The Great Mental Models, Volume 2: Physics, Chemistry and Biology

by Shane Parrish

In any system, it’s natural for parts to continuously wear and need replacing. This is true of ecosystems. Extinctions are a ubiquitous feature of life on earth, as a sort of meta natural selection. The same selection process that applies to individuals is true for species as a whole. The catch is that the same evolutionary process that ensures a species’ survival can also be its downfall. Natural selection within a stable environment tends to be a process of refinement. A species will become more and more tuned to the precise adaptations it needs to survive. This is ideal in reliable conditions, but it can mean a species lacks the resilience it needs to survive any changes. So while the best-adapted organisms may be the strongest during normal conditions, they may struggle to survive volatility. Generalist species are far more resilient than specialists. A rat or a cockroach can survive almost anywhere, a panda less so.