Darwin didn’t coin the phrase “survival of the fittest.”

The expression "survival of the fittest" was coined by Herbert Spencer; Charles Darwin not only did not use it, but he also opposed it. This is one of the interesting facts about Charles Darwin. He goes so far as to link the evolution of compassion to the success of human evolution (and even the evolution of "lower animals"). The phrase "survival of the fittest," made famous by British naturalist Charles Darwin in the fifth edition of On the Origin of Species (published in 1869), argued that organisms most adapted to their environment are more effective at surviving and reproducing.

The most change-adaptive species is the one that endures, not the most brilliant or the strongest. The genuine words of Charles Darwin regarding survival. Darwin claimed that all species share a common origin, that species can change through time, and that new species develop from existing ones. According to this theory, each species has a distinct set of heritable (genetic) differences from the common ancestor that have developed gradually over extremely long time periods.

Herbert Spencer's The Principles of Biology, published in 1864, examined biology in terms of issues like Function, Adaptation, and Variation. Spencer first used the phrase "survival of the fittest" in this work to mean "the most suitable to its surroundings."