The latest explosion in orchid evolution.

摘要

New evidence provided by paleobotanists and geologists, who study the Holocene Epoch in the neotropics of South America, illustrates how recently and how rapidly certain orchid genera must have mutated into many new species during the past few centuries. Among other factors, slash-and-burn agriculture (swidden cultivation) kept dense primary forests from developing in the Holocene, until illnesses introduced by European explorers drastically disseminated the native human population. This allowed primary forests to cover extensive territories and thus explains the fairly recent explosion in orchid evolution in the area..