Over the past five years I’ve written several posts on the long-standing and vexing question, “Why on earth do zebras have stripes?” (See posts here, here and here.) If you’ve read those posts, you’ll know about the experiments that seemed to settle the issue, or at least that gave a good indication of the evolutionary forces that promoted the evolution of this striking pattern.
One clue is shown below: a figure from a paper that I described in an earlier post (my emphasis). The top part shows the distribution of various striped equids in Africa (the green and orange are unstriped Asian equids) and the bottom shows range maps of two groups of biting flies: tabanids (horseflies) and Glossina, the tsetse fly; both of these carry equine diseases and also promote infections and blood loss. As I wrote at the time (my emphasis):
Here’s the association between the historical (not present!)…
View original post 967 more words