how does variability within a species affect its survival?

Question

how does variability within a species affect its survival

Answer 1

Hi. It allows a better chance that one of the variations will be better adapted to the current environment.

Answer 2

Consider bacteria. We have an entire industry based on destroyong the damned things. The problem is variability. Some bacteria are more resistant to a particular drug than others. Usually just a tiny percent. What happens when patients are treated with antibiotics? This tiny percentage of better adapted bacteria sometimes survives. It can breed. eventually that particular strain of bacteria becomes more dominant and if it is dangerous to humans, people begin to die in steadily greater numbers when exposed to that bacteria. Industry gears up and arrives at a new antibiotic that will kill that strain, but as before, some of its member, because of genetic variability have some defense against the new antibiotic drug...