The average species age is necessarily lower than the average species duration.
Additionally, the fossil record measures species in paleontological terms, a paleontological “species” is not a species in biological terms, but a group which cannot be distinguished from each other by fossilized remains. Paleontological species duration sets the upper bound on biological species duration; in practice, biological species duration is shorter.
Species originating more than 2.5 million years ago which were not capable of enduring glaciation periods would have died out when they occurred. The origin window for species without adaptations to cope is the last ten thousand years. Any species with a Pleistocene origin or earlier has persisted through glaciation periods.
The average species age is necessarily lower than the average species duration.
Additionally, the fossil record measures species in paleontological terms, a paleontological “species” is not a species in biological terms, but a group which cannot be distinguished from each other by fossilized remains. Paleontological species duration sets the upper bound on biological species duration; in practice, biological species duration is shorter.
Species originating more than 2.5 million years ago which were not capable of enduring glaciation periods would have died out when they occurred. The origin window for species without adaptations to cope is the last ten thousand years. Any species with a Pleistocene origin or earlier has persisted through glaciation periods.