Last night I half-watched the programme on TVOne about swarms. (I say half-watched because I was mostly listening to it while doing the washing up). It is certainly fascinating how large groups of fairly simply behaving creatures can have a 'group intelligence.' This kind of organization of small units into a larger entity is well studied in physics. Ants are particularly fascinating - an individual ant doesn't possess a great deal of intellectual capacity, but a whole colony seems to have some extra intelligence of its own. At one point the programme compared an individual ant to a brain cell, and the whole colony to a brain. Like single ants, brain cells on their own aren't particularly complicated systems - you can describe them with just a few equations (I know - I do that in some of my research). Basically if you poke them with enough current they 'fire', and if two cells that touch through a synapse fire at commensurate times, they can either strengthen or weaken that synapse between them. They can also 'leak' a bit of current from one cell to a neighbour. All very simple really. But stick lots together and you have a brain. (It could be your brain).
But here's where we get a problem with the analogy - we humans are conscious (for 16 hours a day, give or take) - I know I am as I write this, and I assume you are as you read it. But can a colony of ants be conscious? I find it hard to believe. What would that mean for the ethics of putting down poison to kill off the colony that's taken up residence in your house? Are you killing a being with a high-level of consciousness? Here's the problem for neuroscientists - what is it about the collection of cells in your brain that results in consciousness? Basically no-one has a clue. There are some ideas discussed, but getting any scientific evidence is going to be tricky. We can certainly say things like how consciousness correlates to the pattern of firing activity, for example the voltages picked up on the electroencephalogram (electrodes stuck on the scalp), and anaesthetists will often use the electroencephalogram to give them clues as to whether a patient is actually unconscious, but what is it about these firing events that leads to consciousness? Or what is it about consciousness that leads to those firing events? Or what is the unknown process that influences both the firing of cells and consciousness? I don't know.
What I'm saying here, is that consciousness isn't necessarily just a by-product of throwing lots of interacting brain cells together and so we should be a bit careful about saying a colony of interacting ants is 'intelligent', if that means we get the picture that there is some conscious thinking related to the colony.
The Blue Brain project, based at Lausanne in Switzerland, is (in simple terms) an attempt to simulate an entire region of a rat brain on a computer. The idea is that the computer simulation will respond in the same way as the rat brain. But will the computer simulation be conscious? I wouldn't think so.
As another example, think of plants. My colleague Alison Campbell has described some 'intelligent' (and quite surprising) plant behaviour. Plants that hunt, plants that communicate with others. Sounds like the triffids are already here.