A species is a group of living organism consisting of individuals that can interbreed.
There are different types of species concepts. For instance, Ecological species concept defines species are a group of individuals that share the same ecological niche.
Therefore, when the biologist did not consider the physical similarities of the wolf spiders rather their ecological niche to group them.
I shows he utilized the ecological species concept.
they compare fossils to other fossils to see if skeleton changes are observed in a species over time it indicates that there is genetic change going on within the species