Twins were the norm for our ancient primate ancestors − one baby at a time had evolutionary advantages

"Twins have been rare in human history and for that reason can seem special. ...... .......Our recent research suggests that twins were actually the norm much further back in primate evolution, rather than an unusual occurrence worthy of note. Despite the fact that almost all primates today, including people, usually give birth to just one baby, our most recent common ancestor, which roamed North America about 60 million years ago, likely gave birth to twins as the standard." More at The Conversation ➜