If you haven’t heard about the aptly nicknamed Hobbit, you should know about it. In 2003 a new species of human was excavated from a cave in Indonesia. Homo floresiensis was about 3 feet tall and had an incredibly small brain. This has been a point of some contention, and multiple genetic conditions have been proposed to be responsible for the specimen. A torrent of studies have fought over the details and interpretation of various proportions of the bones.
Despite the tiny brain, it was found with quite sophisticated stone technology. This could have been necessary to hunt the big game of the island. It is unclear whether it was of their species’ own merit or by human interaction. The fauna of the island would have included pygmy elephants, giant rats, and komodo dragons; and the island inhabitants lived at the same period as modern humans (94,000 to 13,000 y.a.). The scientific consensus is currently that this is a new species (not just an abnormal human), though the case will not be closed until a second specimen is discovered.
It really fascinates me that they had such a small brain, and yet seemed to have complex weapons and tools. I entertain the idea that complicated tools originated in this line and moved to human populations by mimicry. This is a neurological outrage for a number of respects. From the brain/body proportion, scientists would expect a dramatically hindered organism in mental faculties. Perhaps the species was far less socially intelligent than the majority of apes, and diverted more brainpower towards other means.