Twins: Nature's Amazing Mystery

adult alike amniotic sac appear babies believe blood born Bouchard boys cell child chronogenetics conjoined twins dermatoglyphics discovered disease dizygotic doctors early experience fantasy father feel fertilized fetoscopy fetus fetus in fetu fetuses fraternal twins genes genetic George Engel gestation girls Gregor Mendel hereditary heredity hospital human identical twins idioglossia individual infants instance Kloepfer lives look marriage married Minnesota monozygotic Mothers of Twins multiple births names normal pairs of twins parents partner patterns percent person physicians placenta pregnancy problems psychological psychologists question relationship reported says scientific scientists separate sets of twins share Siamese siblings similar singletons story study of twins Supertwins tell teratomas tests things tion traits tribe triplets twin births twin brother twin expert twin pairs Twin Registry twin studies Twins Clubs twins reared twinship ultrasound vanished twin womb women Zazzo zygosity