Of course, it’s even more unlikely to have all just happened by chance a number of times than just once. Nonetheless, New Scientist tries valiantly to ascribe it all to natural selection (acting on random mutation).
Snake species didn’t necessarily evolve venom by a long, slow, process of natural selection acting on random mutations (Darwinism). Some get their venom from a variety of sources and sometimes they change sources (whatever works?) So unfolds a curious tale of a snake that switched suppliers.