EVIDENCE OF CONSTRAINED PHENOTYPIC EVOLUTION IN A CRYPTIC SPECIES COMPLEX OF AGAMID LIZARDS

Lineages that exhibit little morphological change over time provide a unique opportunity to explore whether nonadaptive or adaptive processes explain the conservation of morphology over evolutionary time scales. We provide the most comprehensive evaluation to date of the evolutionary processes leadi...

Full description

Saved in:
Bibliographic Details
Published in:Evolution 2011-04, Vol.65 (4), p.976-992
Main Authors: Smith, Katie L., Harmon, Luke J., Shoo, Luke P., Melville, Jane
Format: Article
Language:English
Subjects:
Agamidae
Animals
Base Sequence
Bayes Theorem
Biological Evolution
Biological taxonomies
Body Weights and Measures
Conservation
Datasets
Divergent evolution
DNA, Mitochondrial - genetics
Ecological genetics
Ecological modeling
Ecosystem
Evolution
Evolutionary genetics
Genes
Genes, RAG-1 - genetics
Genotype & phenotype
Geography
Likelihood Functions
Lizards
Lizards - anatomy & histology
Models, Biological
Molecular Sequence Data
morphological evolution
morphological stasis
nonadaptive
Northern Territory
Phenotype
Phylogenetics
Phylogeny
Queensland
Reptiles & amphibians
Sequence Analysis, DNA
Species Specificity
Western Australia
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Lineages that exhibit little morphological change over time provide a unique opportunity to explore whether nonadaptive or adaptive processes explain the conservation of morphology over evolutionary time scales. We provide the most comprehensive evaluation to date of the evolutionary processes leading to morphological similarity among species in a cryptic species complex, incorporating two agamid lizard species (Diporiphora magna and D. bilineata). Phylogenetic analysis of mitochondrial (ND2) and nuclear (RAG-1) gene regions revealed the existence of eight deeply divergent clades. Analysis of morphological data confirmed the presence of cryptic species among these clades. Alternative evolutionary hypotheses for the morphological similarity of species were tested using a combination of phylogenetic, morphological, and ecological data. Likelihood model testing of morphological data suggested a history of constrained phenotypic evolution where lineages have a tendency to return to their medial state, whereas ecological data showed support for both Brownian motion and constrained evolution. Thus, there was an overriding signature of constrained evolution influencing morphological divergence between clades. Our study illustrates the utility of using a combination of phylogenetic, morphological, and ecological data to investigate evolutionary mechanisms maintaining cryptic species.
ISSN:0014-3820
1558-5646
DOI:10.1111/j.1558-5646.2010.01211.x