In science, even self-evident truths need to be put to the test. There was an interesting story in the Telegraph last week, which described how scientists have tried to show that the long necks of giraffes are adaptations to give them an advantage over shorter animals when grazing trees. Bleeding obvious, you might think, but it has also been suggested that giraffes' long necks might be a result of sexual selection. Although the scientists concede that their experiment is not definitive, they conclude that giraffes browse at high levels in the leaf canopy out of preference (to avoid competition with shorter browsers), rather than simply because their necks happen to be long.
A small victory for common sense, then.
My first lesson in giraffe evolution occurred when I was about six years old. My primary school teacher explained to the class how giraffes tried to stretch their necks to reach the higher leaves and, over time, all giraffes ended up with longer necks. Little did I realise at the time that I was being taught a Lamarckian version of evolution. I'm sure this was not a deliberate mistake on my teacher's behalf: she probably thought she was introducing us to Darwinian thinking.
Come to think of it, that was the only lesson I ever received in evolution at either primary or secondary school. English school biology in my day was all about the organs of species, not their origins. I wonder if it has changed much.
