There's a danger of some of the best people saying, 'I don't want a career in science.'

The earliest example known to me of replaced body parts is exemplified by a Mayan skull dating back to 1400 BC. In this skull, false teeth made of stone had been implanted.

The earliest example known to me of replaced body parts is exemplified by a Mayan skull dating back to 1400 BC. In this skull, false teeth made of stone had been implanted.