Humans are polyclonal beings since each one of us is born of
a unique fertilization event. Rarely, however, two babies can
develop from a single embryo producing monoclonal babies.
Referred to as monozygotic (MZ), identical twins are true
reproductive clones; like Dolly they share a genome but
breathe a sovereign existence.
Taking place every 50 seconds worldwide, MZ twinning
is more prevalent than any genetic disease yet its cause
has remained enigmatic.