Tuesday, December 27, 2011

It's Lonely Out There The Evolutionary Explanation For The Fermi Paradox - John Lambshead

"Humans have key characteristics other than size. We are tetrapods that are obligatory bipeds so we had the possibility to evolve hands. This is unique among mammals and reflects our unusual evolutionary journey from the trees to the plains of Africa. This change of habitat is somewhat unusual and seems to have been driven by climate instability causing rapid retreat and advance of woodland.

We have forward facing "predator" eyes, our primary sense is sight, and good hand-eye coordination – again an evolutionary hangover from an earlier arboreal existence.

Most mammals are primarily smell and sound orientated but vision is our primary sense and we use sound near exclusively to communicate, our secondary method being visual. We can make a wide variety of noises so can exchange sophisticated abstract concepts. None of this guarantees intelligence. It merely allows it to develop. For example, birds have many of these features, a sophisticated high-energy metabolism, good vision and complex vocal and visual communication but they are small, having lost out in the competition with mammals to exploit large-body ecological niches. Large non-flying birds did evolve on isolated islands but had no potential for the evolution of hands. Wings are so specialised that it is difficult to see how they could evolve into hands. Evolution is difficult to reverse.

Therapod dinosaurs, birds' close relatives, developed all the physical bodily prerequisites for the evolution of intelligence since they had bird-like characteristics but, being non-flying, could be large and had the potential for the evolution of hands. Feathers did not evolve for flight but as a component of a high-energy sophisticated metabolism and a number of therapods were feathered. So why did an intelligent therapod not evolve?"

4 out of 5