I’ve used the phrase Survival of the fittest in columns in the past. One of these columns ran again last week and sparked a debate that played out in the comment section. It reminded me that this is one of those phrases that everyone uses but not everyone knows what it means. In fact, it’s meaning when used in evolution has morphed over time into something never intended by at least one of it’s early adopters.

When I say “survival of the fittest” you may think that translates to survival of the strongest or fastest or biggest or smartest. But that was never how Mr. Darwin intended it.

The phrase itself didn’t originate with Charles Darwin. It never appeared in the original edition of On the Origin of Species. It came from the British polymath Herbert Spencer, who used the term in 1864 in Principles of Biology. Darwin did approve of it; however, and adopted it in subsequent editions of his book.

For Darwin, the phrase was intended to mean “better designed for an immediate, local environment.” The use of the term “fit” may be leading to the confusion here. We use fit to mean physical superiority. This is where the “faster, bigger, stronger” interpretation came from. But Darwin meant a better “fit” with the environment. The difference is crucial.

Herbert Spencer’s use of the term is probably closer to how it is commonly interpreted today. Spencer applied the concept of evolutionary competition to everything he saw, including economics and sociology. If you follow the phrase’s lineage down this path, we see how the idea of physical superiority became intertwined with the concept of fitness. Unfortunately, this interpretation led to the ethically murky waters of Social Darwinism and cutthroat competition.

Why this semantic lesson of the day? Because I think there’s something important here that serves as a lesson in volatile times. Survival of the fittest is a phrase that’s seldom used by scientists today. Darwin intended it to be a substitute for natural selection, but we now know that the survival of species has little to do with survival between individuals and much more to do with the ability to adapt to sudden changes in the environment or expand into under utilized ecological niches. Those that can pivot quickest to take advantage of environmental opportunities and recover from catastrophic external factors are the ones that will flourish. Survival is not about physical superiority, but rather about adaptability.

When we stick with Darwin’s intended meaning, we discover two amazing things: 1) Physical superiority depends to some extent on a stable playing field; and, 2) The more dynamic the environment, the more important adaptability becomes.

In stable environments where little changes from day to day, natural selection tends to build scale in terms of strength and size. But this building of physical superiority is tied to that environment. The scaling is done on the scaffolding on a stable ecosystem. When that ecosystem changes dramatically (think an asteroid slamming into the earth) the physical advantages that were formed in the previous era can become disadvantages in the new one (think dinosaurs).

In environments where change accelerates, adaptability trumps all. And it’s very rare to see adaptability and scale come in the same package. One is usually sacrificed for the other.