearly indicate that the Amazonian flora is in part a surviving heritage of its past inhabitants.