What is the common phrase coined with the theory of evolution?

survival of the fittest

I guess you are referring to 'survival of the fittest'. You may also mean 'natural selection'. When organisms produce offspring that will naturally have variations (due to mixing of chromosomes and mutations), some of these variations may give the organism an advantage against others, and result in them being more likely to survive (this is survival of the fittest). With the organism having an increased chance of survival, there will also be an increased chance of it reproducing and passing on the features that increased its chance of survival. This is 'natural selection' where the favourable feature has a higher chance of being selected by nature to be passed on.

Survival of the fittest- meaning those individuals with more favourable characteristics or alleles made them more likely to survive at that particular time in those particular conditions, passing on to future generations.

Survival of the fittest

Survival of the fittest.

Survival of the fittest, or natural selection.