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Record W1978611425 · doi:10.1086/303412

Ecological Character Displacement in Adaptive Radiation

2000· article· en· W1978611425 on OpenAlex
Dolph Schluter

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
fundA Canadian funder is recorded on the work.

Bibliographic record

VenueThe American Naturalist · 2000
Typearticle
Languageen
FieldEnvironmental Science
TopicEcology and Vegetation Dynamics Studies
Canadian institutionsUniversity of British Columbia
FundersNatural Sciences and Engineering Research Council of Canada
KeywordsCharacter displacementSympatryAdaptive radiationCompetition (biology)EcologySympatric speciationInterspecific competitionTrophic levelBiologyComplementarity (molecular biology)Divergence (linguistics)Phylogenetic tree

Abstract

fetched live from OpenAlex

I give an overview of the observational and experimental evidence for ecological character displacement in adaptive radiation. Sixty‐one published cases of character displacement involving closely related species (congeners) make up the observational data set. All cases involve divergence, even though parallel and convergent displacement are theoretically possible. Character ratios in sympatry were greatest when displacement was symmetric (mean 1.54) and least when asymmetric (mean 1.29), perhaps because the most symmetric resource distributions are also the broadest. Carnivores are vastly overrepresented in the data compared with other trophic groups, with herbivores the next most common category. I consider five hypotheses to explain this pattern, including the possibility that the likelihood of divergence via competition depends on position in food webs. Overall, the quality and completeness of observational data has improved in recent years, as judged by the extent to which individual cases satisfy six standard criteria. All but one of the criteria are met in over half the cases. Most often lacking is independent evidence that the species involved compete for resources. For this reason, we cannot be sure that divergence in sympatry is usually the result of resource competition rather than some other interaction. Field experiments on character displacement, which explore how interaction strength changes per unit change in phenotypic traits, are only just beginning. I summarize research on threespine sticklebacks that used experiments in ponds to test three predictions: that present‐day differences between sympatric species are a “ghost” of competition past; that adding a competitor alters natural selection pressures on a species already present, favoring divergence; and that divergent natural selection stemming from resource competition is frequency dependent. In total, the evidence suggests that character displacement occurs frequently in nature, and it probably plays an important role in the evolution of diversity in many adaptive radiations.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesInsufficient payload (model declined to judge)
Consensus categoriesInsufficient payload (model declined to judge)
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.165
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0030.001

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.006
GPT teacher head0.238
Teacher spread0.231 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it