Synchronicity is hitting me today. I ran across this article in Nature (linked via slashdot) about a pair of twins who aren't identical twins nor fraternal twins -- they're both chimeras. One of them is a "true hermaphrodite" (having both ovarian and testicular) tissue. This leads to an obvious question: how many intersex children are chimeras?
(And how many anti-science right-wingers heads are exploding over this? It's got a bunch of stuff they clearly can't handle: science, evolution, gender ambiguity.)
And then there was article in the New York Times (linked via Carl Zimmer's blog) that details the discovery that marmosets are almost invariably chimeras -- they are almost always fraternal twins who basically hybridize at the cellular level in utero.
The world is far stranger than we could ever imagine.