Some species thrive really well. They do so by making their environment better for them. They are a boom species.
Some species trade off regularly for top spot in the ecological niche. They are flip flop species.
Find out more.
(This is part one of Save Mankind with Neolithic Park.)
See this discussion in text at http://www.whiteworld.com/technoland/stories-nonfic/2008-stories/Eco-Flip-Flops.htm