I thought obvious that the joke refers to the misconception some people host that 'homo sapiens' is a less evolved species than modern people, something we out-evolved.
Although, debatably, homo neanderthalensis is not a subspecies of homo sapiens, thus negating the need for a homo sapiens neandterthalensis and homo sapiens sapiens classification differentiation to exist, making homo sapiens always the modern man (who yes, is also an ugly caveman) and homo neanderthalensis the most recent full time ugly caveman.
Homo sapiens sapiens, in anthropology and paleontology, the subspecies of Homo sapiens that consists of the only living members of genus Homo, modern human beings. Traditionally, this subspecies designation was used by paleontologists and anthropologists to separate modern human beings from more-archaic members of Homo sapiens.
Homo = person/man
Sapiens = wise
What's this bullshit about?
And it seems they didn't live in caves either.
The only thing I can think of is that it's implying that as you get smarter you find cavemen more attractive and consider modern humans to be ugly.
I thought obvious that the joke refers to the misconception some people host that 'homo sapiens' is a less evolved species than modern people, something we out-evolved.