"Name one non indegenous species of something that is left unchecked in a different environment." I am not sure I follow that. Are you suggesting that alien species are not controlled because they lack competition from local species, or suffer from local pests or diseases? That is a widely held if still contested theory. But it does not explain why 99% of introduced species are not problematic.
You can't follow it. Name one species not indegenous to the area that is left to its own devices. That easier for you. What I am suggesting is all species as a general rule should be checked or else they will run riot/destroy other natives of the area.
Here's an easier one for you I ll even ask you a question and you can give me a percentage If we were to introduce the African lion and the American mountain lion into the UK in reasonable numbers and left them to it , what would happen as a percentage factor
Correct I was just quotin but yes we drove them out of Kuwait . Saddam had already used his WMDS on his own people then decided to invade Kuwait then attack Israel . The coalition issued Saddam with umpteen resolutions but he gave them the middle finger
At least half the British flora of around 2000 Sp have been introduced my humans. The number that are recognised as invasive pests that need to be "checked" are about 10. Of those about as many are natives as introduced. The same is not true in the USA, for reasons that are not clear. But their literature on the problems with introduced species tends to covered here. so we assume we have the same problem.