How Columbus’ voyages accelerated the homogenisation of Earth’s biodiversity [Commentary]

Christopher Columbus was a legendary 15th-century Italian explorer whose “misadventures” opened the way for large-scale biogeographical homogenisation. Over the past 500 years, since Columbus first sailed west across the Atlantic Ocean to reach the “New World”, Earth has witnessed unprecedented cross-boundary human movement and the exchange of living organisms. These movements have brought about major shifts in the geographical distribution of microorganisms, plants and animals. While thousands of introduced plants and animals have acquired the deplorable status of “invasive alien species”, introduced pathogenic microorganisms, such as those that cause smallpox, cholera, sexually transmitted diseases and plague, have been major culprits in wiping out indigenous human populations and cultures across the world. History has also shown that introduced phytopathogenic microorganisms have devastated agriculture, causing widespread famine and human suffering. The post-Columbus transformation of Earth’s biogeography has proved catastrophic. In 1995, when UNESCO celebrated the silver jubilee of its Man and the Biosphere Programme, the event was held in Seville, Spain, where Columbus was laid to rest. The choice of venue could have hinted at Columbus’ unintentional contribution to the ecological chaos that Earth has witnessed over the past 500 years. Biogeographical periods shaping the biosphere Biogeography is the science that seeks to understand the patterns of geographical distribution of organisms and the reasons behind them, as well as the ecosystems in which organisms develop and coexist. Over its long history, Earth has witnessed at least five landmark biogeographical periods: (1) the pre-drift biogeographical period, which lasted until around the time tetrapods…This article was originally published on Mongabay