The Star Trek fans among you are no doubt familiar with “The Menagerie,” a two-episode story from the first season in 1966. The crew of the Enterprise gets trapped on a planet occupied by aliens called Talosions who look like humans, except for their massive, vein-encircled brains.*

That story was produced the year I was born, and when I saw it about a decade later, it made a big impression on me. Could brains get that big? Would they wind up with that cantaloupe shape? Would they provide Talosians with super-intelligence?

My ten-year-old brain was too underdeveloped to process the paradox that these were aliens living on another planet–and therefore would have likely followed an unimaginably different route of evolution. Chances