I'm sort of resistant to the idea since humans produce a lot of food and if humans vanish the food production sort of almost stops, is it wrong to think so? Also isn't/aren't bacteria and other single cellled life forms the 90+% of biological mass (already) so. I was sort of referring to complex life and life forms.. ...
Depending on the triggering events, plant life should still continue as they retake the earth. The organic matter will continue to provide food sources as bacteria awaken and go dormant with the availability of food and water. I follow a lot of the studies surrounding Chernobyl, and how the environment has reclaimed the city. There will still be organisms that adapt, but the simplest things will prevail, in this case specifically as they can adapt easier. As far as more complex organisms, a similar thought prevails with any organism that relies on dead or decaying matter will have an advantage. In this paradigm, your cockroach would probably have excellent odds, but will compete for food, resulting in a self limiting population.
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