Autotrophs since they are self-feeders and make their own food instead of relying on others (the opposite is heterotrophs)
Take for example the group of prokaryotes against eukaryotes. They may be similar in a way that they contain cells with organelles such as mitochondria, ribosomes, cytoplasm, and many more. But they may differ in the presence of a cell membrane and a nucleus. Eukaryotes have cell walls and a nucleus, while prokaryotes don't have.
This is referred to as allopatric speciation where species are separated geographically and evolve into two different species over time
