scholarly journals Patterns of divergence in the morphology of ceratopsian dinosaurs: sympatry is not a driver of ornament evolution

2018 ◽  
Vol 285 (1875) ◽  
pp. 20180312 ◽  
Author(s):  
Andrew Knapp ◽  
Robert J. Knell ◽  
Andrew A. Farke ◽  
Mark A. Loewen ◽  
David W. E. Hone
Keyword(s):  
Species Recognition ◽  
Morphological Characters ◽  
Sympatric Species ◽  
Phylogenetic Distance ◽  
Recognition Mechanism ◽  
Origin And Evolution ◽  
Ornament Evolution ◽  
And Function ◽  
Ornamental Traits ◽  
Ceratopsian Dinosaurs

Establishing the origin and function of unusual traits in fossil taxa provides a crucial tool in understanding macroevolutionary patterns over long periods of time. Ceratopsian dinosaurs are known for their exaggerated and often elaborate horns and frills, which vary considerably between species. Many explanations have been proposed for the origin and evolution of these ‘ornamental’ traits, from predator defence to socio-sexual dominance signalling and, more recently, species recognition. A key prediction of the species recognition hypothesis is that two or more species possessing divergent ornamental traits should have been at least partially sympatric. For the first time to our knowledge, we test this hypothesis in ceratopsians by conducting a comparison of the morphological characters of 46 species. A total of 350 ceratopsian cladistic characters were categorized as either ‘internal’, ‘display’ (i.e. ornamental) or ‘non display’. Patterns of diversity of these characters were evaluated across 1035 unique species pairs. Display characters were found to diverge rapidly overall, but sympatric species were not found to differ significantly in their ornamental disparity from non-sympatric species, regardless of phylogenetic distance. The prediction of the species recognition hypothesis, and thus the idea that ornamentation evolved as a species recognition mechanism, has no statistical support among known ceratopsians.

scholarly journals Sympatry drives colour and song evolution in wood-warblers (Parulidae)

2021 ◽  
Vol 288 (1942) ◽  
pp. 20202804
Author(s):  
Richard K. Simpson ◽  
David R. Wilson ◽  
Allison F. Mistakidis ◽  
Daniel J. Mennill ◽  
Stéphanie M. Doucet
Keyword(s):  
Related Species ◽  
Species Recognition ◽  
Sympatric Species ◽  
Signal Evolution ◽  
Wood Warblers ◽  
Mixed Support ◽  
Species Pairs ◽  
Song Divergence ◽  
Signal Diversity ◽  
Signal Divergence

Closely related species often exhibit similarities in appearance and behaviour, yet when related species exist in sympatry, signals may diverge to enhance species recognition. Prior comparative studies provided mixed support for this hypothesis, but the relationship between sympatry and signal divergence is likely nonlinear. Constraints on signal diversity may limit signal divergence, especially when large numbers of species are sympatric. We tested the effect of sympatric overlap on plumage colour and song divergence in wood-warblers (Parulidae), a speciose group with diverse visual and vocal signals. We also tested how number of sympatric species influences signal divergence. Allopatric species pairs had overall greater plumage and song divergence compared to sympatric species pairs. However, among sympatric species pairs, plumage divergence positively related to the degree of sympatric overlap in males and females, while male song bandwidth and syllable rate divergence negatively related to sympatric overlap. In addition, as the number of species in sympatry increased, average signal divergence among sympatric species decreased, which is likely due to constraints on warbler perceptual space and signal diversity. Our findings reveal that sympatry influences signal evolution in warblers, though not always as predicted, and that number of sympatric species can limit sympatry's influence on signal evolution.

scholarly journals Cuticular hydrocarbon profile for queen recognition in the termite Reticulitermes speratus

2021 ◽  
Author(s):  
Yuki Mitaka ◽  
Tadahide Fujita
Keyword(s):  
Cuticular Hydrocarbon ◽  
Gas Chromatography Mass Spectrometry ◽  
Reticulitermes Speratus ◽  
Recognition Mechanism ◽  
The Social ◽  
Queen Succession ◽  
Queen Recognition ◽  
And Function ◽  
Reproductive Division Of Labor ◽  
Reproductive Division

Abstract Chemical communication underlies the sophisticated colony organization of social insects. In these insects, cuticular hydrocarbons (CHCs) play central roles in nestmate, task, and caste recognition, which contribute to maintenance of the social and reproductive division of labor. Queen-specific CHCs reflect queen fertility status and function as a queen recognition pheromone, triggering aggregation responses around the queens. However, there are only a few studies about the royal recognition mechanism in termites, and particularly, no study has reported about queen-specific CHCs in the species using asexual queen succession (AQS) system, in which the primary queen is replaced by neotenic queens produced parthenogenetically. In this study, we identified the CHC pheromone for neotenic queen recognition in the AQS termite species Reticulitermes speratus. Gas chromatography-mass spectrometry analyses revealed that the relative amount of n-pentacosane was disproportionately greater in the CHC profiles of queens than in the CHC profiles of kings, soldiers, and workers. Furthermore, we investigated the cuticular chemicals of the queen aggregate workers; bioassays demonstrated that n-pentacosane shows a worker arrestant activity in the presence of workers’ cuticular extract. These results suggest that R. speratus workers identify whether each individual is a neotenic queen by recognizing the relatively higher ratio of n-pentacosane in the conspecific CHC background. Moreover, they suggest that termites have evolved queen recognition behavior, independently of social hymenopterans.

scholarly journals A Systematic Analysis of the Alpine Saxifrage Complex (Saxifragaceae) in the Canadian Arctic Islands Using Morphology and Chloroplast DNA Data

2004 ◽  
Vol 118 (3) ◽  
pp. 326 ◽  
Author(s):  
Caroline Healy ◽  
Lynn J. Gillespie
Keyword(s):  
Morphological Variability ◽  
Canadian Arctic ◽  
Principal Component ◽  
Distinct Species ◽  
Morphological Characters ◽  
Sympatric Species ◽  
Sensu Stricto ◽  
Morphological Data ◽  
Systematic Analysis ◽  
Site Analysis

The Saxifraga nivalis complex displays significant ecological, morphological and cytological variation. Most European studies suggest that the S. nivalis complex comprises two distinct species: Saxifraga nivalis sensu stricto and Saxifraga tenuis. However, the presence of intermediate morphotypes, inconsistencies in chromosomal counts and variability in morphological keys and descriptions have led to different taxonomic interpretations of the complex in North America. This study investigated the systematics of Canadian Arctic Island members of this complex from 157 specimens using 23 morphological characters. Principal component analysis of the morphological data revealed two adjacent clusters, corresponding to the two taxa and consistent with a close morphological similarity and the presence of hybrids. A preliminary restriction site analysis of five non-coding regions of the chloroplast genome, trnH-trnK, trnT-trnF, trnF-trnV, trnV-rbcL and rbcL-ORF106, was conducted using 21 restriction endonucleases. This analysis indicated a length difference between the trnT-trnF region of S. nivalis and that of S. tenuis, but no difference in restriction sites for any of the assayed regions. These results confirm that in the Canadian Arctic, the S. nivalis complex consists of two closely related, largely sympatric species, with notable morphological variability, and possible hybrids.

Guide to Native Bees of Australia

2018 ◽  
Author(s):  
Terry Houston
Keyword(s):  
Life Cycle ◽  
Natural History ◽  
Plant Material ◽  
Morphological Characters ◽  
Native Bees ◽  
Nest Architecture ◽  
Form And Function ◽  
Genus Level ◽  
Life Cycle Stages ◽  
And Function

Bees are often thought of as yellow and black striped insects that live in hives and produce honey. However, Australia’s abundant native bees are incredibly diverse in their appearance and habits. Some are yellow and black but others have blue stripes, are iridescent green or wasp-like. Some are social but most are solitary. Some do build nests with wax but others use silk or plant material, burrow in soil or use holes in wood and even gumnuts! A Guide to Native Bees of Australia provides a detailed introduction to the estimated 2000 species of Australian bees. Illustrated with stunning photographs, it describes the form and function of bees, their life-cycle stages, nest architecture, sociality and relationships with plants. It also contains systematic accounts of the five families and 58 genera of Australian bees. Photomicrographs of morphological characters and identification keys allow identification of bees to genus level. Natural history enthusiasts, professional and amateur entomologists and beekeepers will find this an essential guide.

scholarly journals Validating Morphometrics with DNA Barcoding to Reliably Separate Three Cryptic Species of Bombus Cresson (Hymenoptera: Apidae)

Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 669
Author(s):  
Joan Milam ◽  
Dennis E. Johnson ◽  
Jeremy C. Andersen ◽  
Aliza B. Fassler ◽  
Desiree L. Narango ◽  
...  
Keyword(s):  
Cryptic Species ◽  
Dna Barcoding ◽  
Morphological Characters ◽  
Sympatric Species ◽  
Bumble Bees ◽  
Hair Color ◽  
Width Ratio ◽  
Large Size ◽  
Morphometric Methods ◽  
The Status

Despite their large size and striking markings, the identification of bumble bees (Bombus spp.) is surprisingly difficult. This is particularly true for three North American sympatric species in the subgenus Pyrobombus that are often misidentified: B. sandersoni Franklin, B. vagans Smith B. perplexus Cresson. Traditionally, the identification of these cryptic species was based on observations of differences in hair coloration and pattern and qualitative comparisons of morphological characters including malar length. Unfortunately, these characteristics do not reliably separate these species. We present quantitative morphometric methods to separate these species based on the malar length to width ratio (MRL) and the ratios of the malar length to flagellar segments 1 (MR1) and 3 (MR3) for queens and workers, and validated our determinations based on DNA barcoding. All three measurements discriminated queens of B. sandersoni and B. vagans with 100% accuracy. For workers, we achieved 99% accuracy by combining both MR1 and MR3 measurements, and 100% accuracy differentiating workers using MRL. Moreover, measurements were highly repeatable within and among both experienced and inexperienced observers. Our results, validated by genetic evidence, demonstrate that malar measurements provide accurate identifications of B. vagans and B. sandersoni. There was considerable overlap in the measurements between B. perplexus and B. sandersoni. However, these species can usually be reliably separated by combining malar ratio measurements with other morphological features like hair color. The ability to identify bumble bees is key to monitoring the status and trends of their populations, and the methods we present here advance these efforts.

Mechanisms of heterospecific recognition in avian mobbing calls

2003 ◽  
Vol 51 (6) ◽  
pp. 577 ◽  
Author(s):  
Frances R. Johnson ◽  
Elisabeth J. McNaughton ◽  
Courtney D. Shelley ◽  
Daniel T. Blumstein
Keyword(s):  
Sympatric Species ◽  
Dominant Frequency ◽  
Playback Experiments ◽  
Broad Bandwidth ◽  
Call Recognition ◽  
Allopatric Species ◽  
Interspecific Recognition ◽  
And Function

Some birds emit special calls, referred to as mobbing calls, when they detect a predator in their area. These calls are easily localisable and function to rally other individuals to help chase out a threatening intruder. Interestingly, individuals may respond to the mobbing calls of other sympatric species. To understand the mechanism underlying interspecific recognition it is essential to determine whether birds also respond to the mobbing calls of allopatric species. If, as has been suggested, learning is important for call recognition, then calls from allopatric species should not evoke mobbing. If, however, there are intrinsic (and possibly convergent) characteristics of mobbing calls, then novel calls from allopatric species should evoke mobbing. We conducted two playback experiments with apostlebirds (Struthidea cinera, Family Corcoracidae), Australian mud-nesters, to understand mechanisms underlying mobbing-call recognition. The first demonstrated that allopatric mobbing calls could elicit a response significantly greater than control stimuli, but less than that elicited by playback of conspecific calls. The second demonstrated that the dominant frequency was critical for eliciting mobbing, rather than the commonly assumed broad bandwidth. Taken together, these results suggest that experience with a particular species' call is not essential to elicit mobbing; rather, intrinsic aspects of the calls themselves may explain heterospecific recognition.

scholarly journals The limits of evolutionary convergence in sympatry: reproductive interference and developmental constraints leading to local diversity in aposematic signals

2021 ◽  
Author(s):  
Ludovic Maisonneuve ◽  
Charline Smadi ◽  
Violaine Llaurens
Keyword(s):  
Mate Recognition ◽  
Sympatric Species ◽  
Reproductive Interference ◽  
Phylogenetic Distance ◽  
Trait Divergence ◽  
Local Diversity ◽  
Mutualistic Interaction ◽  
Evolutionary Convergence ◽  
Aposematic Signals ◽  
Imperfect Mimicry

ABSTRACTMutualistic interaction between defended species is a striking case of evolutionary convergence in sympatry, driven by the increased protection against predators brought by mimicry. However, such convergence is often limited: sympatric defended species frequently display different or imperfectly similar warning traits. The phylogenetic distance between sympatric species may indeed prevent evolution towards the exact same signal. Moreover, warning traits are also implied in mate recognition, so that trait convergence might result in heterospecific courtship and mating. Here, we investigate the strength and direction of convergence in warning trait in defended species with different ancestral traits, using a mathematical model. We specifically determine the effect of phenotypic distances among ancestral traits of converging species, and costs of heterospecific sexual interactions on imperfect mimicry and trait divergence. Our analytical results confirm that reproductive interference limits the convergence of warning trait, leading to either imperfect mimicry or complete divergence. More surprisingly, our model pinpoints that reproductive interference can change the direction of convergence depending on the relative species densities. We also show that reproductive interference can generate imperfect mimicry only between species with different ancestral traits. Our model therefore highlights that convergence triggered by Müllerian mimicry not only depends on relative defence levels, but that relative species densities, heterospecific sexual interactions and ancestral traits interfere in the direction and strength of convergence between species.

scholarly journals Yaravirus: A novel 80-nm virus infectingAcanthamoeba castellanii

2020 ◽  
Vol 117 (28) ◽  
pp. 16579-16586 ◽  
Author(s):  
Paulo V. M. Boratto ◽  
Graziele P. Oliveira ◽  
Talita B. Machado ◽  
Ana Cláudia S. P. Andrade ◽  
Jean-Pierre Baudoin ◽  
...  
Keyword(s):  
Major Capsid Protein ◽  
Amino Acid Level ◽  
Three Dimensional ◽  
Genomic Diversity ◽  
Phylogenetic Distance ◽  
Preliminary Assessment ◽  
Dna Viruses ◽  
Origin And Evolution ◽  
Viral Genomes ◽  
Jelly Roll

Here we report the discovery of Yaravirus, a lineage of amoebal virus with a puzzling origin and evolution. Yaravirus presents 80-nm-sized particles and a 44,924-bp dsDNA genome encoding for 74 predicted proteins. Yaravirus genome annotation showed that none of its genes matched with sequences of known organisms at the nucleotide level; at the amino acid level, six predicted proteins had distant matches in the nr database. Complimentary prediction of three-dimensional structures indicated possible function of 17 proteins in total. Furthermore, we were not able to retrieve viral genomes closely related to Yaravirus in 8,535 publicly available metagenomes spanning diverse habitats around the globe. The Yaravirus genome also contained six types of tRNAs that did not match commonly used codons. Proteomics revealed that Yaravirus particles contain 26 viral proteins, one of which potentially representing a divergent major capsid protein (MCP) with a predicted double jelly-roll domain. Structure-guided phylogeny of MCP suggests that Yaravirus groups together with the MCPs ofPleurochrysisendemic viruses. Yaravirus expands our knowledge of the diversity of DNA viruses. The phylogenetic distance between Yaravirus and all other viruses highlights our still preliminary assessment of the genomic diversity of eukaryotic viruses, reinforcing the need for the isolation of new viruses of protists.

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