Morphometrics and systematics

Zelditch, Miriam Leah; Swiderski, Donald L.; Sheets, H. David; Fink, William L.

doi:10.1016/b978-012778460-1/50016-8

Cited by 331 publications

(595 citation statements)

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“…The light gray boxes are 95% quantiles of mean pair-wise distance based on 1,000 bootstraps. Asterisks represent significant shifts in disparity, based on resampling tests with 1,000 bootstraps (P < 0.05, Bonferroni-corrected) (46). The dark gray vertical lines represent the following extinction events: the first Hirnantian extinction pulse at the onset of glaciation, the second Hirnantian extinction pulse as the glacial interval ended, and the extinction event at the end of the AZE in the Early Silurian.…”

Section: Resultsmentioning

confidence: 99%

Graptoloid diversity and disparity became decoupled during the Ordovician mass extinction

Bapst

Bullock

Melchin

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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The morphological study of extinct taxa allows for analysis of a diverse set of macroevolutionary hypotheses, including testing for change in the magnitude of morphological divergence, extinction selectivity on form, and the ecological context of radiations. Late Ordovician graptoloids experienced a phylogenetic bottleneck at the Hirnantian mass extinction (∼445 Ma), when a major clade of graptoloids was driven to extinction while another clade simultaneously radiated. In this study, we developed a dataset of 49 ecologically relevant characters for 183 species with which we tested two main hypotheses: (i) could the biased survival of one graptoloid clade over another have resulted from morphological selectivity alone and (ii) are the temporal patterns of morphological disparity and innovation during the recovery consistent with an interpretation as an adaptive radiation resulting from ecological release? We find that a general model of morphological selectivity has a low probability of producing the observed pattern of taxonomic selectivity. Contrary to predictions from theory on adaptive radiations and ecological speciation, changes in disparity and species richness are uncoupled. We also find that the early recovery is unexpectedly characterized by relatively low morphological disparity and innovation, despite also being an interval of elevated speciation. Because it is necessary to invoke factors other than ecology to explain the graptoloid recovery, more complex models may be needed to explain recovery dynamics after mass extinctions.M ass extinction events are defined by their effect on taxonomic diversity, but they also have profound impacts on the biotic diversity of morphology and ecology (1-3). Quantitative assessments of morphological diversity, i.e., disparity, can shed light on the selectivity of extinction and add to our understanding of the ecological context of recovery patterns after extinction events (4,5).In this paper, we quantify the morphological dynamics of the Graptoloidea during the end-Ordovician mass extinction, which began ∼445 million years ago. This event is composed of two separate extinction episodes during the Hirnantian Stage (6) and is commonly referred to as the Hirnantian mass extinction (HME). These episodes of increased extinction rate are associated with the initiation and termination of a global cooling period in the first half of the Hirnantian, during which sea-surface temperatures dropped ∼5°C (7, 8).Graptoloids are an extinct clade of colonial zooplankton (Hemichordata) noted for their well-sampled fossil record and high rate of species turnover (9-11). Previous work on the effect of the HME on the Graptoloidea has revealed a tumultuous and complex pattern. The graptoloids experienced some of the highest extinction intensities among marine invertebrates during the HME (12), and the surviving taxa were a limited sample of pre-HME lineages. Before the mass extinction event, graptoloid lineages can be divided into two monophyletic clades that diverged more than 20 million...

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Section: Resultsmentioning

confidence: 99%

Graptoloid diversity and disparity became decoupled during the Ordovician mass extinction

Bapst

Bullock

Melchin

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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“…The failure of all mtDNA haplotype lineages within P. blainvillii to coalesce between T1 and the present results in an opportunity for deep coalescence between P. blainvillii and P. cerroense. specimen using CoordGen (20). We used PCA to determine whether any morphological groupings were detectable without the a priori designation of groups, and we tested for significant differences in cranial horn shapes between parapatric phylogeographic groups using a 1-way MANOVA in JMP 7.0 (SAS).…”

Section: Methodsmentioning

confidence: 99%

“…Linear measurements of cranial horns were included in this study; however, standard linear measurements are limited to detecting changes in relative length and do not capture the extent to which complex shapes, such as curved cranial horns, vary among popu-lations. Geometric morphometric techniques provide a viable alternative for analyzing complex shapes in multivariate space by retaining information about the relative spatial arrangements of the data throughout the analysis, which allows for the visualization of shape differences among groups (20). In this study, we conduct a geometric morphometric analysis of cranial horn shapes to determine whether the morphological evolution of these characters accompanies the formation of lineages in the P. coronatum species complex.…”

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confidence: 99%

Quantifying ecological, morphological, and genetic variation to delimit species in the coast horned lizard species complex ( Phrynosoma )

Leaché

Koo

Spencer

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

208

160

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Lineage separation and divergence form a temporally extended process whereby populations may diverge genetically, morphologically, or ecologically, and these contingent properties of species provide the operational criteria necessary for species delimitation. We inferred the historical process of lineage formation in the coast horned lizard (Phrynosoma coronatum) species complex by evaluating a diversity of operational species criteria, including divergence in mtDNA (98 specimens; 2,781 bp) and nuclear loci (RAG؊1, 1,054 bp; BDNF 529 bp), ecological niches (11 bioclimatic variables; 285 unique localities), and cranial horn shapes (493 specimens; 16 landmarks). A phylogenetic analysis of mtDNA recovers 5 phylogeographic groups arranged latitudinally along the Baja California Peninsula and in California. The 2 southern phylogeographic groups exhibit concordance between genetic, morphological, and ecological divergence; however, differentiation is weak or absent at more recent levels defined by phylogeographic breaks in California. Interpreting these operational species criteria together suggests that there are 3 ecologically divergent and morphologically diagnosable species within the P. coronatum complex. Our 3-species taxonomic hypothesis invokes a deep coalescence event when fitting the mtDNA genealogy into the species tree, which is not unexpected for populations that have diverged recently. Although the hypothesis that the 3 phylogeographic groups distributed across California each represent distinctive species is not supported by all of the operational species criteria evaluated in this study, the conservation status of the imperiled populations represented by these genealogical units remains critical.evolution ͉ geometric morphometrics ͉ niche modeling ͉ phylogeography ͉ speciation

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“…Morphological variation in the molars was quantitatively analyzed using a geometric morphometric 338 model where shape was defined by placing a series of homologous landmarks at discrete anatomical 339 loci on the individual teeth (Zelditch et al 2004). The resulting Cartesian coordinate data were, after 340 the appropriate transformations, compared with PAST 2.17b.…”

Section: Geometric Morphometrics 311mentioning

confidence: 99%

Exploration of the taxonomy of some Pleistocene Cervini (Mammalia, Artiodactyla, Cervidae) from Java and Sumatra (Indonesia): a geometric- and linear morphometric approach

Gruwier

Vos

Kovarovic

2015

Quaternary Science Reviews

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2015) 'Exploration of the taxonomy of some PleistoceneCervini (Mammalia, Artiodactyla, Cervidae) from Java and Sumatra (Indonesia) : a geometric-and linear morphometric approach.', Quaternary science reviews., 119 . pp. 35-53. Further information on publisher's website:http://dx.doi.org/10. 1016/j.quascirev.2015.04.012 Publisher's copyright statement: NOTICE: this is the author's version of a work that was accepted for publication in Quaternary Science Reviews. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be re ected in this document. Changes may have been made to this work since it was submitted for publication. A de nitive version was subsequently published in Quaternary Science Reviews, 119, 1 July 2015, 10.1016/j.quascirev.2015.04.012. Additional information:Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

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Morphometrics and systematics

Cited by 331 publications

References 10 publications

Graptoloid diversity and disparity became decoupled during the Ordovician mass extinction

Graptoloid diversity and disparity became decoupled during the Ordovician mass extinction

Quantifying ecological, morphological, and genetic variation to delimit species in the coast horned lizard species complex ( Phrynosoma )

Exploration of the taxonomy of some Pleistocene Cervini (Mammalia, Artiodactyla, Cervidae) from Java and Sumatra (Indonesia): a geometric- and linear morphometric approach

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