Does life have a purpose?
Nobody expects atoms and molecules to have purposes, so why do we still think of living things in this way?
One of my favorite dinosaurs is the Stegosaurus, a monster from the late Jurassic (150 million years ago), noteworthy because of the diamond-like plates all the way down its back. Since this animal was discovered in the late 1870s in Wyoming, huge amounts of ink have been spilt trying to puzzle out the reason for the plates. The obvious explanation, that they are used for fighting or defence, simply cannot be true. The connection between the plates and the main body is way too fragile to function effectively in a battle to the death. Another explanation is that, like the stag’s antlers or the peacock’s tail, they play some sort of role in the mating game. Señor Stegosaurus with the best plates gets the harem and the other males have to do without. Unfortunately for this hypothesis, the females had the plates too, so that cannot be the explanation either. My favourite idea is that the plates were like the fins you find in electric-producing cooling towers: they were for heat transfer. In the cool of the morning, as the sun came up, they helped the animal to heat up quickly. In the middle of the day, especially when the vegetation consumed by the Stegosaurus was fermenting away in its belly, the plates would have helped to catch the wind and get rid of excess heat. A superb adaptation. (Sadly for me, no longer a favoured explanation, since latest investigations suggest that the plates may have been a way for individuals to recognise each other as members of the same species).
READ OF THE DAY… keep on reading