The nature and origins of consciousness are still a hot topic for cognitive scientists, roboticists, and other researchers. Rodrick Wallace and Roger G. Wallace explore the idea that evolutionary history may be littered with the "fossils" of consciousness. The propose that consciousness is an example of evolutionary convergence in a new draft of their paper, Darwin's rainbow: Evolutionary radiation and the spectrum of consciousness (PDF format). Simply put, convergence refers to the concept that evolution may follow different paths in different species yet arrive at the same destination. They propose that animals with "rapidly shifting, sometimes highly tunable, temporary assemblages of interacting unconscious cognitive modules" exhibit behaviors we recognize as consciousness. They also propose that a mathematically similar phenomenon occurs over much large timescales. They call this slower process paraconsciousness. Though a little math heavy at times, the paper is an interesting read.