[pfdietz]

To some extent it's a matter of definition, and whether being caused by humanity means it's bad. After all, the native earthworms would eventually have migrated north and caused similar changes.

Is it bad that redwoods are doing very well in the UK?

[happosai]

The problem isn't "because it was caused by humans" per se. Invasive species because of the speed they migrate. Adapting genetically changing environment is the core of life in our planet, but it takes thousands of generations. Humans spread invasive species much faster than the local fauna can adapt.

[darkwater]

Very true. But also, if the invasive specie didn't naturally evolved in the foreign place, will it actually last there for 10.000s years? Difficult to know since we won't be there probably but still...