I'm responding to Jacob Haqq-Milsra's question.
Jacob Haqq-Misra said...
I'm curious as to why you think the evolution of what we call intelligence is uncommon (if in fact this is what you mean)?
Of course, we cannot say anything for certain at this point, but I am inclined to think given the vast number of galaxies in the universe (100 billion) this type of complex life (however we define it) is probably present in some other galaxy--if not our own.
I do agree with you that there is a vast number of galaxies in the universe. I'm not ruling out any life on other planets.
I have read a few books about history of evolution. As you know, our planet started with very simple life about 2 billion years ago. The life didn't start to become complex until more than 550 million years. I'm inclined to support the Cambrian explosion theory. Before us, there were many millions of species and they didn't have intelligence that is similiar to ours.
When the apes started to evolve in Africa, they didn't have to compete that much. Africa was just an island. They had an advantage for some time. We can say that isolation has helped them. I am pretty sure that there are other species roaming in Africa during that time.
If there are species living on other worlds that have successfully become complex, they are likely to compete for food. It doesn't require any intelligence to do that. What's the odd of species becoming isolated from deadly predators? In my own opinion, it's pretty slim. Can species become lucky by developing hands that are more sophisticated? Can their brains get bigger and complex enough to bring them to the same level as ours, or even better?
The way I see, the process of evolution has to do with climate, sexual selection, geography, competition, and luck. Yes, I have to say that we are lucky that we are here today. It's like winning a lottery.
If we have to start all over again by going back to 2 billion years ago, will the apes ever emerge? I'm doubtful but I could be wrong. I will never know for sure.
One last thing, I wouldn't rule out any life out there that has intelligence like ours. If we ever find out by establishing communication with them or even meet them, I would be surprised and jubilant.
I'm open for any debate.m>