The Steinhardt Museum of Natural History, Tel Aviv University, Tel Aviv 6997801, Israel
Background/Question/Methods Ecological character displacement implies increased differences of size in sympatry between closely-related or ecologically similar species, a pattern attributed to the selective force of interspecific competition. A related concept is community-wide character displacement, implying overdispersed size patterns among potential competitors within ecological guilds. These theories were at the heart of a major debate, sparked by Dan Simberloff’s critical appraisal of earlier work, regarding the role of competition in structuring ecological guilds and communities. This debate was also significant to understanding the evolution of body size patterns, a key characteristic of animal biology and to the existence (or lack thereof) of recurrent morphological patterns in island communities. Mostly, it was about the existence of general rules in the amazing complexity of ecological communities.
Results/Conclusions Simberloff’s critical approach and the ensuing debate heralded a new generation of rigorous, critical studies of ecological communities using robust statistical tools. The reappraisal of guilds as building blocks of ecological communities, use of sound statistics to test for the occurrence of character displacement in a wide variety of taxa, incorporating approaches of functional morphology and actual tests of morphologically related resource partitioning – all contributed to our understanding of the structure of ecological communities, and provided scientifically rigorous support for recurring patterns of ecological character displacement and community-wide character displacement and the role of competition in structuring ecological communities. The evidence of the structuring force of inter- and intraspecific competition contributed to the interpretation of temporal patterns in body size evolution, to understanding macroecological patterns, and to the search of generalities in complex ecological communities, and yet many more questions remain to be studied in this arena. Studying the role of the diel niche axis in competition within ecological communities, its role in structuring ecological communities and in driving the evolution of activity patterns, was the next logical scientific step, and that too still provides many exciting research avenues to be explored.