Playing devil's advocate: Is there actually a difference between genocide and survival of the fittest? If the Etruscan people were a superior culture with a sup

Playing devil's advocate: Is there actually a difference between genocide and survival of the fittest? If the Etruscan people were a superior culture with a superior fighting force, they would have defended themselves from the Romans and they'd still be around. Likewise if the panda was better adaptable, we wouldn't be struggling to save the species. If the saber-toothed tiger died out because they were out-competed by the other species around them, we call that natural selection. If the Carthaginians died out because their neighbors had a better fighting force, we call that genocide. But the only difference is... what, exactly?