I recently came across this article. It describes the phenomenon of semi-identical twins. Being part fraternal and part identical, this type of twinning is extremely rare and most likely a great ice breaker.


Ryan

Not quite as strange, but still:

"Marmosets (Callithrix kuhlii) are unusual in that most pregnancies result in non-identical twins, and a high proportion of those result in chimerism. Genetic analysis of these twins shows that all tissues - including skin, hair, brain, lung and muscle - may contain cells derived from the sibling twin."

http://www.newscientist.com/article/dn11464-marmosets-may-carry-their-siblings-sex-cells.html

Nature doesn't leave a rock unturned does it?