[onedoug]

...including speculations that life might have been seeded on Earth as part of an experiment by aliens.

Even accomplished scientists can often be nuts.

[armydoc]

Even accomplished scientists can often be nuts.

Actually, Crick's advocacy of "panspermia" was his most logical move, given that his world view would not allow creationist alternatives. Crick was indeed intelligent; when the incredible complexity of even the simplest living cell was shown shortly after his DNA discovery, he realized that spontaneous generation was just not plausible. Panspermia was the next logical alternative, though in the end it just pushes off the necessity of spontaneous generation to another time/place.