We've had bacteria that can digest nylon production byproducts since 40 years after nylon was invented: http://en.wikipedia.org/wiki/Nylon-eating_bacteria .

After 20 years of observing E. Coli in a medium that had lots of citrate, one (of twelve) population became able to digest citrate: http://en.wikipedia.org/wiki/E._coli_long-term_evolution_exp... .

There were only about 400 years between the Medieval Warm Period http://en.wikipedia.org/wiki/Medieval_Warm_Period and the Little Ice Age http://en.wikipedia.org/wiki/Little_Ice_Age , but Europe still has a perfectly good ecosystem.

The finches on the Galapagos Islands have been observed closely over a long period, and seen to change from year to year in response to climate (and therefore food supply) variations: http://en.wikipedia.org/wiki/Peter_and_Rosemary_Grant .

I think you're seriously overestimating the time needed for ecosystems to adapt, and for lineages of organisms to change significantly.