In fact, many alien invasions are caused by humans

Species are sometimes introduced into new habitats through natural factors,like storms,ocean currents,or climate shifts.The majority of invasive species,though, are introduced by humans.Often this happens unintentionally,as when the zebra mussel was accidentally brought to Lake Erie by cargo ships.But as people migrate around the world,we have also deliberately brought our plants and animals along,rarely considering the consequences.But now that we're learning more about the effects of invasive species on ecosystems,many governments closely monitor the transport of plants and animals,and ban the imports of certain organisms.But could the species withthe most drastic environmental impactbe a group of primates who emergedfrom Africa to cover most of the world?Are we an invasive species?