Paleolimnological History of the Coorong: Identifying the Natural Ecological Character of a Ramsar Wetland in Crisis

The Geography of Speciation and Character Displacement

Phylogenies in Ecology ◽

10.23943/princeton/9780691157689.003.0006 ◽

2016 ◽

Author(s):

Marc W. Cadotte ◽

T. Jonathan Davies

Keyword(s):

Species Interactions ◽

Character Displacement ◽

Species Traits ◽

Dispersal Ability ◽

Resource Base ◽

Sympatric Populations ◽

Ecological Character ◽

Ecological Character Displacement ◽

History Of ◽

Antagonistic Interactions

This chapter examines how phylogenetic approaches can address both ecological character displacement and community-wide character displacement. In ecological character displacement, selection might drive the divergence of ecological phenotypes by negative antagonistic interactions that reduce competition between sympatric populations utilizing the same resource base. In community-wide character displacement, ecological divergence occurs in allopatry, and competition filters species into communities based upon their trait values. The geographic distribution of a species reflects multiple factors, including its strength of phylogenetic niche conservatism and the geography of present day climate, its dispersal ability, and the history of speciation. This chapter considers the effect of competition in the native range, focusing on a scenario in which the evolution of species traits may itself be a product of species interactions. It shows that phylogenetic methods can additionally provide insights into how species interactions might shape trait evolution and even illuminate the process of speciation itself.

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Testing limiting similarity in Quaternary terrestrial gastropods

Paleobiology ◽

10.1666/07058.1 ◽

2008 ◽

Vol 34 (3) ◽

pp. 378-388 ◽

Cited By ~ 17

Author(s):

John Warren Huntley ◽

Yurena Yanes ◽

Michał Kowalewski ◽

Carolina Castillo ◽

Antonio Delgado-Huertas ◽

...

Keyword(s):

Body Size ◽

Late Quaternary ◽

Evolutionary Process ◽

Character Displacement ◽

Land Snails ◽

Limiting Similarity ◽

Similar Species ◽

Ecological Character ◽

Ecological Character Displacement ◽

History Of

The hypothesis of limiting similarity, which postulates that morphologically and/or ecologically similar species will differ enough in shape, size, or other variables to minimize competition, has been controversial among ecologists and paleoecologists. Many studies have reported the occurrence of limiting similarity in modern environments or in time-averaged fossil deposits; however, empirical high-resolution time series demonstrating limiting similarity over longer time scales are lacking. We have integrated radiocarbon-calibrated amino acid dating techniques, stable isotope estimates, and morphometric data to test the hypothesis of limiting similarity in late Quaternary land snails from the Canary Islands over a period of 42,500 years. We tested for both ecological character displacement (two closely related species will differ in size in order to minimize competition in sympatry and these differences will be minimized in allopatry) and communitywide character displacement (overdispersion of body size among competitors in a guild). Multiple proxies of body size consistently show that two endemic congeneric pulmonate gastropod species (Theba geminata and T. arinagae) maintained a difference in size from ~42,500 B.P. through the last occurrence of T. arinagae 14,900 B.P., with a concomitant trend of a decreasing body size. Theba geminata body size did not converge on that of T. arinagae and variation in T. geminata body size did not increase significantly following the extinction of T. arinagae; therefore, ecological character displacement and release did not occur. Community-wide character displacement was found in only one time bin over the last 42,500 years. These results suggest that limiting similarity is a transient ecological phenomenon rather than a long-term evolutionary process. This study not only demonstrates the problems inherent in biological “snapshot” studies and geological studies of time-averaged deposits to test limiting similarity adequately, but it also presents a more adequate research protocol to test the importance of interspecific competition in the history of life.

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