If the definition of species is that individuals of the same species are capable of producing fertile offspring why were humans and Neanderthals able to reproduce? Are we the same species?
In: Biology
As others have said, what you describe is a general rule about species, but not an absolute law. Even Darwin remarks in the Origin of Species that the line between species and variation is pretty blurred in example like hens
Yes, for this reason, Neanderthals are often referred to as a subspecies of human with the classification of Homo sapiens neanderthalensis, as opposed to our classification of Homo sapiens sapiens.
But this does also demonstrate a more common theme that species classification is hard and nature isn’t designed to be put into nice boxes.
The problem is that when we were evolving, nature didn’t really care about the distinctions that we would eventually make. Species in particular is a super nebulous term. Does it mean that all sexually mature members of one species must be able to make fertile offspring with all other ones of the opposite sex? What if there’s two groups where males of species A can viably mate with females of species B, but not the other way around. Are they the same species?
Questions like that make defining “species” to be arduous at best, and sisyphusian at worst
That’s not the only defining trait of a species. Many different species are capable of producing offspring. Lions and Tigers for example
That’s not the complete picture. We often define a species as two individuals that can interbreed, but that’s more of a rule of thumb. In the real world there’s many examples of interspecies breeding, like mules- the offspring of a donkey and a horse. Many times the distinction of species has to be made genetically or based on other characteristics like habitat/niche.
Neanderthals were a different species genetically but were similar enough to humans to breed with them.
Latest Answers