"Looking from the astrobiology perspectives, life on Earth started early—just about as soon as it could. The more we learn about the origin of life, the more we realize it may be a likely outcome any time you have the right ingredients. However, if you look at the history of life on Earth, let’s say you put it on a twelve-hour clock, up until four o’clock it was just a world of microorganisms, from four to five o’clock that’s the era of plants coming onto land and animals and creatures in the sea, then after five o’clock until about ten o’clock this will be a world of only microorganisms again. So, in fact, our planet is in its late middle ages in terms of life on the surface. Then from ten o’clock until about midnight, the world will be completely desolate, devoid of life as the sun is running out of its nuclear fuel in the center and its outer atmosphere is expanding. The point is that our world has had big life for only a small slice of its existence and the portion of that which has had technology is even smaller. I think life is presumably abundant everywhere; the most common form is likely going to be microbial life. In addition, the distances are so vast that unless other civilizations have developed both a means of crossing those distances quickly and the desire to do so, plus the energy capability, I don’t know if we’ll see alien intelligence in our lifetime."