Perseverence signals fitness

If a species has been around for a long while, it’s likely not only it is going to continue being around for a long while, but that it also possesses some sort of optimal fit on its environment. Assuming that it is ecological fitness that enables a species to survive through long-tail existential catastrophes, perseverence is a strong indicator of fitness. However, to get a more complete picture of fitness, one should take both the time-wise perseverence and space-wise abundance into account.