It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change. – Charles Darwin, naturalist and author (1809-1882)
When the expression “Survival of the Fittest” gets thrown around in conversation, we usually interpret that phrase to mean that only the strongest, the meanest, the most ruthless will come out on top in the end. But that is not what Darwin was saying. Fittest means the organism that could adapt to an ecological environment or niche — in other words, it fits in, not that it was in the best physical shape. It also implies that survival implies a capacity to listen, to adjust to the environment and to take fullest advantage of the conditions.