Emily H Kay1, Hopi E Hoekstra2. 1. Department of Organismic and Evolutionary Biology and The Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 02138, USA. Electronic address: ekay@oeb.harvard.edu. 2. Department of Organismic and Evolutionary Biology and The Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 02138, USA. Electronic address: hoekstra@oeb.harvard.edu.