Hello,

How cancer cells and pathogens can behave if not disturbed and get
stable environment to survive in view of following quote;

"The biologist Lynn Margulis, famous for the work on endosymbiosis,
contends that symbiosis is a major driving force behind evolution. She
considers Darwin's notion of evolution, driven by competition, as
incomplete, and claims evolution is strongly based on co-operation,
interaction, and mutual dependence among organisms. According to
Margulis and Sagan (1986), "Life did not take over the globe by combat,
but by networking." As in humans, organisms that cooperate with others
of their own or different species often outcompete those that don't.
http://en.wikipedia.org/wiki/Symbiosis"

It is indicative that bacteria etc. may divide by replication--asexual
reproduction, when environment is stable or favourable to them but may
opt for genetic recombination somewhat "sexual reproduction" if
environment is unfavourable.

Best wishes.