scholarly journals Influence of phylogenetic structure and climate gradients on geographical variation in the morphology of Mexican flycatcher forests assemblages (Aves: Tyrannidae)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6754 ◽  
Author(s):  
Gala Cortés-Ramírez ◽  
César A. Ríos-Muñoz ◽  
Adolfo G. Navarro-Sigüenza

Morphological variation is strongly related to variation in the ecological characteristics and evolutionary history of each taxon. To explore how geographical variation in morphology is related to different climatic gradients and phylogenetic structure, we analyzed the variation of morphological traits (body size, bill, and wing) of 64 species of tyrant flycatchers (Tyrannidae) distributed in Mexico. We measured these morphological traits in specimens from biological collections and related them to the climatic and topographic data of each collection locality. We performed the analyses separately at two levels: (1) the regional level and (2) the assemblage level, which was split into (assemblage I) lowland forests and (assemblage II) highland forests and other vegetation types. We also calculated the phylogenetic structure of flycatchers of each locality in order to explore the influence of climatic variables and the phylogenetic structure on the morphological variation of tyrant flycatchers, by means of linear mixed-effects models. We mapped the spatial variation of the relationship between morphological traits and environmental gradients, taking into account the phylogenetic structure. Important climatic variables explaining the morphological variation were those of temperature ranges (seasonality) and the results suggest that the phylogenetic clustering increases towards the highlands of Sierra Madre Oriental and Sierra Madre del Sur, and the lowlands of Balsas Depression. For the regional level, the spatial distribution of body size showed a pattern coincident with Bergmann’s rule, with increasing in size from south to north. In the tropical lowland forests assemblage, body size tend to increase in seasonally dry forests (western Mexico) and decrease in the humid ones (eastern Mexico). In the assemblage of highland forests and other types of vegetation, morphological trait values increased northeast to southwest. Phylogenetic structure helped to explain the variation of morphology at the assemblage level but not at the regional level. The patterns of trait variation in the lowland and highland assemblages suggest that parts of morphological variation are explained both by the climatic gradients and by the lineage relatedness of communities. Overall, our results suggest that morphological variation is best explained by a varied set of variables, and that regression models representing this variation, as well as integrating phylogenetic patterns at different community levels, provide a new understanding of the mechanisms underlying the links among biodiversity, its geographical setting, and environmental change.

Primates ◽  
2021 ◽  
Author(s):  
Madeleine Geiger

AbstractHuman impact influences morphological variation in animals, as documented in many captive and domestic animal populations. However, there are different levels of human impact, and their influence on the pattern and rate of morphological variation remains unclear. This study contributes to the ongoing debate via the examination of cranial and mandibular shape and size variation and pace of change in Japanese macaques (Macaca fuscata). This species is ideal for tackling such questions because different wild, wild-provisioned, and captive populations have been monitored and collected over seven decades. Linear measurements were taken on 70 skulls from five populations, grouped into three ‘human impact groups’ (wild, wild-provisioned, and captive). This made it possible to investigate the pattern and pace of skull form changes among the human impact groups as well as over time within the populations. It was found that the overall skull shape tends to differ among the human impact groups, with captive macaques having relatively longer rostra than wild ones. Whether these differences are a result of geographic variation or variable human impact, related to nutritional supply and mechanical properties of the diet, is unclear. However, this pattern of directed changes did not seem to hold when the single captive populations were examined in detail. Although environmental conditions have probably been similar for the two examined captive populations (same captive locality), skull shape changes over the first generations in captivity were mostly different. This varying pattern, together with a consistent decrease in body size in the captive populations over generations, points to genetic drift playing a role in shaping skull shape and body size in captivity. In the captive groups investigated here, the rates of change were found to be high compared to literature records from settings featuring different degrees of human impact in different species, although they still lie in the range of field studies in a natural context. This adds to the view that human impact might not necessarily lead to particularly fast rates of change.


2007 ◽  
Vol 85 (12) ◽  
pp. 1275-1285 ◽  
Author(s):  
Sebastián P. Luque ◽  
Edward H. Miller ◽  
John P.Y. Arnould ◽  
Magaly Chambellant ◽  
Christophe Guinet

Pre- and post-weaning functional demands on body size and shape of mammals are often in conflict, especially in species where weaning involves a change of habitat. Compared with long lactations, brief lactations are expected to be associated with fast rates of development and attainment of adult traits. We describe allometry and growth for several morphological traits in two closely related fur seal species with large differences in lactation duration at a sympatric site. Longitudinal data were collected from Antarctic ( Arctocephalus gazella (Peters, 1875); 120 d lactation) and subantarctic ( Arctocephalus tropicalis (Gray, 1872); 300 d lactation) fur seals. Body mass was similar in neonates of both species, but A. gazella neonates were longer, less voluminous, and had larger foreflippers. The species were similar in rate of preweaning growth in body mass, but growth rates of linear variables were faster for A. gazella pups. Consequently, neonatal differences in body shape increased over lactation, and A. gazella pups approached adult body shape faster than did A. tropicalis pups. Our results indicate that preweaning growth is associated with significant changes in body shape, involving the acquisition of a longer, more slender body with larger foreflippers in A. gazella. These differences suggest that A. gazella pups are physically more mature at approximately 100 d of age (close to weaning age) than A. tropicalis pups of the same age.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5370 ◽  
Author(s):  
Caterina Penone ◽  
Christian Kerbiriou ◽  
Jean-François Julien ◽  
Julie Marmet ◽  
Isabelle Le Viol

Background Citizen monitoring programs using acoustic data have been useful for detecting population and community patterns. However, they have rarely been used to study broad scale patterns of species traits. We assessed the potential of acoustic data to detect broad scale patterns in body size. We compared geographical patterns in body size with acoustic signals in the bat species Pipistrellus pipistrellus. Given the correlation between body size and acoustic characteristics, we expected to see similar results when analyzing the relationships of body size and acoustic signals with climatic variables. Methods We assessed body size using forearm length measurements of 1,359 bats, captured by mist nets in France. For acoustic analyses, we used an extensive dataset collected through the French citizen bat survey. We isolated each bat echolocation call (n = 4,783) and performed automatic measures of signals, including the frequency of the flattest part of the calls (characteristic frequency). We then examined the relationship between forearm length, characteristic frequencies, and two components resulting from principal component analysis for geographic (latitude, longitude) and climatic variables. Results Forearm length was positively correlated with higher precipitation, lower seasonality, and lower temperatures. Lower characteristic frequencies (i.e., larger body size) were mostly related to lower temperatures and northern latitudes. While conducted on different datasets, the two analyses provided congruent results. Discussion Acoustic data from citizen science programs can thus be useful for the detection of large-scale patterns in body size. This first analysis offers a new perspective for the use of large acoustic databases to explore biological patterns and to address both theoretical and applied questions.


2019 ◽  
Vol 18 (2) ◽  
pp. 195-207
Author(s):  
Carolina Nisa Ramiro ◽  
Renato Sousa Recoder ◽  
Miguel Trefaut Rodrigues

Geographic variation in the morphology of the sand-dwelling lizard Nothobachia ablephara (Squamata: Gymnophthalmidae). Nothobachia ablephara is a small microteiid lizard with an elongated body and reduced limbs; it occurs in isolated dune felds in the state of Bahia (Xique-Xique and Alagoado) and small sandy patches in northeastern Brazil. A previous molecular study found a marked mtDNA divergence between populations of N. ablephara from Alagoado and Xique-Xique dunes, suggesting that the two populations diverged from one another between 3 and 4 million years ago. Given this isolation, it is interesting to explore whether morphological traits of the lizards refect the reported genetic divergence of the populations. Scale counts of the sexes and the populations differ signifcantly, but there is considerable overlap of values. Univariate and multivariate analyses revealed signifcant morphometric variation between sexes and populations; however, this is mostly explained by size differences. Females are larger than males in all characters that are sexually dimorphic, and individuals from Xique-Xique are larger than those from Alagoado in all characters that vary geographically. The sample from Alagoado has more sexually dimorphic characters than the one from Xique-Xique. Although N. ablephara displays some geographical variation, the two populations could not be unequivocally distinguished by scale counts and morphometric data.


2014 ◽  
Vol 6 (2) ◽  
pp. 178-184 ◽  
Author(s):  
KiByung LIM ◽  
Adnan YOUNIS ◽  
Jong TAEK PARK ◽  
Yoon JUNG HWANG

In this study naturally growing morphological variation of Lilium tsingtauense (Korean wheel lily), from southern Chung San Island to northern Mount Seorak, was investigated in 16 habitats around the country. Morphological analysis revealed that this species had its own unique characteristics in different habitats. Flowers with luster are in actinomorphic form, with shades of orange, each plant having an average of 2.4 flowers that blossom upward. The shape of flower petals was from oval to oblong. The width of the petals, which determines the shape of the flower, significantly varied among regions. Flower petals showed purple spots and its occurrence greatly varied among plants from almost none to 300 spots per flower. In addition, when the number of spots increased, the flower color was more vivid. Leaves were typically one-tiered verticillate and most of the leaves were long, oval and some were lanceolate. Young leaves showed definitive patterns that faded during growth. Starting from the verticillate leaves, stems below the leaves were smooth, although 81% of all stems, above the verticillate leaves, showed rough micro-protrusions. Bulb shapes were long and vertically elliptical. The ramentum was light yellow in color and the base was darker, with the color fading toward the upper region of the plant. The shape of the ramentum was long, with a pointy end, and its adhesiveness was weak. This study offers basic fundamental information for the effective exploitation and recognition of L. tsingtauense resources as a potential cut flower and potting plant in floral trade worldwide.


2010 ◽  
Vol 41 ◽  
pp. 159-165 ◽  
Author(s):  
S. A. Brooks ◽  
S. Makvandi-Nejad ◽  
E. Chu ◽  
J. J. Allen ◽  
C. Streeter ◽  
...  

Author(s):  
P. Vermeiren ◽  
C. Lennard ◽  
C. Trave

Abstract Intertidal crabs display distinct morphological traits that allow differential interactions with biotic and abiotic features of the intertidal landscape, but are also influenced by allometry and sexual selection. This study aimed to explore the influence of sexual, allometric and habitat factors on morphological variation in the intertidal mangrove crab assemblage. A standardized photographic protocol was developed using readily available, low-cost technology to capture the morphology of carapaces and claws as sets of Cartesian landmarks. Digitization errors were 1 to 2 orders of magnitude smaller than the variation among individuals. In Tubuca seismella and Tubuca signata (superfamily Ocypodoidea), species that have traditionally been studied for sexual dimorphism, standardized major claw sizes were 2.8 and 3.7, respectively, times larger for males than females. Sexual dimorphism in claw size was also observed for Metopograpsus frontalis and Parasesarma longicristatum (superfamily Grapsoidea), with the largest claw in males being 15% and 33%, respectively, larger than in females. In contrast to size, claw shape did not relate to sex, except for T. seismella. Carapace shape, although variable among individuals and displaying asymmetry, was unrelated to sex. Claw and carapace shapes displayed high correlations, with values around 0.78. Carapace shapes grouped into taxonomic families and linked to habitat preferences, while claw shapes varied along a taxonomic gradient. These results complement studies on crab morphology that focus on specific factors or species, and stress the importance of multiple, interacting factors including sexual, allometric and habitat influences as drivers of morphological trait variability.


Zootaxa ◽  
2020 ◽  
Vol 4860 (3) ◽  
pp. 352-374
Author(s):  
SERGEY G. ERMILOV ◽  
NIKOLAY A. RYABININ

The genus Parabelbella (Oribatida, Damaeidae), with nine known species, is distributed in the Holarctic and Neotropical regions; of these, two new species from the Russian Far East and the U.S.A. are described on the basis of adult specimens. Parabelbella rusfareastensis sp. nov. differs from Parabelbella crenatosetosa Bulanova-Zachvatkina, 1967 by the smaller body size, the absence of propodolateral apophysis, direction of notogastral seta c1, and the mutual distance between notogastral setae c. Parabelbella pseudoinaequipes sp. nov. differs from Parabelbella inaequipes (Banks, 1947) by the presence of distinctly barbed notogastral setae la and lm and sparsely barbed setae c1, c2, lp, h3, shorter and thinner dorsal notogastral setae, anterior median ventral tubercle, and by distance between insertions of seta lm–lp. The redescription of P. inaequipes is presented, based on material from the U.S.A. The main morphological traits for this species are summarized. An identification key to known species of Parabelbella is provided. 


2006 ◽  
Vol 85 (9) ◽  
pp. 1066-1079 ◽  
Author(s):  
Sam Leary ◽  
Caroline Fall ◽  
Clive Osmond ◽  
Hermione Lovel ◽  
Doris Campbell ◽  
...  

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