The Rh factor in blood types is short for Rhesus factor, discovered in rhesus macaques. Scientists have long studied macaques to learn things about ourselves. They’re tough, adaptable monkeys that can be found living in cities and temples. There are 22 species of macaque in the world, their natural ranges reaching as fast west as Gibraltar and as far east as Japan. Now they have all the DNA from a macaque. But it was not until today that scientists had a third primate genome to study. The way through this impasse is to compare chimpanzees and humans to a third species–ideally another primate. It might have started out as AAAA, and in humans the final A became T and in chimps A became C. It’s even possible that the ancestral version was neither. But it’s also possible that humans have the ancestral version, and in chimps the T flipped to C. (Real genes are hundreds or thousands of nucleotides long.) It’s possible that the ancestor of humans and chimps had the AAAC version of the gene, and in humans the C mutated to T. Imagine, for the sake of brevity, that the human version of a gene is AAAT, and the chimpanzee version is AAAC. If you find two versions of a gene that are nearly–but not quite–identical in humans and chimpanzees, it’s hard to know for sure how that difference evolved. One of the biggest surprises came when one team of researchers concluded that the ancestors of chimpanzees and humans interbred for over a million years, producing hybrid humanzees.īut there’s a limit to how much you can learn from just two genomes. (I wrote about the first wave of chimp/human studies here). Scientists compared the two genomes to get a sense of what the genome of our common ancestor looked like, and how the genomes of both species have changed over the past few million years. The first draft of the human genome was published in 2000, and in 2005 came the genome of the chimpanzee–our closest living relative. But in the past few years scientists have begun to pore over a new record: the one that is inscribed in our genome and the genomes of other apes and monkeys. Until now, most of those clues have come from fossils and studies on the behavior and physiology of apes and monkeys. By comparing ourselves to these other primates, scientists can get clues to our evolution over the past 25 million years. Those primates were not just the ancestors of ourselves, but of all the other apes–chimpanzees, bonobos, gorillas, orangutans, and gibbons–along with the monkeys of the Eastern Hemisphere, such as baboons and langurs. If the primate you’re trying to place is not a human, gibbon, chimpanzee, bonobo, orangutan, or gorilla (or a lemur, loris, or tarsier), then it’s a monkey.Trace your genealogy back 25 million years, and you’ll meet long-tailed monkey-like primates living in trees. There are only a handful of ape species, while there are hundreds of species of monkeys. However, perhaps the best way to remember, like with so many things, is rote memorization. While both monkeys and apes can use sounds and gestures to communicate, apes have demonstrated higher ability with language, and some individual apes have been trained to learn human sign languages. Apes are generally more intelligent than monkeys, and most species of apes exhibit some use of tools. Although you can’t recognize this difference on sight, apes have an appendix and monkeys do not. Their bodies are different in other ways too: monkeys are generally smaller and narrow-chested, while apes are larger and have broad chests and shoulder joints that allow them to swing through trees (while some monkeys also have this ability, most of them are built for running across branches rather than swinging). Almost all monkeys have tails apes do not. The quickest way to tell the difference between a monkey and an ape is by the presence or absence of a tail. But when you look at a gibbon or a marmoset, how do you know which is a monkey and which is an ape? As distinguished relatives, we should probably be able to tell them apart. Monkeys and apes are both primates, which means they’re both part of the human family tree.

Chimpanzee monkey peace fingers