Thursday, November 5, 2009

The Neck of the Giraffe


So after we watched a video of two male giraffes fighting (check it out here on youtube), we discussed the fact that the neck of the giraffe is elongated not in order to increase feeding efficiency, but rather to be better equipped to fight. Turns out that giraffes generally spend most of their time feeding at about 60% of their total height. So the long neck of the giraffe did not evolve because of any feeding benefit (after all, it would be easier to elongate the legs), but rather because of the need for males to fight over females or territory. Further, the neck may be subject to sexual selection (females chosing males with longer necks as an indication of health, fitness, etc.) in much the same way that the tail of a peacock is.
If you're interested in checking out a paper I wrote on the subject of the evolution of the giraffe's neck, check this out: Whence the Long Neck?

We went on to discuss the fact that a giraffe must work terribly hard to get blood from its heart to its head, a trip that is often on the order of two meters. If you're really curious about how it happens, check out this paper (that I also wrote!): On the Hemodynamics of Long Necks

Can you think of any other animals where it might be difficult to move blood around? Post a comment if you can!

1 comment:

Chad DeVoe said...

That Youtube video is out of control.