According to MSNBC today, astrobiologist Milan Cirkovic thinks we should look at younger stars as well as older ones for intelligent life, reasoning that it might not take 4.5 billion years, as it did on Earth, to arrive at an intelligent species. Cirkovic’s theory is that a planet’s life clock, via catastrophc events, can be reset numerous times throughout its history, and thus an intelligent species might arise between these events more quickly on some stars than on others. On Earth, for example, the comet that killed off the dinosaurs reset Earth’s life clock for a fresh round of global speciation, and ended up generating humans just 65 million years later. In other words, some planets may have hit the combination of multicellular life to intelligent life much quicker than Earth did, for really Earth only required 65 million years to do it (not 4.5 billion years). What this means is that there might be relatively young stars with relatively young planets that have civilizations on them more advanced than our own, and that evolved to their advanced states within, say, 65 million years after large, multicellular life forms appeared generally.
“The speed of evolution is very variable,” Cirkovic said. . . . Cirkovic also notes that the evolution of intelligent life could occur slower or faster in different settings, and need not follow the astrobiological history of the Milky Way. “Large-scale correlations might cause more such SETI targets to be contemporary with us than would be expected on the basis of planetary age distribution only,” Cirkovic said.
In other words, Cirkovic’s new theory is that we should be looking for intelligent life, not just in solar systems of our own age, but in newer ones as well. This means for astrobiologists a larger pool of search targets. We shouldn’t assume, according to Cirkovic, that a two billion year old solar system hasn’t had enough time to get to intelligent life yet. It may well be ahead of us!
Prometheus Unbound 