scholarly journals Morphology, Ecology, and Biogeography of Independent Origins of Cleaning Behavior Around the World

2019 ◽  
Vol 59 (3) ◽  
pp. 625-637 ◽  
Author(s):  
Vikram B Baliga ◽  
Rita S Mehta
Keyword(s):  
Body Shape ◽  
Morphological Evolution ◽  
Small Body ◽  
Character Displacement ◽  
Phenotypic Evolution ◽  
Ecological Specialization ◽  
Selective Pressures ◽  
Cleaning Behavior ◽  
Marine Habitats ◽  
The Caribbean

Abstract Members of an ecological guild may be anticipated to show morphological convergence, as similar functional demands exert similar selective pressures on phenotypes. Nature is rife with examples, however, where such taxa instead exhibit ‘incomplete’ convergence or even divergence. Incorporating factors such as character displacement by other guild members or variation in ecological specialization itself may therefore be necessary to gain a more complete understanding of what constrains or promotes diversity. Cleaning, a behavior in which species remove and consume ectoparasites from “clientele,” has been shown to exhibit variation in specialization and has evolved in a variety of marine habitats around the globe. To determine the extent to which specialization in this tropic strategy has affected phenotypic evolution, we examined the evolution of cleaning behavior in five marine fish families: Labridae, Gobiidae, Pomacanthidae, Pomacentridae, and Embiotocidae. We used a comparative framework to determine patterns of convergence and divergence in body shape and size across non-cleaning and cleaning members within these five clades. Highly specialized obligate cleaning, found in the Indo-Pacific and the Caribbean, evolved in the Labridae and Gobiidae at strikingly similar times. In these two regions, obligate cleaning evolves early, shows convergence on an elongate body shape, and is restricted to species of small body size. Facultative cleaning, shown either throughout ontogeny or predominately in the juvenile phase, exhibits a much more varied phenotype, especially in geographic regions where obligate cleaning occurs. Collectively, our results are consistent with varying extents of an ecological specialization constraining or spurring morphological evolution in recurrent ways across regions.

scholarly journals Ectodysplasin signalling genes and phenotypic evolution in sculpins ( Cottus )

2015 ◽  
Vol 282 (1815) ◽  
pp. 20150746 ◽  
Author(s):  
Jie Cheng ◽  
Fritz Sedlazek ◽  
Janine Altmüller ◽  
Arne W. Nolte
Keyword(s):  
Body Shape ◽  
Morphological Evolution ◽  
Genomic Region ◽  
Phenotypic Evolution ◽  
Natural Hybrid ◽  
Microevolutionary Change ◽  
Trait Locus ◽  
Locus Mapping ◽  
Edar Gene

Despite their deeply conserved function among vertebrates, ectodysplasin (Eda) signalling genes are involved in microevolutionary change in humans and sticklebacks. If such a dual role is common, Eda signalling genes constitute hotspots for morphological evolution. Variation in sculpin ( Cottus ) skin prickling and body shape resembles patterns caused by variation in Eda signalling in sticklebacks. We mapped Eda signalling genes and performed quantitative trait locus mapping in crosses between Cottus rhenanus and Cottus perifretum . A genomic region containing the Eda receptor (Edar) was strongly associated with prickling and contributed to shape. The expression of Edar in developing prickles and skeletal elements in Cottus was confirmed by in situ hybridization. Coding sequence changes between Edar alleles in C. rhenanus and C. perifretum exceeded sequence differentiation in other vertebrates. However, it is likely that additional genetic elements besides coding changes affect the phenotypic variation. Although the phenotype in a natural hybrid lineage between C. rhenanus and C. perifretum resembles C. perifretum , the respective coding Edar alleles are not fully fixed (88.6%). Hence, our results support an involvement of Eda signalling in microevolutionary changes, but imply that the Edar gene is affected by multiple evolutionary processes that vary among freshwater sculpins.

A Cuticle Collagen Encoded by the lon-3 Gene May Be a Target of TGF-β Signaling in Determining Caenorhabditis elegans Body Shape

Genetics ◽  
2002 ◽  
Vol 162 (4) ◽  
pp. 1631-1639
Author(s):  
Yo Suzuki ◽  
Gail A Morris ◽  
Min Han ◽  
William B Wood
Keyword(s):  
Caenorhabditis Elegans ◽  
Body Shape ◽  
Small Body ◽  
Dependent Manner ◽  
Loss Of Function ◽  
Cellular Mechanisms ◽  
C Elegans ◽  
Gene Expression Analyses ◽  
Dose Dependent

Abstract The signaling pathway initiated by the TGF-β family member DBL-1 in Caenorhabditis elegans controls body shape in a dose-dependent manner. Loss-of-function (lf) mutations in the dbl-1 gene cause a short, small body (Sma phenotype), whereas overexpression of dbl-1 causes a long body (Lon phenotype). To understand the cellular mechanisms underlying these phenotypes, we have isolated suppressors of the Sma phenotype resulting from a dbl-1(lf) mutation. Two of these suppressors are mutations in the lon-3 gene, of which four additional alleles are known. We show that lon-3 encodes a collagen that is a component of the C. elegans cuticle. Genetic and reporter-gene expression analyses suggest that lon-3 is involved in determination of body shape and is post-transcriptionally regulated by the dbl-1 pathway. These results support the possibility that TGF-β signaling controls C. elegans body shape by regulating cuticle composition.

scholarly journals Biomechanical trade-offs bias rates of evolution in the feeding apparatus of fishes

2011 ◽  
Vol 279 (1732) ◽  
pp. 1287-1292 ◽  
Author(s):  
Roi Holzman ◽  
David C. Collar ◽  
Samantha A. Price ◽  
C. Darrin Hulsey ◽  
Robert C. Thomson ◽  
...  
Keyword(s):  
Genetic Factors ◽  
Morphological Evolution ◽  
The Body ◽  
Body Parts ◽  
Phenotypic Evolution ◽  
Genetic Constraints ◽  
Functional Systems ◽  
Rates Of Evolution ◽  
Trade Offs

Morphological diversification does not proceed evenly across the organism. Some body parts tend to evolve at higher rates than others, and these rate biases are often attributed to sexual and natural selection or to genetic constraints. We hypothesized that variation in the rates of morphological evolution among body parts could also be related to the performance consequences of the functional systems that make up the body. Specifically, we tested the widely held expectation that the rate of evolution for a trait is negatively correlated with the strength of biomechanical trade-offs to which it is exposed. We quantified the magnitude of trade-offs acting on the morphological components of three feeding-related functional systems in four radiations of teleost fishes. After accounting for differences in the rates of morphological evolution between radiations, we found that traits that contribute more to performance trade-offs tend to evolve more rapidly, contrary to the prediction. While ecological and genetic factors are known to have strong effects on rates of phenotypic evolution, this study highlights the role of the biomechanical architecture of functional systems in biasing the rates and direction of trait evolution.

The Intellectual Challenge of Morphological Evolution: A Case for Variational Structuralism

2014 ◽  
Author(s):  
Günter P. Wagner
Keyword(s):  
Developmental Biology ◽  
Evolutionary Biology ◽  
Morphological Evolution ◽  
Evolutionary Developmental Biology ◽  
Phenotypic Evolution ◽  
Developmental Variation ◽  
Core Idea ◽  
Intellectual Challenge

This chapter explores variational structuralism, whose core idea is that organisms and their parts play causal roles in shaping the patterns of phenotypic evolution. Drawing on the work of pioneers such as Ron Amundson, it discusses the conceptual incompatibilities between two styles of thinking in evolutionary biology: functionalism and structuralism. It proceeds by explaining the meaning of developmental types and structuralist concepts arising from macromolecular studies. It also examines facts and ideas about bodies, Rupert Riedl's theory of the “immitatory epigenotype,” and Neil Shubin and Pere Alberch's developmental interpretation of tetrapod limbs. Finally, it looks at the emergence of molecular structuralism and the enigma of developmental variation. The chapter argues that typology naturally emerged from the facts of evolutionary developmental biology and that it would be seriously problematic to try to avoid it.

scholarly journals Phylogenomics, Biogeography, and Morphometrics Reveal Rapid Phenotypic Evolution in Pythons After Crossing Wallace’s Line

2020 ◽  
Vol 69 (6) ◽  
pp. 1039-1051 ◽  
Author(s):  
Damien Esquerré ◽  
Stephen Donnellan ◽  
Ian G Brennan ◽  
Alan R Lemmon ◽  
Emily Moriarty Lemmon ◽  
...  
Keyword(s):  
Body Shape ◽  
Habitat Preferences ◽  
Ecological Niches ◽  
Mitochondrial Genomes ◽  
Phenotypic Evolution ◽  
Conservative Group ◽  
Anchored Hybrid Enrichment ◽  
Nuclear Loci ◽  
Wallace’S Line ◽  
Diverse Groups

Abstract Ecological opportunities can be provided to organisms that cross stringent biogeographic barriers towards environments with new ecological niches. Wallace’s and Lyddeker’s lines are arguably the most famous biogeographic barriers, separating the Asian and Australo-Papuan biotas. One of the most ecomorphologically diverse groups of reptiles, the pythons, is distributed across these lines, and are remarkably more diverse in phenotype and ecology east of Lydekker’s line in Australo-Papua. We used an anchored hybrid enrichment approach, with near complete taxon sampling, to extract mitochondrial genomes and 376 nuclear loci to resolve and date their phylogenetic history. Biogeographic reconstruction demonstrates that they originated in Asia around 38-45 Ma and then invaded Australo-Papua around 23 Ma. Australo-Papuan pythons display a sizeable expansion in morphological space, with shifts towards numerous new adaptive optima in head and body shape, coupled with the evolution of new micro-habitat preferences. We provide an updated taxonomy of pythons and our study also demonstrates how ecological opportunity following colonization of novel environments can promote morphological diversification in a formerly ecomorphologically conservative group. [Adaptive radiation; anchored hybrid enrichment; biogeography; morphometrics; snakes.]

scholarly journals Solitary ecology as a phenomenon extending beyond insular systems: exaptive evolution in Anolis lizards

2019 ◽  
Vol 15 (5) ◽  
pp. 20190056 ◽  
Author(s):  
Julián A. Velasco ◽  
Steven Poe ◽  
Constantino González-Salazar ◽  
Oscar Flores-Villela
Keyword(s):  
Body Size ◽  
Adaptive Evolution ◽  
Environmental Filtering ◽  
Phenotypic Evolution ◽  
Phenotypic Differentiation ◽  
Evolutionary Transitions ◽  
Ecological Release ◽  
Selective Pressures ◽  
Island Species

The mechanisms driving phenotypic evolution have been of interest to biologists since Darwin. Ecological release—wherein adaptive evolution occurs following relaxation of constraining selective pressures—and environmental filtering—wherein exaptive traits allow colonization of a new area—have been studied in several insular cases. Anolis lizards, which may exist in solitude or sympatry with multiple congeners, are an excellent system for evaluating whether ecological release and environmental filtering are associated with phenotypic shifts across phylogenetic and geographical scales. Insular solitary Anolis exhibit phenotypic differentiation in body size and sexual size dimorphism—SSD—through exaptive and adaptive evolution, respectively. But, the generality of these effects has not yet been addressed. Here, we analyse the evolution of body size and SSD relative to sympatry in mainland Anolis . We found that mainland species co-occurring with few congeners exhibit uniform body size and greater SSD relative to other random mainland assemblages, consistent with the insular solitary pattern. The locations of evolutionary shifts for both traits do not coincide with evolutionary transitions to decreased levels of sympatry. These results are consistent with exaptive environmental filtering but not adaptive ecological release. Future studies should be conducted at local scales to evaluate the role of these factors in the evolution of solitary existence in mainland and island species.

scholarly journals Do Coral Reefs Promote Morphological Diversification? Exploration of Habitat Effects on Labrid Pharyngeal Jaw Evolution in the Era of Big Data

2019 ◽  
Vol 59 (3) ◽  
pp. 696-704 ◽  
Author(s):  
Kory M Evans ◽  
Keiffer L Williams ◽  
Mark W Westneat
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Morphological Evolution ◽  
Morphological Data ◽  
Shape Evolution ◽  
Micro Computed Tomography ◽  
Functional Variation ◽  
Morphological Diversification ◽  
Marine Habitats ◽  
Pharyngeal Jaw

Abstract Coral reefs are complex marine habitats that have been hypothesized to facilitate functional specialization and increased rates of functional and morphological evolution. Wrasses (Labridae: Percomorpha) in particular, have diversified extensively in these coral reef environments and have evolved adaptations to further exploit reef-specific resources. Prior studies have found that reef-dwelling wrasses exhibit higher rates of functional evolution, leading to higher functional variation than in non-reef dwelling wrasses. Here, we examine this hypothesis in the lower pharyngeal tooth plate of 134 species of reef and non-reef-associated labrid fishes using high-resolution morphological data in the form of micro-computed tomography scans and employing three-dimensional geometric morphometrics to quantify shape differences. We find that reef-dwelling wrasses do not differ from non-reef-associated wrasses in morphological disparity or rates of shape evolution. However, we find that some reef-associated species (e.g., parrotfishes and tubelips) exhibit elevated rates of pharyngeal jaw shape evolution and have colonized unique regions of morphospace. These results suggest that while coral reef association may provide the opportunity for specialization and morphological diversification, species must still be able to capitalize on the ecological opportunities to invade novel niche space, and that these novel invasions may prompt rapid rates of morphological evolution in the associated traits that allow them to capitalize on new resources.

Potential invasion of the Gulf of Mexico by Protemblemaria punctata (Teleostei: Chaenopsidae), a cryptobenthic fish endemic to Venezuela

2020 ◽  
Author(s):  
Jimmy Argüelles-Jiménez ◽  
Merari Contreras-Juarez ◽  
Eduardo Palacio Pérez
Keyword(s):  
Invasive Species ◽  
Gulf Of Mexico ◽  
Small Body ◽  
The Past ◽  
Oil Platforms ◽  
Offshore Oil Platforms ◽  
Viable Population ◽  
Body Sizes ◽  
The Caribbean ◽  
Offshore Oil

The movement of species to areas outside their native ranges has greatly intensified over the past few decades. However, detecting invasive species often requires detailed and regular surveys, especially for animals with small body sizes. A cryptobenthic fish endemic to the Caribbean coast of Venezuela, Protemblemaria punctata (Cervigón, 1966), is reported here from the southwestern Gulf of Mexico, based on the collection of 8 specimens (5 males and 3 females) from Bajo Mersey, a coral reef in the Parque Nacional Sistema Arrecifal Veracruzano (PNSAV). The collected specimens were taken from sessile worm tubes that grew on PVC structures previously placed on the reef at a depth of 6 m. The number of P. punctata specimens we collected could indicate that the species has established a viable population on the reefs in the PNSAV. The colonization of P. punctata in the Gulf of Mexico waters may be due to the dispersal of individuals present on offshore oil platforms that are transported from Trinidad to Venezuela and the Gulf of Mexico.

scholarly journals Iterative adaptive radiations of fossil canids show no evidence for diversity-dependent trait evolution

2015 ◽  
Vol 112 (16) ◽  
pp. 4897-4902 ◽  
Author(s):  
Graham J. Slater
Keyword(s):  
Adaptive Radiation ◽  
Morphological Evolution ◽  
Empirical Support ◽  
Phenotypic Evolution ◽  
Ecological Opportunity ◽  
Radiation Theory ◽  
Molar Teeth ◽  
Adaptive Radiations ◽  
Adaptive Peak ◽  
Adaptive Zone

A long-standing hypothesis in adaptive radiation theory is that ecological opportunity constrains rates of phenotypic evolution, generating a burst of morphological disparity early in clade history. Empirical support for the early burst model is rare in comparative data, however. One possible reason for this lack of support is that most phylogenetic tests have focused on extant clades, neglecting information from fossil taxa. Here, I test for the expected signature of adaptive radiation using the outstanding 40-My fossil record of North American canids. Models implying time- and diversity-dependent rates of morphological evolution are strongly rejected for two ecologically important traits, body size and grinding area of the molar teeth. Instead, Ornstein–Uhlenbeck processes implying repeated, and sometimes rapid, attraction to distinct dietary adaptive peaks receive substantial support. Diversity-dependent rates of morphological evolution seem uncommon in clades, such as canids, that exhibit a pattern of replicated adaptive radiation. Instead, these clades might best be thought of as deterministic radiations in constrained Simpsonian subzones of a major adaptive zone. Support for adaptive peak models may be diagnostic of subzonal radiations. It remains to be seen whether early burst or ecological opportunity models can explain broader adaptive radiations, such as the evolution of higher taxa.

scholarly journals No latitudinal gradients in tempo or mode of morphological evolution in birds

2020 ◽  
Author(s):  
J. Drury ◽  
J. Clavel ◽  
J.A. Tobias ◽  
J. Rolland ◽  
C. Sheard ◽  
...  
Keyword(s):  
Species Interactions ◽  
Morphological Evolution ◽  
Latitudinal Gradients ◽  
Phenotypic Evolution ◽  
Trait Evolution ◽  
Trait Divergence ◽  
Diversity Gradient ◽  
The Tropics ◽  
The Impact ◽  
Phylogenetic Models

AbstractThe latitudinal diversity gradient is one of the most striking patterns in nature yet its implications for morphological evolution are poorly understood. In particular, it has been proposed that an increased intensity of species interactions in tropical biota may either promote or constrain trait evolution, but which of these outcomes predominates remains uncertain. Here, we develop tools for fitting phylogenetic models of phenotypic evolution in which the impact of species interactions can vary across lineages. Deploying these models on a global avian trait dataset to explore differences in trait divergence between tropical and temperate lineages, we find that the effect of latitude on the mode and tempo of morphological evolution is weak and clade- or trait-dependent. Our results indicate that species interactions do not disproportionately impact morphological evolution in tropical bird families and question the validity and universality of previously reported patterns of slower trait evolution in the tropics.

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