Phylogenetic patterns and ontogenetic origins of limb length variation in ecologically diverse lacertine lizards

2020 ◽  
Author(s):  
Gerardo A Cordero ◽  
Anastasiia Maliuk ◽  
Xenia Schlindwein ◽  
Ingmar Werneburg ◽  
Oleksandr Yaryhin
Keyword(s):  
Habitat Preference ◽  
Habitat Associations ◽  
Limb Length ◽  
Habitat Specialization ◽  
Length Variation ◽  
Heterogeneous Environments ◽  
Historical Contingency ◽  
Adaptive Diversification ◽  
Interspecific Differences ◽  
Extant Species

Abstract Limb length is intrinsically linked to function and, ultimately, fitness. Thus, it can co-evolve with habitat structure, as exemplified by tropical lizards in highly heterogeneous environments. But does lizard limb length respond in a similar manner during adaptive diversification in temperate zones? Here, we examine variation in habitat preference and limb length in lacertine lizards from the Palaearctic. We tested the following three hypotheses: (1) species of the Lacertini tribe descended from a generalist ancestor and subsequently underwent habitat specialization; (2) specialized ecological roles are associated with relative limb length in extant species; and (3) interspecific differences in limb length emerge in embryonic development. Our comparisons supported an ancestral ‘rocky’ or ‘generalist’ habitat preference, and phenotype–habitat associations were particularly supported when examining size-adjusted forelimb length in 69 species that represented all known Lacertini genera. Moreover, we revealed an elevated interlimb ratio in high-vegetation species, which might be linked to climbing performance in species with relatively longer forelimbs. Furthermore, embryonic limb variation was detected solely against an Eremiadini outgroup species. Instead, hind limb length differences within Lacertini originated in post-hatching ontogeny. The mechanisms that modulate limb growth are likely to be limited in Lacertini, because adaptive morphological change might mirror historical contingency and the ecological context wherein this clade diversified.

scholarly journals Repeated modification of early limb morphogenesis programmes underlies the convergence of relative limb length in Anolis lizards

2011 ◽  
Vol 279 (1729) ◽  
pp. 739-748 ◽  
Author(s):  
Thomas J. Sanger ◽  
Liam J. Revell ◽  
Jeremy J. Gibson-Brown ◽  
Jonathan B. Losos
Keyword(s):  
Natural Selection ◽  
Developmental Trajectories ◽  
Limb Length ◽  
Long Bone ◽  
Length Variation ◽  
Developmental Processes ◽  
Independent Evolution ◽  
Limb Morphogenesis ◽  
Habitat Specialists ◽  
Phenotypic Convergence

The independent evolution of similar morphologies has long been a subject of considerable interest to biologists. Does phenotypic convergence reflect the primacy of natural selection, or does development set the course of evolution by channelling variation in certain directions? Here, we examine the ontogenetic origins of relative limb length variation among Anolis lizard habitat specialists to address whether convergent phenotypes have arisen through convergent developmental trajectories. Despite the numerous developmental processes that could potentially contribute to variation in adult limb length, our analyses reveal that, in Anolis lizards, such variation is repeatedly the result of changes occurring very early in development, prior to formation of the cartilaginous long bone anlagen.

scholarly journals Forest-type specialization strongly predicts avian responses to tropical agriculture

2019 ◽  
Vol 286 (1913) ◽  
pp. 20191724
Author(s):  
Jacob B. Socolar ◽  
David S. Wilcove
Keyword(s):  
Forest Type ◽  
Soil Nutrient ◽  
Predictive Performance ◽  
Species Traits ◽  
Habitat Associations ◽  
Habitat Specialization ◽  
Habitat Features ◽  
Specialist Species ◽  
Habitat Specialist Species ◽  
Poor Soil

Species’ traits influence how populations respond to land-use change. However, even in well-characterized groups such as birds, widely studied traits explain only a modest proportion of the variance in response across species. Here, we show that associations with particular forest types strongly predict the sensitivity of forest-dwelling Amazonian birds to agriculture. Incorporating these fine-scale habitat associations into models of population response dramatically improves predictive performance and markedly outperforms the functional traits that commonly appear in similar analyses. Moreover, by identifying habitat features that support assemblages of unusually sensitive habitat-specialist species, our model furnishes straightforward conservation recommendations. In Amazonia, species that specialize on forests along a soil–nutrient gradient (i.e. both rich-soil specialists and poor-soil specialists) are exceptionally sensitive to agriculture, whereas species that specialize on floodplain forests are unusually insensitive. Thus, habitat specialization per se does not predict disturbance sensitivity, but particular habitat associations do. A focus on conserving specific habitats that harbour highly sensitive avifaunas (e.g. poor-soil forest) would protect a critically threatened component of regional biodiversity. We present a conceptual model to explain the divergent responses of habitat specialists in the different habitats, and we suggest that similar patterns and conservation opportunities probably exist for other taxa and regions.

Large-scale stable isotope characterization of a Late Cretaceous dinosaur-dominated ecosystem

Geology ◽  
2020 ◽  
Vol 48 (6) ◽  
pp. 546-551
Author(s):  
T.M. Cullen ◽  
F.J. Longstaffe ◽  
U.G. Wortmann ◽  
L. Huang ◽  
F. Fanti ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Large Scale ◽  
Niche Partitioning ◽  
Community Response ◽  
Habitat Specialization ◽  
Future Research ◽  
Similar Data ◽  
Paleoenvironmental Reconstruction ◽  
Extant Species ◽  
Modern Analogue

Abstract In the Cretaceous of North America, environmental sensitivity and habitat specialization have been hypothesized to explain the surprisingly restricted geographic ranges of many large-bodied dinosaurs. Understanding the drivers behind this are key to determining broader trends of dinosaur species and community response to climate change under greenhouse conditions. However, previous studies of this question have commonly examined only small components of the paleo-ecosystem or operated without comparison to similar modern systems from which to constrain interpretations. Here we perform a high-resolution multi-taxic δ13C and δ18O study of a Cretaceous coastal floodplain ecosystem, focusing on species interactions and paleotemperature estimation, and compare with similar data from extant systems. Bioapatite δ13C preserves predator-prey offsets between tyrannosaurs and ornithischians (large herbivorous dinosaurs), and between aquatic reptiles and fish. Large ornithischians had broadly overlapping stable isotope ranges, contrary to hypothesized niche partitioning driven by specialization on coastal or inland subhabitat use. Comparisons to a modern analogue coastal floodplain show similar patterns of ecological guild structure and aquatic-terrestrial resource interchange. Multi-taxic oxygen isotope temperature estimations yield results for the Campanian of Alberta (Canada) consistent with the few other paleotemperature proxies available, and are validated when applied for extant species from a modern coastal floodplain, suggesting that this approach is a simple and effective avenue for paleoenvironmental reconstruction. Together, these new data suggest that dinosaur niche partitioning was more complex than previously hypothesized, and provide a framework for future research on dinosaur-dominated Mesozoic floodplain communities.

scholarly journals Adaptive diversification in heterogeneous environments

2017 ◽  
Vol 114 ◽  
pp. 1-9 ◽  
Author(s):  
Olivier David ◽  
Christian Lannou ◽  
Hervé Monod ◽  
Julien Papaïx ◽  
Djidi Traore
Keyword(s):  
Heterogeneous Environments ◽  
Adaptive Diversification

scholarly journals Stable isotope series from elephant ivory reveal lifetime histories of a true dietary generalist

2012 ◽  
Vol 279 (1737) ◽  
pp. 2433-2441 ◽  
Author(s):  
Jacqueline Codron ◽  
Daryl Codron ◽  
Matt Sponheimer ◽  
Kevin Kirkman ◽  
Kevin J. Duffy ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Resource Use ◽  
Isotope Analysis ◽  
Heterogeneous Environments ◽  
Diet Specialization ◽  
Annual Variations ◽  
Niche Specialization ◽  
Diet Variability ◽  
Extant Species ◽  
Elephant Ivory

Longitudinal studies have revealed how variation in resource use within consumer populations can impact their dynamics and functional significance in communities. Here, we investigate multi-decadal diet variations within individuals of a keystone megaherbivore species, the African elephant ( Loxodonta africana ), using serial stable isotope analysis of tusks from the Kruger National Park, South Africa. These records, representing the longest continuous diet histories documented for any extant species, reveal extensive seasonal and annual variations in isotopic—and hence dietary—niches of individuals, but little variation between them. Lack of niche distinction across individuals contrasts several recent studies, which found relatively high levels of individual niche specialization in various taxa. Our result is consistent with theory that individual mammal herbivores are nutritionally constrained to maintain broad diet niches. Individual diet specialization would also be a costly strategy for large-bodied taxa foraging over wide areas in spatio-temporally heterogeneous environments. High levels of within-individual diet variability occurred within and across seasons, and persisted despite an overall increase in inferred C 4 grass consumption through the twentieth century. We suggest that switching between C 3 browsing and C 4 grazing over extended time scales facilitates elephant survival through environmental change, and could even allow recovery of overused resources.

scholarly journals Convergence across a continent: adaptive diversification in a recent radiation of Australian lizards

2016 ◽  
Vol 283 (1832) ◽  
pp. 20160181 ◽  
Author(s):  
Mozes P. K. Blom ◽  
Paul Horner ◽  
Craig Moritz
Keyword(s):  
Adaptive Radiation ◽  
Ecological Speciation ◽  
Habitat Specialization ◽  
Ecological Framework ◽  
Diverse Group ◽  
Adaptive Diversification ◽  
Continental Scale ◽  
Exon Capture ◽  
Branch Lengths

Recent radiations are important to evolutionary biologists, because they provide an opportunity to study the mechanisms that link micro- and macroevolution. The role of ecological speciation during adaptive radiation has been intensively studied, but radiations can arise from a diversity of evolutionary processes; in particular, on large continental landmasses where allopatric speciation might frequently precede ecological differentiation. It is therefore important to establish a phylogenetic and ecological framework for recent continental-scale radiations that are species-rich and ecologically diverse. Here, we use a genomic (approx. 1 200 loci, exon capture) approach to fit branch lengths on a summary-coalescent species tree and generate a time-calibrated phylogeny for a recent and ecologically diverse radiation of Australian scincid lizards; the genus Cryptoblepharus . We then combine the phylogeny with a comprehensive phenotypic dataset for over 800 individuals across the 26 species, and use comparative methods to test whether habitat specialization can explain current patterns of phenotypic variation in ecologically relevant traits. We find significant differences in morphology between species that occur in distinct environments and convergence in ecomorphology with repeated habitat shifts across the continent. These results suggest that isolated analogous habitats have provided parallel ecological opportunity and have repeatedly promoted adaptive diversification. By contrast, speciation processes within the same habitat have resulted in distinct lineages with relatively limited morphological variation. Overall, our study illustrates how alternative diversification processes might have jointly stimulated species proliferation across the continent and generated a remarkably diverse group of Australian lizards.

Locomotor correlates of ecomorph designation in Anolis: an examination of three sympatric species from Jamaica

1992 ◽  
Vol 70 (4) ◽  
pp. 725-739 ◽  
Author(s):  
G. Lawrence Powell ◽  
Anthony P. Russell
Keyword(s):  
Body Size ◽  
Niche Partitioning ◽  
Sympatric Species ◽  
Limb Length ◽  
Greater Antilles ◽  
Adult Size ◽  
Allometric Models ◽  
Use Patterns ◽  
Interspecific Differences

Scaling of locomotor structures (limb length, scansor area, and intergirdle distance) in three Jamaican Anolis species (A. garmani, A. grahami, and A. opalinus) is examined. Reference to structural-niche use patterns and partitionings typical of these three species is made. Each species represents a separate Anolis ecomorph, differing from the others in adult size, shape, and structural niche. All are part of a single intra-island phyletic radiation. Allometric models indicate that intra- and inter-specific differences in proportion of locomotor structures are not necessarily ontogenetically invariant, but that all three species ontogenetically arrive at, or have attained, the differences in proportion typical of their adult sizes. Differences in adult proportion between two species are not functions of body size alone but are the products of different scaling trajectories. No intraspecific differences in structural-niche use are documented, but interspecific differences are well defined: the greater the number of differences in locomotor scaling between two species, the greater the structural-niche partitioning. We suggest that the locomotor structure scaling patterns observed in these three species are typical of the ecomorphs that they represent. Analogous ontogenetic patterns of development should be displayed by independently derived representatives of these ecomorphs from other Greater Antilles islands.

Habitat associations of woodcreeper (Aves: Dendrocolaptidae) assemblage in selectively logged areas of Southern Amazonia

2015 ◽  
Vol 32 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Domingos J. Rodrigues ◽  
Fernando P. Florêncio ◽  
Jocieli Oliveira ◽  
Dalci M. M. Oliveira ◽  
Gregory W. Lollback ◽  
...  
Keyword(s):  
Forest Structure ◽  
Negative Relationship ◽  
Bird Species ◽  
Forest Degradation ◽  
Habitat Associations ◽  
Selective Logging ◽  
Habitat Specialization ◽  
Canopy Openness ◽  
Southern Amazonia

Abstract:The Brazilian Amazon rain forest has lost c. 17% of its originally forested portion, due to deforestation and selective logging. Forest degradation caused by logging contributes to loss of animal species that require specialized habitats to survive, such as woodcreepers that inhabit understorey areas. Habitat associations of woodcreeper species can be important for identifying species that have restricted distribution and/or habitat specialization. Our study investigates the effects of spatial variation in forest structure and some landscape features (canopy openness, altitude, distance to stream and exploited basal area) on the abundance and composition of woodcreeper assemblage in selectively logged tropical forests in Southern Amazonia. We used mist-nets and points count to quantify the composition and abundance of woodcreepers in 32 plots in three sites. Plots were spatially arranged in PPBio LTER sites (long-term ecological research plots, systematically spaced at 1-km intervals) in Southern Amazonia. A total of 240 individuals (captured, observed and/or heard) belonging to 11 woodcreeper species were detected. Mantel tests showed that there is no spatial autocorrelation among woodcreeper assemblage and distance between plots. Altitude and canopy openness were significantly associated with the composition of the woodcreeper assemblage. Altitude was negatively associated with species richness, and the abundance of the two dominant species (Glyphorynchus spirurus and Xiphorhynchus elegans). The negative relationship with canopy openness suggests that woodcreeper assemblages that inhabit understorey are likely to be indirectly affected by selective logging which reduces canopy cover. The selective logging indirectly changes bird species assemblages, and depending on the intensity, may result in the local extinction of some insectivorous species. Short- and long-term studies addressing different intensities of selective logging are needed to determine the impacts on the bird species and forest structure.

scholarly journals Musculoskeletal modelling of sprawling and parasagittal forelimbs provides insight into synapsid postural transition

2021 ◽  
Author(s):  
Robert J Brocklehurst ◽  
Philip Fahn-Lai ◽  
Sophie Regnault ◽  
Stephanie E Pierce
Keyword(s):  
Shoulder Joint ◽  
Distinct Region ◽  
Functional Variation ◽  
Moment Arms ◽  
Interspecific Differences ◽  
Joint Range Of Motion ◽  
Musculoskeletal Models ◽  
Extant Species ◽  
Major Transition ◽  
Joint Range

The sprawling-parasagittal postural shift was a major transition during synapsid evolution and is considered key to mammalian ecological diversity. Despite a good fossil record, debate remains over when the shift to parasagittal posture occurred, primarily due to limited comparative biomechanical data on extant species. Here, we built forelimb musculoskeletal models of three extant taxa that bracket the sprawling-parasagittal transition: a tegu lizard, an echidna, and an opossum. We measured shoulder joint range of motion (ROM) about all three degrees of rotational freedom and characterized shoulder muscle moment arms (MMAs) across the entire pose space. Our results show that both the opossum and the tegu had high shoulder joint ROM, and both were substantially higher than the echidna. However, the opossum occupied a distinct region of pose space characterized by high humeral retraction angles. There are clear interspecific differences in MMAs related to posture, with the sprawling tegu and echidna emphasizing humeral depression, and the parasagittal opossum emphasizing humeral elevation. There are also notable differences between our sprawling taxa, with the echidna possessing much greater moment arms for humeral pronation than the tegu. We demonstrate clear functional variation between locomotor grades and use these data to hypothesize major shifts in forelimb function and posture along the mammalian stem.

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