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Abstract Closely related species can impose strong forces of selection on one another through competition, leading to dramatic examples of phenotypic evolution. Niche partitioning can promote the use of novel resources between co-occurring species to reduce competitive overlap and thereby drive phenotypic divergence. Quantifying this potential relationship between ecology and morphology among species can reveal how opportunity and constraint interact to shape patterns of phenotypic evolution and how phenotypic diversity can facilitate co-occurrence. We explored the dynamics of ecomorphological evolution in relation to speciation and co-occurrence in Sceloporus lizards, a speciose group spanning North and Central America, where species often occur in sympatry. We collected data for 80 species and demonstrated strong relationships between multivariate morphology and ecology, finding that Sceloporus species occur in six ecological modes with associated morphologies (ecomorphs). The evolution of arboreality was a major transition that expanded morphospace, allowed for the evolution of further ecological novelty, and is associated with increased speciation rates. Across their range, Sceloporus ecomorphs are spatially overdispersed, suggesting that interspecific competition may limit the ability of similar species to coexist. By quantifying ecomorphological diversity across a diverse radiation, our results shed new light on how phenotypic variation accumulates and its implications for coexistence between closely related species.
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When Does Form Reflect Function? Acknowledging and Supporting Ecomorphological Assumptions
Abstract Ecomorphology is the study of relationships between organismal morphology and ecology. As such, it is the only way to determine if morphometric data can be used as an informative proxy for ecological variables of interest. To achieve this goal, ecomorphology often depends on, or directly tests, assumptions about the nature of the relationships among morphology, performance, and ecology. We discuss three approaches to the study of ecomorphology: morphometry-driven, function-driven, and ecology-driven and study design choices inherent to each approach. We also identify 10 assumptions that underlie ecomorphological research: 4 of these are central to all ecomorphological studies and the remaining 6 are variably applicable to some of the specific approaches described above. We discuss how these assumptions may impact ecomorphological studies and affect the interpretation of their findings. We also point out some limitations of ecomorphological studies, and highlight some ways by which we can strengthen, validate, or eliminate systematic assumptions.
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- PAR ID:
- 10112439
- Date Published:
- Journal Name:
- Integrative and Comparative Biology
- Volume:
- 59
- Issue:
- 2
- ISSN:
- 1540-7063
- Page Range / eLocation ID:
- 358 to 370
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1093/icb/icz070
