Meeting Abstract

9.6  Monday, Jan. 4  The macroecology of rapid adaptive radiation PARNELL, N F*; STREELMAN, J T; Georgia Tech gth877n@mail.gatech.edu

A long-standing topic in ecology addresses whether natural communities are the result of stochastic factors or if assembly rules generate community structure. Non-random communities have been attributed to species interactions and more specifically competition – a driving force in adaptive radiations. Here we examine the macroecology of the recently radiated cichlid fish assemblage in Lake Malawi, Africa at a spectrum of increasingly fine spatial scales. Cichlid communities were not different from random until examined at the finest resolution (depth within sites) where a strong signal of community structure was evident. An analysis of pair-wise interactions among a ‘core’ group of cichlids revealed repeated patterns indicative of interspecific interactions as structuring mechanisms. Targeting a highly diverse and rapidly radiating assemblage for this analysis provides insights into how community structure emerges at different spatial scales and lends credence to the importance of fine-scale species interactions in community assembly.