prophex
The mentality of evolution, "only the strong survive", "kill or be killed" is sort of disturbing.
This is a huge dumbing down of evolutionary process.The phrase is survival of the fittest.Strength is one aspect that may work at one scenario and doom at another.In the contest of life where the winner is that one which survives because its muscle power was greater is limited to that event where it is useful.With powerful muscles normally an increase in size is a corresponding factor.
Now in a situation where a predator is present whose strength is far in excess of the strongest individual fleeing into tight rock crevices may be the only recourse to survival and if the powerful ones are of such dimension that they do not fit into a crevice to escape they therefore become lunch.Kill or be killed is the law prevalent within nature.However it need not be killing for advantage of food resources or as meat for the animals survival it may just be for defense or,as in microbial life,a result of processes within a larger individual.
A harsh way of seeing it, don't you think?
Harsh is not the case just merely the state of reality.Nature is totally impersonal.It neither cares nor does not care for the results of the processes of interaction between participants.Death of an individual becomes opportunity and sustenance for another.