With a body length of only about six inches, the pygmy marmoset is the world's smallest monkey. Yet it can jump more than sixteen feet. That would be like a six-foot tall person being able to jump almost 200 feet. So if you're a comic book publisher looking for an idea for a new superhero, "Captain Marmoset" would be a fine choice.
But what really makes the marmoset an extraordinary monkey is that all 22 species exhibit something called germline chimerism, a phenomenon not known to exist in any other primate species. A chimera is an organism that has tissues from two distinct genetic lines; for example, hair taken from one part of a marmoset might have different DNA than hair from another part of the very same marmoset.
Here's how it happens: Marmosets almost always give birth to fraternal twins. In utero, the placentas for each twin fuse together, allowing cells from one embryo to mingle with those of its twin and vice versa. Over half of male marmosets have chimeric sperm. That means that, if one of these marmosets reproduce, his offspring will have his brothers' DNA. Which kind of complicates the phrase "I'll be a monkey's uncle!"
