Human mutants. Part 2, The dangerous womb.

The second in a three-part series in which biologist Armand Leroi discovers how studying congenital abnormalities can reveal new information about human development. The second part explores what can go wrong in an embryo when it is developing in the womb. Armand Leroi traces the history of embryology through discoveries in molecular biology and latterly genetics. He then looks at the history of a number of birth defects, most particularly conjoined twins and people with mermaid syndrome. We meet Tiffany Yorks, a 16-year-old girl from US who is the only surviving person to be born with mermaid syndrome. Finally we look at the, often cruel, work of Jill Helms at the University of California who is experimenting on animal embryos in order to create mutant animals, for instance a pig with two faces called 'Ditto.'