Live birth has evolved independently more than 150 times. The underlying biophysical processes all look quite similar, but new research shows they use completely different genetic tools.
Males of most animal species die earlier than females because their smaller Y chromosome is unable to protect an unhealthy X chromosome, research suggests.
Once genetic lesions for diseases such as cystic fibrosis and haemophilia were identified, the idea of replacing or correcting defective genes grew into what we now call "gene therapy".
