Thanks to that boring lecture on Charles Darwin in high school, most of us assume that giraffes’ long necks are to help them reach food in the tops of trees. Well, to be fair, this is indeed the most preferred hypotheses by scientists all around.
But a few scientists think the necks have more to do with something more basic – SEX.
Today’s Needull is an interesting 1996 research paper from The American Naturalist journal that I came across inadvertently.
Around 15 million years ago, antelope-like animals were roaming the dry grasslands of Africa. There was nothing very special about them, but some of their necks were a bit long. Within a mere 6 million years, they had evolved into animals that looked like modern giraffes, though the modern species only turned up around 1 million years ago. The tallest living land animal, a giraffe stands between 4.5 and 5 metres tall – and almost half that height is neck.
Most people assume that giraffes’ long necks evolved to help them feed. If you have a long neck, runs the argument, you can eat leaves on tall trees that your rivals can’t reach. But there is another possibility. The prodigious necks may have little to do with food, and everything to do with sex.
Disclaimer: The views in this paper are not accepted by all evolutionary biologists. Most still believe that giraffe necks are a result of the scarcity of food. The necks-for-sex hypothesis by Simmons and Scheepers remains highly contentious and there are also multiple published evidence for the competing-browsers hypothesis.
P.S: As suggested in comments by our reader WeggieBoy, ‘the notion of long necks evolving in giraffes is classically Lamarckian more than Darwinian’. The reason why I have mentioned Darwin is because that is exactly what is taught in most high schools.