Pirwhana;1692505; said:Life is full of one species taking over anothers territory. Look at us humans. Not to mention past life. It is how we got our species today. One could argue that it is just evolution and not evil. We forget we are part of nature too. Don't get me wrong I am not pro releasing fish, I am just saying species taking over and breeding with others has been happening since the dawn of time. So your so called natives are the result of hybridizing and species being taken over.
Lindsey
Yeah, but species migration and hybridization is typically considered to be a gradual process. The ecosystems we see right now are by no means static, but the reason why they are relatively stable is because of co-evolution and species associations that have occurred over a long period of time.
That is why native organisms and their respective diseases typically aren't that detrimental to the population as a whole - if some fish disease was highly virulent and lethal, chances are it wouldn't be around for too long, because the host would be wiped out... and we wouldn't see them occuring right now. But if you add an invasive disease into the equation, it is doing what comes naturally, and can wipe out the host that it wasn't originally associated with.
If you throw in a foreign organism from another part of the world and it manages to survive and reproduce, the changes to the dynamics can be huge. We consider those changes negative because we like our native species and the way our ecosystem functions... a perpetual cycle that provides us with food, water, shelter, health, and an economy is pretty nice, and worth protecting
The problem is when a native species gets pushed out by an invasive one, it's role in the ecosystem may not be fulfilled.