Asked by: Richard Wainsley, King's Lynn

Snake venom is made by organs that evolved from salivary glands. Ordinary saliva contains enzymes to help digest food as you chew it and natural selection has favoured snakes that include ever more toxic enzymes in their saliva.

Scientists at Bangor University recently sequenced the genome of the king cobra and found that the toxins in its venom are slight variations of ordinary proteins. As prey gradually evolved immunity, so snakes have responded with a complex mix of 50-100 different proteins to alter blood pressure, prevent blood clotting and paralyse nerves.

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luis villazon
Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.