Intelligence: A Rare Cosmic Commodity?

Space.com

In a recent paper published in the journal Astrobiology, Professor Andrew Watson of the University of East Anglia describes an improved mathematical model for the evolution of intelligent life as the result of a small number of discrete steps.

According to Professor Watson, there evolution of intelligence is quite likely to be a rare phenomenon in our Galaxy.

He concludes this based on the additive probability of each of the steps occurring during the 4 billion years available for evolution. He feels these steps must occur in the proper sequence, also, and that they may irreversibly change the biosphere of the planet. For example, the evolution of plant life ended up changing the concentration of oxygen in our atmosphere.

The habitability of Earth is defined partly by the length of time that the sun will remain stable. As the Sun progresses, it will increase its temperature about 25%.

So if you calculate the additive probability of each major step that allowed the evolution of intelligence, according to Dr Watson, that ends up with a probability of less than 0.01% during the 4 billion years available.

Though a billion years is a long time, it's only a fraction of the time the planet exists, which makes the lifespan of an intelligent species somewhat limited.

Though there are some competing opinions, notably that of Seth Shostak, this new estimate puts a bit of a damper on the notions of the prevalence of intelligent life in our Galaxy.


[edit on 11-4-2008 by Badge01]

From the same article:


That was the first thing that crossed my mind as I read the article: how exactly did he project the odds? Our knowledge of the process of evolution is very limited, even to the point of not knowing for certainty whether it is the main force behind species change or a supplemental one.

And again, I mention my personal belief that any species intelligent enough to be capable of long-distance space travel would be too intelligent to come here. So how would we even be able to find them if they did exist? I know I would be hiding if I realized humanity was looking for me...

And even this scientist has made a possible error. What intelligent species was he referring to? Dolphins?

TheRedneck

I can imagine this is all true, I think life is probably very rare, at least any kind of sentient life anyway.

Then again, with so many star systems in the galaxy even 0.01% could mean many planets with life. I read somewhere that using a mathematical model it was predicted there would be 50 civilised races in our 'arm' of the spiral galaxy that would attain space travel and communications (and thus have potential for them to come into contact with us), but it was unknown how many would destroy themselves/eachother etc.

I think it's unlikely we're alone in the galaxy, definitely not the the whole universe, but yeah I think life is a pretty rare occurance as Watson suggests.