"Darwin first used Spencer's new phrase 'survival of the fittest' as a synonym for 'natural selection' in the fifth edition of On the Origin of Species, published in 1869.[2][3] Darwin meant it is a metaphor for 'better adapted for immediate, local environment', not the common inference of 'in the best physical shape' [4]. Hence, it is not a scientific description,[5] and is both incomplete and misleading."
"Darwin first used Spencer's new phrase 'survival of the fittest' as a synonym for 'natural selection' in the fifth edition of On the Origin of Species, published in 1869.[2][3] Darwin meant it is a metaphor for 'better adapted for immediate, local environment', not the common inference of 'in the best physical shape' [4]. Hence, it is not a scientific description,[5] and is both incomplete and misleading."