Wednesday, October 17, 2012

On the evolution of intelligence

We are fascinated by the question of where our intelligence arose, and how our ancestors transitioned from clever apes to humans with big brains imparting the capacity for abstract thought and a life of the mind. This week, real life intersected with WoW life and I have been thinking on this specific question and the more general question of how large brains and complex behavioral repertoires have arisen in a number of lineages spanning nearly every major branch of the animals. In Azeroth, we know of one driving force that has the ability of "elevating" a species to a higher level of intelligence, which manifests as the ability to use magic to shape the world. That force is the Well of Eternity.

From JadedAlt, because I don't have any screenshots of my own!

The Well of Eternity is a font of magical waters that drove the physical and magical evolution of the night elves from troll-like ancestors. The silithids were also affected by the Well, although not to the extent of the kaldorei. Now that we have arrived in Pandaria, we have learned that the Mogu also arose from humble beginnings, reaching great intellectual and magical heights due to their interaction with the waters of the Vale of Eternal Blossoms. It would appear that a second source of the Well of Eternity exists in Pandaria. The Well was put upon Azeroth by the Titans, a race of god-like world creators, for reasons unknown.

A sentient race placing an object on a planet to drive the evolution of intelligence in its creatures? A familiar theme in science fiction as well, such as Arthur C Clarke's 2001.

The religions of earth have of course adopted a similar approach to the question of the origin of intelligence, but invoking an omniscient god to infuse the first humans with intelligence or to provide a guiding hand to facilitate its evolution.

In my business, evolutionary neurobiology, we look for driving forces, selective pressures, here on earth. The consensus at the moment is that environments that provided cognitive challenges drive the evolution of behaviors to deal with them, and the large brains needed to support those behaviors. The question that is most difficult to solve is what would be that cognitive challenge. In insects, my model species, the need for visual cognition: learning and associating visual cues, and learning to orient in a larger world using visual landmarks, is associated with the acquisition of large higher brain centers in at least three separate groups of insects (the ants bees and wasps, the cockroaches, and herbivorous scarab beetles). In vertebrates, the cognitive demands of social living are often invoked, but this may not hold up outside of our species.

From link

Whatever those selective pressures were, they had a rapid and dramatic effect on brain size in a number of animal lineages. The above graph shows just how dramatic: after a period of relative stasis in brain size, hominid brains expanded rapidly beginning about 2 million years ago. Similar trends are seen in cetaceans (whales and dolphins) and elephants, as well as in the insect group Hymenoptera (wasps of all kinds, as well as ants and bees).

Something here on earth is providing a Well of Eternity-like selective pressure to some of our creatures, resulting in rapidly increasing brain sizes, expanding behavioral repertoires, and in the case of humans, the evolution of sentience. One of my primary goals as a scientist is to gain a better understanding of what that might be, using the endless diversity of insects to give clues as to what behavioral capabilities might have provided such an enormous selective advantage that they warranted a greatly increased investment in energetically expensive brain tissue. And since evolution tends to take similar paths even in distantly related species, it's likely that insights provided by insects will shed light on the evolution of brain and behavior in vertebrates and even humans.


  1. I love this post - science RULES!

  2. I've read this post three times and love it more each time I read it!

  3. I want to write a science-y post about what a good job Blizz has done with insects in this expansion- bugs everywhere!

  4. neandertal brain