There are thousands of species on planet earth, probably millions.
Each species on Earth, according to evolution has a common ancestor.
But if every species on earth had a common ancestor, then all of the animals that existed at this time would have interbred with each other and as a result, there would either be only be one species on this planet, or no species on the planet if the species starved to death due to our distant ancestors interbreeding with the ancestors of every other species(which was the same species back then, so viable offspring would be produced)
This is what would happen if science’s view on the origin of life was true.
But we know millions of species exist on this planet. The alternative to evolution is creationism:
With creationism, every species was distinctly made by a higher power. This explains the millions of species we know exist today.
If evolution is real, the animals of the distant past would have interbred into unification. If creationism is real, it helps explain why different species exist today.