Continuous and Arrested Morphological Diversification in Sister Clades of Characiform Fishes: A Phylomorphospace Approach

Sidlauskas, Brian L.

doi:10.1111/j.1558-5646.2008.00519.x

Cited by 385 publications

(445 citation statements)

References 140 publications

(227 reference statements)

Supporting

Mentioning

428

Contrasting

Unclassified

Order By: Relevance

“…Conceptually, this is similar to making a distinction between magnitude of change along branches and direction of changes along branches (33). To explore this further, we calculated phylogenetic signal in the PCO1 and PCO2 scores shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…We estimated the total disparity within each echinoid group by summing the variance along each positive eigenvector; 95% confidence intervals are based on bootstrapping with replacement (1,000 times). We mapped the phylogenetic history onto the morphospace using the phytools package in R (46); in this implementation, the principal coordinate scores of the ancestral nodes are estimated using a maximum likelihood algorithm (33,47). However, we use this only to illustrate the phylogenetic structure between taxa, and do not attempt to draw conclusions about the morphology at those nodes.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Dynamic evolutionary change in post-Paleozoic echinoids and the importance of scale when interpreting changes in rates of evolution

Hopkins

Smith

2015

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

122

183

View full text Add to dashboard Cite

How ecological and morphological diversity accrues over geological time has been much debated by paleobiologists. Evidence from the fossil record suggests that many clades reach maximal diversity early in their evolutionary history, followed by a decline in evolutionary rates as ecological space fills or due to internal constraints. Here, we apply recently developed methods for estimating rates of morphological evolution during the post-Paleozoic history of a major invertebrate clade, the Echinoidea. Contrary to expectation, rates of evolution were lowest during the initial phase of diversification following the Permo-Triassic mass extinction and increased over time. Furthermore, although several subclades show high initial rates and net decreases in rates of evolution, consistent with "early bursts" of morphological diversification, at more inclusive taxonomic levels, these bursts appear as episodic peaks. Peak rates coincided with major shifts in ecological morphology, primarily associated with innovations in feeding strategies. Despite having similar numbers of species in today's oceans, regular echinoids have accrued far less morphological diversity than irregular echinoids due to lower intrinsic rates of morphological evolution and less morphological innovation, the latter indicative of constrained or bounded evolution. These results indicate that rates of evolution are extremely heterogenous through time and their interpretation depends on the temporal and taxonomic scale of analysis.fossil record | morphological diversification | early bursts | evolutionary innovation | mode of evolution A ssessing how rates of morphological evolution have changed over geological time has been a major research goal of evolutionary paleobiologists since Westoll's classic study of lungfish evolution (1). A common pattern to emerge from the fossil record is that many clades reach maximal morphological diversity early in their evolutionary history (2-4). This sort of pattern could be the result of an "early burst" of morphological diversification as taxa diverge followed by a slow-down in rates as ecological space becomes filled (5, 6). Internal constraint or long-term selective pressures could also limit overall disparity, leading to a slowdown in the rate of new trait acquisition over time (7,8). However, only a small proportion of fossil disparity studies have also assessed changes in rates of evolution within lineages (e.g., along phylogenetic branches) thereby providing a more nuanced understanding of how this disparity came about (e.g., refs. 9-13). Simultaneously, decreasing rates in trait evolution have been difficult to detect using phylogenetic comparative data of extant taxa, because of low statistical power (14, 15), loss of signal through extinction (16), and inaccuracies in reconstructing ancestral nodes (17). Here we take advantage of recently developed methods for directly estimating per-lineage-million-year rates of evolution from phylogenies with both fossil and living taxa to test whether declining rates ch...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Dynamic evolutionary change in post-Paleozoic echinoids and the importance of scale when interpreting changes in rates of evolution

Hopkins

Smith

2015

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

122

183

View full text Add to dashboard Cite

show abstract

“…This result undoubtedly reflects the strong integration observed between the beak and braincase. The considerable crossing of clades over morphospace indicates low disparity of forms relative to the number of species (45), indicating that raptors are thoroughly exploring a tightly constrained morphological space, through either extensive convergence or, alternatively, limited shape change from a basal morphological state.…”

Section: Discussionmentioning

confidence: 99%

The shapes of bird beaks are highly controlled by nondietary factors

Bright

Marugán‐Lobón

Cobb

et al. 2016

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

215

274

View full text Add to dashboard Cite

Bird beaks are textbook examples of ecological adaptation to diet, but their shapes are also controlled by genetic and developmental histories. To test the effects of these factors on the avian craniofacial skeleton, we conducted morphometric analyses on raptors, a polyphyletic group at the base of the landbird radiation. Despite common perception, we find that the beak is not an independently targeted module for selection. Instead, the beak and skull are highly integrated structures strongly regulated by size, with axes of shape change linked to the actions of recently identified regulatory genes. Together, size and integration account for almost 80% of the shape variation seen between different species to the exclusion of morphological dietary adaptation. Instead, birds of prey use size as a mechanism to modify their feeding ecology. The extent to which shape variation is confined to a few major axes may provide an advantage in that it facilitates rapid morphological evolution via changes in body size, but may also make raptors especially vulnerable when selection pressures act against these axes. The phylogenetic position of raptors suggests that this constraint is prevalent in all landbirds and that breaking the developmental correspondence between beak and braincase may be the key novelty in classic passerine adaptive radiations.geometric morphometrics | integration | allometry | birds | modularity T he avian beak offers a classic example of adaptation to feeding ecology, with beak morphology frequently considered to represent evolutionary adaptation to specialized trophic niches [e.g., Galápagos finches (1), Hawaiian honeycreepers (2), and Madagascan vangas (3)]. Despite this axiom, we lack quantitative data on the degree to which skull and beak morphology is influenced not only by feeding ecology, but also by other sources of variation or constraint (4). Although the beak is often seen as the target of selection mechanisms closely allied to feeding ecology, such as prey type, feeding style, or beak use, evidence also suggests that beak morphology and variation may be constrained by a number of other factors, including evolutionary history (phylogeny) and development on the component parts of the entire skull. Breakthrough experiments in molecular genetics have shown that the mechanisms driving beak shape variation encompass modifications to the timing of expression of conserved developmental pathways (5-9), resulting in beak diversity described by a few relatively simple geometric transformations (10). However, pleiotropic associations between different skull structures can also contribute to the shape of the avian beak (11), and Sonic hedgehog signaling from the forebrain also relates to the spatial organization of, and changes to, face and beak shape (12)(13)(14). Furthermore, assessments of bird skull phenotypic variation suggest that beak morphology may evolve cohesively with cranial morphology (15,16). Size is also an important consideration when assessing morphological variation. Larger animals gene...

show abstract

“…A phylomorphospace diagram depicts the magnitude and direction of shape changes among branches of a clade in a multivariate shape space. This is performed by combining a previously proposed phylogeny with the scatter plots of principal components (PC) scores computed from a PCA and projecting this phylogeny onto a two‐dimensional plane where branch lengths and distances are inferred by the differences in shape between groups using squared‐changed parsimony (Sidlauskas, 2008). Treefiles were built based of the Tagliacollo, Bernt, Craig, Oliveira, & Albert (2015) phylogeny using the software Mesquite v. 2.75 (Maddison & Maddison, 2001) and imported to MorphoJ (Klingenberg, 2011) as a Nexus file using the option “map onto phylogeny.”…”

Section: Methodsmentioning

confidence: 99%

Why the short face? Developmental disintegration of the neurocranium drives convergent evolution in neotropical electric fishes

Evans

Waltz

Tagliacollo

et al. 2017

Ecology and Evolution

View full text Add to dashboard Cite

Convergent evolution is widely viewed as strong evidence for the influence of natural selection on the origin of phenotypic design. However, the emerging evo‐devo synthesis has highlighted other processes that may bias and direct phenotypic evolution in the presence of environmental and genetic variation. Developmental biases on the production of phenotypic variation may channel the evolution of convergent forms by limiting the range of phenotypes produced during ontogeny. Here, we study the evolution and convergence of brachycephalic and dolichocephalic skull shapes among 133 species of Neotropical electric fishes (Gymnotiformes: Teleostei) and identify potential developmental biases on phenotypic evolution. We plot the ontogenetic trajectories of neurocranial phenotypes in 17 species and document developmental modularity between the face and braincase regions of the skull. We recover a significant relationship between developmental covariation and relative skull length and a significant relationship between developmental covariation and ontogenetic disparity. We demonstrate that modularity and integration bias the production of phenotypes along the brachycephalic and dolichocephalic skull axis and contribute to multiple, independent evolutionary transformations to highly brachycephalic and dolichocephalic skull morphologies.

show abstract

Continuous and Arrested Morphological Diversification in Sister Clades of Characiform Fishes: A Phylomorphospace Approach

Abstract: Understanding how and why certain clades diversify greatly in morphology whereas

Cited by 385 publications

References 140 publications

Dynamic evolutionary change in post-Paleozoic echinoids and the importance of scale when interpreting changes in rates of evolution

Dynamic evolutionary change in post-Paleozoic echinoids and the importance of scale when interpreting changes in rates of evolution

The shapes of bird beaks are highly controlled by nondietary factors

Why the short face? Developmental disintegration of the neurocranium drives convergent evolution in neotropical electric fishes

Contact Info

Product

Resources

About