> ...the introduction of a wider genetic or cultural pool does not cause an ecosystem collapse. Here is my point: What exactly do you mean by "an ecosystem col

> ...the introduction of a wider genetic or cultural pool does not cause an ecosystem collapse. Here is my point: What exactly do you mean by "an ecosystem collapse"? There are hundreds of invasive species only here in the US. No part of the country is untouched. Have all the US ecosystems collapsed? Have any?