Who are you calling stupid?

Clusters of cells that are instrumental in building complex brains have been found in a simple worm that barely has a brain at all. The discovery suggests that, around 600 million years ago, primitive worms had the machinery to develop complex brains. They may even have had complex brains themselves - which were later lost. Vertebrates, such as humans and fish, have the biggest and most complex brains in the animal kingdom. Yet all their closest non-vertebrate relatives, such as the eel-like lancelets and sea squirts, have simple brains that lack the dozens of specialised nerve centres typical of complex brains. As a result, evolutionary biologists have long thought that complex brains only evolved after animals with backbones appeared.
  Not so, says Christopher Lowe of Stanford University in California.