scholarly journals Phylogenetic Patterns in Mouth Posture and Echolocation Emission Behavior of Phyllostomid Bats

2021 ◽  
Vol 9 ◽  
Author(s):  
Gloria Gessinger ◽  
Rachel Page ◽  
Lena Wilfert ◽  
Annemarie Surlykke ◽  
Signe Brinkløv ◽  
...  
Keyword(s):  
High Speed ◽  
Feeding Habits ◽  
Phylogenetic Signal ◽  
Ancestral State ◽  
Sound Emission ◽  
Behavioral Differences ◽  
Open Mouth ◽  
Echolocation Calls ◽  
Sister Clade ◽  
Emission Behavior

While phyllostomid bats show an impressive range of feeding habits, most of them emit highly similar echolocation calls. Due to the presence of an often prominent noseleaf, it has long been assumed that all phyllostomids emit echolocation calls exclusively through the nostrils rather than through the mouth. However, photo evidence documents also phyllostomid bats flying with an opened mouth. We hypothesized that all phyllostomid species emit echolocation calls only through the nostrils and therefore fly consistently with a closed mouth, and that observations of an open mouth should be a rare and random behavior among individuals and species. Using a high-speed camera and standardized conditions in a flight cage, we screened 40 phyllostomid species. Behavior varied distinctly among the species and mouth posture shows a significant phylogenetic signal. Bats of the frugivorous subfamilies Rhinophyllinae and Carolliinae, the nectarivorous subfamilies Glossophaginae and Lonchophyllinae, and the sanguivorous subfamily Desmodontinae all flew consistently with open mouths. So did the animalivorous subfamilies Glyphonycterinae, Micronycterinae and Phyllostominae, with the notable exception of species in the omnivorous genus Phyllostomus, which consistently flew with mouths closed. Bats from the frugivorous subfamily Stenodermatinae also flew exclusively with closed mouths with the single exception of the genus Sturnira, which is the sister clade to all other stenodermatine species. Further, head position angles differed significantly between bats echolocating with their mouth closed and those echolocating with their mouths opened, with closed-mouth phyllostomids pointing only the nostrils in the direction of flight and open-mouth phyllostomids pointing both the nostrils and mouth gape in the direction of flight. Ancestral trait reconstruction showed that the open mouth mode is the ancestral state within the Phyllostomidae. Based on the observed behavioral differences, we suggest that phyllostomid bats are not all nasal emitters as previously thought and discuss possible reasons. Further experiments, such as selectively obstructing sound emission through nostrils or mouth, respectively, will be necessary to clarify the actual source, plasticity and ecological relevance of sound emission of phyllostomid bats flying with their mouths open.

scholarly journals Ancestry and evolution of seasonal migration in the Parulidae

2011 ◽  
Vol 279 (1728) ◽  
pp. 610-618 ◽  
Author(s):  
Benjamin M. Winger ◽  
Irby J. Lovette ◽  
David W. Winkler
Keyword(s):  
Phylogenetic Signal ◽  
Rapid Change ◽  
Large Family ◽  
Seasonal Migration ◽  
Ancestral State ◽  
Migratory Behaviour ◽  
Wood Warbler ◽  
Wood Warblers ◽  
History Of ◽  
The Tropics

Seasonal migration in birds is known to be highly labile and subject to rapid change in response to selection, such that researchers have hypothesized that phylogenetic relationships should neither predict nor constrain the migratory behaviour of a species. Many theories on the evolution of bird migration assume a framework that extant migratory species have evolved repeatedly and relatively recently from sedentary tropical or subtropical ancestors. We performed ancestral state reconstructions of migratory behaviour using a comprehensive, well-supported phylogeny of the Parulidae (the ‘wood-warblers’), a large family of Neotropical and Nearctic migratory and sedentary songbirds, and examined the rates of gain and loss of migration throughout the Parulidae. Counter to traditional hypotheses, our results suggest that the ancestral wood-warbler was migratory and that losses of migration have been at least as prevalent as gains throughout the history of Parulidae. Therefore, extant sedentary tropical radiations in the Parulidae represent losses of latitudinal migration and colonization of the tropics from temperate regions. We also tested for phylogenetic signal in migratory behaviour, and our results indicate that although migratory behaviour is variable within some wood-warbler species and clades, phylogeny significantly predicts the migratory distance of species in the Parulidae.

Kinematic analysis of a novel feeding mechanism in the brook trout Salvelinus fontinalis (Teleostei: Salmonidae): behavioral modulation of a functional novelty

2001 ◽  
Vol 204 (22) ◽  
pp. 3905-3916
Author(s):  
Christopher P. J. Sanford
Keyword(s):  
Kinematic Analysis ◽  
Brook Trout ◽  
High Speed ◽  
Salvelinus Fontinalis ◽  
Univariate Analysis ◽  
Head Length ◽  
Power Stroke ◽  
Maximum Displacement ◽  
Open Mouth ◽  
Feeding Mechanism

SUMMARY The tongue-bite apparatus (TBA) of salmonids represents an impressive novel feeding mechanism. The TBA consists of a set of well-developed teeth on the dorsal surface of the anterior hyoid (basihyal) and an opposing set of teeth on the roof of the mouth (vomer). A kinematic analysis of behaviors associated with the TBA in the brook trout Salvelinus fontinalis was performed using high-speed video (250 frames s–1). Two distinct behaviors were identified, raking and open-mouth chewing. Univariate analysis demonstrated that these behaviors were significantly different from one another. The power stroke of raking is characterized by significantly greater neurocranial elevation (raking, 36°; open-mouth chewing, 16°) and retraction of the pectoral girdle (raking, 0.85 cm or 21 % of head length; open-mouth chewing, 0.41 cm or 10 % of head length). Open-mouth chewing is characterized predominantly by dorso-ventral excursions of the anterior hyoid (open-mouth chewing, 0.26 cm; raking, 0.14 cm). Raking is significantly shorter in duration (mean 49 ms) than open-mouth chewing (mean 77 ms). When presented with three different types of prey (crickets, fish or worms), Salvelinus fontinalis showed no variation in raking behavior, indicating that raking is highly stereotyped. In contrast, when feeding on worms, Salvelinus fontinalis modulated open-mouth chewing behavior with shorter durations to maximum displacement (at least 20 ms shorter than for either fish or cricket), although the magnitude of displacements did not vary. The reasons for the shorter duration of displacement variables while feeding on worms remains unclear. During post-capture processing behaviors in Salvelinus fontinalis, the magnitude of displacement variables is highly variable between individuals, but temporal patterns are not. This study characterizes two novel post-capture feeding behaviors and modulation of those behaviors in salmonids.

Ancestral state, phylogenetic signal and convergence among anuran distress calls

2018 ◽  
Vol 274 ◽  
pp. 1-5 ◽  
Author(s):  
Lucas Rodriguez Forti ◽  
Camila Zornosa-Torres ◽  
Rafael Márquez ◽  
Luís Felipe Toledo
Keyword(s):  
Phylogenetic Signal ◽  
Ancestral State ◽  
Distress Calls

scholarly journals Emission Modes in Electrospray Thrusters Operating with High Conductivity Ionic Liquids

Aerospace ◽  
2020 ◽  
Vol 7 (10) ◽  
pp. 141
Author(s):  
Nolan M. Uchizono ◽  
Adam L. Collins ◽  
Anirudh Thuppul ◽  
Peter L. Wright ◽  
Daniel Q. Eckhardt ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Steady State ◽  
High Speed ◽  
Liquid Propellant ◽  
Long Distance ◽  
Flow Rates ◽  
Extraction Voltage ◽  
Wide Range ◽  
Emission Behavior ◽  
Definition Of

Electrospray thruster life and mission performance are strongly influenced by grid impingement, the extent of which can be correlated with emission modes that occur at steady-state extraction voltages, and thruster command transients. Most notably, we experimentally observed skewed cone-jet emission during steady-state electrospray thruster operation, which leads to the definition of an additional grid impingement mechanism that we termed “tilted emission”. Long distance microscopy was used in conjunction with high speed videography to observe the emission site of an electrospray thruster operating with an ionic liquid propellant (EMI-Im). During steady-state thruster operation, no unsteady electrohydrodynamic emission modes were observed, though the conical meniscus exhibited steady off-axis tilt of up to 15°. Cone tilt angle was independent over a wide range of flow rates but proved strongly dependent on extraction voltage. For the geometry and propellant used, the optimal extraction voltage was near 1.6 kV. A second experiment characterized transient emission behavior by observing startup and shutdown of the thruster via flow or voltage. Three of the four possible startup and shutdown procedures transition to quiescence within ∼475 μs, with no observed unsteady modes. However, during voltage-induced thruster startup, unsteady electrohydrodynamic modes were observed.

scholarly journals Fossil hominin shoulders support an African ape-like last common ancestor of humans and chimpanzees

2015 ◽  
Vol 112 (38) ◽  
pp. 11829-11834 ◽  
Author(s):  
Nathan M. Young ◽  
Terence D. Capellini ◽  
Neil T. Roach ◽  
Zeresenay Alemseged
Keyword(s):  
Tool Use ◽  
High Speed ◽  
Common Ancestor ◽  
Modern Human ◽  
Last Common Ancestor ◽  
Ancestral State ◽  
Evolutionary Trajectories ◽  
Parsimonious Model ◽  
And Function ◽  
Fossil Hominin

Reconstructing the behavioral shifts that drove hominin evolution requires knowledge of the timing, magnitude, and direction of anatomical changes over the past ∼6–7 million years. These reconstructions depend on assumptions regarding the morphotype of the Homo–Pan last common ancestor (LCA). However, there is little consensus for the LCA, with proposed models ranging from African ape to orangutan or generalized Miocene ape-like. The ancestral state of the shoulder is of particular interest because it is functionally associated with important behavioral shifts in hominins, such as reduced arboreality, high-speed throwing, and tool use. However, previous morphometric analyses of both living and fossil taxa have yielded contradictory results. Here, we generated a 3D morphospace of ape and human scapular shape to plot evolutionary trajectories, predict ancestral morphologies, and directly test alternative evolutionary hypotheses using the hominin fossil evidence. We show that the most parsimonious model for the evolution of hominin shoulder shape starts with an African ape-like ancestral state. We propose that the shoulder evolved gradually along a single morphocline, achieving modern human-like configuration and function within the genus Homo. These data are consistent with a slow, progressive loss of arboreality and increased tool use throughout human evolution.

scholarly journals Reconstructing the ancestral phenotypes of great apes and humans (Homininae) using subspecies-level phylogenies

2019 ◽  
Author(s):  
Keaghan J Yaxley ◽  
Robert A Foley
Keyword(s):  
Dna Sequences ◽  
Phenotypic Variation ◽  
Common Ancestor ◽  
Phylogenetic Signal ◽  
Great Apes ◽  
Last Common Ancestor ◽  
Ancestral State ◽  
Great Ape ◽  
Subspecies Level ◽  
African Great Apes

Abstract Owing to their close affinity, the African great apes are of interest in the study of human evolution. Although numerous researchers have described the ancestors we share with these species with reference to extant great apes, few have done so with phylogenetic comparative methods. One obstacle to the application of these techniques is the within-species phenotypic variation found in this group. Here, we leverage this variation, modelling common ancestors using ancestral state reconstructions (ASRs) with reference to subspecies-level trait data. A subspecies-level phylogeny of the African great apes and humans was estimated from full-genome mitochondrial DNA sequences and used to implement ASRs for 14 continuous traits known to vary between great ape subspecies. Although the inclusion of within-species phenotypic variation increased the phylogenetic signal for our traits and improved the performance of our ASRs, whether this was done through the inclusion of subspecies phylogeny or through the use of existing methods made little difference. Our ASRs corroborate previous findings that the last common ancestor of humans, chimpanzees and bonobos was a chimp-like animal, but also suggest that the last common ancestor of humans, chimpanzees, bonobos and gorillas was an animal unlike any extant African great ape.

scholarly journals Much more than a clasp: evolutionary patterns of amplexus diversity in anurans

2020 ◽  
Vol 129 (3) ◽  
pp. 652-663 ◽  
Author(s):  
Juan D Carvajal-Castro ◽  
Yelenny López-Aguirre ◽  
Ana María Ospina-L ◽  
Juan C Santos ◽  
Bibiana Rojas ◽  
...  
Keyword(s):  
Morphological Traits ◽  
Sexual Size Dimorphism ◽  
Phylogenetic Signal ◽  
Evolutionary Relationships ◽  
Behavioural Ecology ◽  
Ancestral State ◽  
Evolutionary Patterns ◽  
Evolutionary Transitions ◽  
Size Dimorphism ◽  
Reproductive Modes

Abstract The evolution and diversification of animal reproductive modes have been pivotal questions in behavioural ecology. Amphibians present the highest diversity of reproductive modes among vertebrates, involving various behavioural, physiological and morphological traits. One such feature is the amplexus, which is the clasp or embrace of males on females during reproduction and is found almost universally in anurans. Hypotheses about the origin of amplexus are limited and have not been tested thoroughly, nor have they taken into account evolutionary relationships in most comparative studies. However, these considerations are crucial to an understanding of the evolution of reproductive modes. Here, using an evolutionary framework, we reconstruct the ancestral state of amplexus in 685 anuran species. We investigate whether the type of amplexus has a strong phylogenetic signal and test whether sexual size dimorphism could have influenced amplexus type or male performance while clasping females. Overall, we found evidence of ≥34 evolutionary transitions in amplexus type across anurans. We found that amplexus type exhibits a high phylogenetic signal and that amplexus type does not evolve in association with sexual size dimorphism. We discuss the implications of our findings for the diversity of amplexus types across anurans.

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