The phrase was first coined by the philosopher Herbert Spencer, an advocate of laissez faire - the doctrine of unrestricted freedom for private interests.
"Survival of the fittest" was Spencer's crude interpretation of Darwin's more explicit and refined term: natural selection.
"Survival of the fittest" is an unfortunate phrase because it remains open to interpretation, as well as having a quasi-fascist connotation.
Indeed some believe that Hitler latched onto the Spencerian phrase as an endorsement by Darwinism for his deranged belief in Aryan racial supremacy - something that Darwin would have certainly abhorred.
Douglas Glossop
Bognor Regis