-------- Original Message -------- Subject: allometry in genitalia Date: Mon, 24 Nov 2008 11:55:42 -0800 (PST) From: Elen Oneal <[EMAIL PROTECTED]> To: [email protected] Hi, I am studying the evolution of genitalia shape in a species of cricket, Amphiacusta sanctaecrucis. I have found evidence that divergence in genitalia shape is the result of directional selection, however, other authors suggest that variation in genitalia shape is the result of stabilizing selection-- a sort of "one size fits all" hypothesis. I would like to test for an allometric relationship between genitalia size and overall body size. I took all my pictures at the same magnification with the same scope, but did not include a scale. Can I still regress the centroid size on femur length (as a substitute for body size) and use the residuals as measures of genitalia size? I have been told that because I took my pictures in sand, variation in the placement of the genitalia may affect my measures of size. Thank you in advance, Elen Oneal ***************************************** Elen Oneal Ph.D. Candidate University of Michigan Dept. of Ecology and Evolutionary Biology Museum of Zoology Ann Arbor, Michigan 48109 (734) 763-7943 -- Replies will be sent to the list. For more information visit http://www.morphometrics.org
