Extracts from unpublished papers on the methods used by a Chinese scientist to genetically modify the embryos of two girls reveal a series of potentially dangerous problems with the procedure and ethical shortcomings.

We look at the mechanism behind the formation of our facial features and how this is linked to our evolution, scrutinise the impact of current emissions on global climates and see why lithium, used in batteries and medicines, is now a potentially widespread pollutant.

(Photo: He Jiankui, Chinese scientist and professor at Southern University of Science and Technology in Shenzhen. Credit:Reuters)

Presenter: Roland Pease
Producer: Julian Siddle