http://www.newscientist.com: YOU know that you are conscious. Hopefully, you believe me when I tell you that I am, too. But is your pet dog or cat conscious? What about a tool-making crow, or a “clairvoyant” octopus or a worm? You might think it is impossible to find out. There is no distinctive pattern of brain activity that indicates consciousness, and we can’t exactly ask animals about their experiences. We don’t even fully understand what consciousness is.
But maybe there’s a way to get a handle on it. What if we tracked consciousness to its origins? Then, instead of asking what consciousness is, we ask why it evolved – in other words, what is it for? Until recently, that question has been largely ignored. But now biologists are starting to feel their way around the tree of life to consider where, when and why something resembling consciousness emerged. Their research is proving surprisingly fruitful. It’s not just shedding light on animal minds, it is also providing insights into the very nature of consciousness.