If you read "The Sixth extinction" it talks a lot about this. Her hypothesis is that the main cause of this is in fact humans, but not human-caused climate change -global trade and travel.
"Kolbert then explains that global trade and travel are creating a virtual "Pangaea", in which species of all kinds are being redistributed beyond historical geographic barriers. This furthers the first chapter's idea that invasive species are a mechanism of extinction."
"Kolbert then explains that global trade and travel are creating a virtual "Pangaea", in which species of all kinds are being redistributed beyond historical geographic barriers. This furthers the first chapter's idea that invasive species are a mechanism of extinction."