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dc.contributor.author Martin, Christopher Herbert
dc.coverage.spatial Cameroon
dc.coverage.spatial Lake Ejagham
dc.coverage.spatial Lake Barombi Mbo
dc.coverage.spatial Kumba
dc.coverage.spatial Eyumojock
dc.date.accessioned 2012-05-16T17:25:26Z
dc.date.available 2012-09-25T17:44:07Z
dc.date.issued 2012-08-24
dc.identifier doi:10.5061/dryad.rn30d
dc.identifier.citation Martin CH (2012) Weak disruptive selection and incomplete phenotypic divergence in two classic examples of sympatric speciation: Cameroon crater lake cichlids. American Naturalist 180(4): E90-E109.
dc.identifier.uri http://hdl.handle.net/10255/dryad.39751
dc.description Recent documentation of a few compelling examples of sympatric speciation led to a proliferation of theoretical models. Unfortunately, plausible examples from nature have rarely been used to test model predictions, such as the initial presence of strong disruptive selection. Here I estimated the form and strength of selection in two classic examples of sympatric speciation: radiations of Cameroon cichlids restricted to lakes Barombi Mbo and Ejagham. I measured five functional traits and relative growth rates in over 500 individuals within incipient species complexes from each lake. Disruptive selection was prevalent in both groups on single and multivariate trait axes, but weak relative to stabilizing selection on other traits and most published estimates of disruptive selection. Furthermore, despite genetic structure, assortative mating, and bimodal species-diagnostic coloration, trait distributions were unimodal in both species complexes, indicating the earliest stages of speciation. Long waiting times or incomplete sympatric speciation may result when disruptive selection is initially weak. Alternatively, I present evidence of additional constraints in both species complexes, including weak linkage between coloration and morphology, reduced morphological variance aligned with nonlinear selection surfaces, and minimal ecological divergence. While other species within these radiations show complete phenotypic separation, morphological and ecological divergence in these species complexes may be slow or incomplete outside optimal parameter ranges, in contrast to rapid divergence of their sexual coloration.
dc.relation.haspart doi:10.5061/dryad.rn30d/1
dc.relation.haspart doi:10.5061/dryad.rn30d/2
dc.relation.isreferencedby doi:10.1086/667586
dc.relation.isreferencedby PMID:22976018
dc.subject Adaptive radiation
dc.subject Selection: natural
dc.subject Speciation: sympatric
dc.subject Fish
dc.subject disruptive selection
dc.subject nonlinear selection
dc.subject phenotypic variance-covariance matrix
dc.subject African cichlids
dc.title Data from: Weak disruptive selection and incomplete phenotypic divergence in two classic examples of sympatric speciation: Cameroon crater lake cichlids
dc.type Article *
dwc.ScientificName Tilapia ejagham
dwc.ScientificName Tilapia fusiforme
dwc.ScientificName Tilapia deckerti
dwc.ScientificName Stomatepia pindu
dwc.ScientificName Stomatepia mariae
dwc.ScientificName Stomatepia mongo
dwc.ScientificName Pungu maclareni
dc.contributor.correspondingAuthor Martin, Christopher Herbert
prism.publicationName The American Naturalist
dc.audience.educationLevel Martin CH (2012) Weak disruptive selection and incomplete phenotypic divergence in two classic examples of sympatric speciation: Cameroon crater lake cichlids. American Naturalist, 180(4) E90-E109.

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Title complete dataset
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Description Field data on fitness (growth rates estimated from scale circuli spacing), standard length, five morphological traits, species-diagnostic coloration, and stable isotope ratios for two species complexes of Cameroon cichlids: Barombi Mbo Stomatepia and Ejagham Tilapia.
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Title standardized and size-corrected fitness and trait data
Downloaded 64 times
Description Standardized and size-corrected estimates of fitness and five morphological traits used for measuring selection on two species complexes of Cameroon cichlids: Barombi Mbo Stomatepia and Ejagham Tilapia.
Download standardized and size-corrected fitness a...ta.zip (41.23 Kb)
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