Saturday, April 27, 2013

Indirect Evidence of Panspermia?

From MIT Technology Review:
As life has evolved, its complexity has increased exponentially, just like Moore’s law. Now geneticists have extrapolated this trend backwards and found that by this measure, life is older than the Earth itself.

... is it reasonable to think that the complexity of life has increased at the same rate throughout Earth’s history? Perhaps the early steps in the origin of life created complexity much more quickly than evolution does now, which will allow the timescale to be squeezed into the lifespan of the Earth.

Sharov and Gorden reject this argument saying that it is suspiciously similar to arguments that squeeze the origin of life into the timespan outlined in the biblical Book of Genesis.

Let’s suppose for a minute that these guys are correct and ask about the implications of the idea. They say there is good evidence that bacterial spores can be rejuvenated after many millions of years, perhaps stored in ice.

They also point out that astronomers believe that the Sun formed from the remnants of an earlier star, so it would be no surprise that life from this period might be preserved in the gas, dust and ice clouds that remained. By this way of thinking, life on Earth is a continuation of a process that began many billions of years earlier around our star’s forerunner.

Sharov and Gordon say their interpretation also explains the Fermi paradox, which raises the question that if the universe is filled with intelligent life, why can’t we see evidence of it.

However, if life takes 10 billion years to evolve to the level of complexity associated with humans, then we may be among the first, if not the first, intelligent civilisation in our galaxy. And this is the reason why when we gaze into space, we do not yet see signs of other intelligent species.
Read the whole thing.

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