scholarly journals Right-handed snakes: convergent evolution of asymmetry for functional specialization

2007 ◽  
Vol 3 (2) ◽  
pp. 169-173 ◽  
Author(s):  
Masaki Hoso ◽  
Takahiro Asami ◽  
Michio Hori
Keyword(s):  
Directional Asymmetry ◽  
Foraging Efficiency ◽  
Functional Specialization ◽  
Soft Body ◽  
Ecological Requirements ◽  
Feeding Experiments ◽  
Key Innovation ◽  
The Right ◽  
Snake Predators ◽  
Symmetry Break

External asymmetry found in diverse animals bears critical functions to fulfil ecological requirements. Some snail-eating arthropods exhibit directional asymmetry in their feeding apparatus for foraging efficiency because dextral (clockwise) species are overwhelmingly predominant in snails. Here, we show convergence of directional asymmetry in the dentition of snail-eating vertebrates. We found that snakes in the subfamily Pareatinae, except for non-snail-eating specialists, have more teeth on the right mandible than the left. In feeding experiments, a snail-eating specialist Pareas iwasakii completed extracting a dextral soft body faster with fewer mandible retractions than a sinistral body. The snakes failed in holding and dropped sinistral snails more often owing to behavioural asymmetry when striking. Our results demonstrate that symmetry break in dentition is a key innovation that has opened a unique ecological niche for snake predators.

scholarly journals PEMBERIAN HAK MILIK SATUAN RUMAH SUSUN DIATAS BEBERAPA HAK GUNA BANGUNAN PERORANGAN

2016 ◽  
Vol 1 (1) ◽  
pp. 101
Author(s):  
Masrofah Masrofah
Keyword(s):  
Land Rights ◽  
Housing Project ◽  
Legal Norms ◽  
Ecological Requirements ◽  
Technical Requirements ◽  
The Status ◽  
Implementation Guidelines ◽  
The Right ◽  
Administrative Sanctions ◽  
Ownership Rights

The objectives of this research are: (1) to study and analyze the status of ownership of a modern shopping center or mall upon some tenure individual rights. (2) to study and analyze the process of grantingownership rights for apartment unit.The method used in this research was normative, that is, a legal research which was based on legal materials obtained from literature that examined legal norms related to the issue of providing ownership rights for apartment units upon some building rights.Based on the results of research and discussion, it can be concluded as follows: (1) PT. G.U. that wanted to have its apartment units certified for ownership had constraints by the absence of  implementation guidelines of Law No. 16 of 1985 (now Act No. 20 of 2011). (2) The principle of horizontal separation is the opposite of attachment principle which states that buildings and plants are integrated to land. (3) In planning the development of apartment, developers of the construction should first pay attention to the layout of the area of city/ county. (4) The construction of a housing project must meet some requirements, they are: administrative requirements, technical requirements and ecological requirements. (5) Prior to certificate of ownership registration upon an apartment unit, certificate of land rights either in the form of property rights, the right to use the land for building and the right to use and manage the land. (6) In the Act of Apartment, if it does not meet the provisions of these rules, there are some sanctions to be given. These may be in the form of administrative sanctions or criminal verdicts such as fines and imprisonment.Keywords: Granting Rights, Certificate of Ownership Rights Unit of the Flats, Broking,Transitional sale, Land Consolidation. 

The relationship between asymmetry, size and unusual venation in honey bees (Apis mellifera)

2016 ◽  
Vol 106 (3) ◽  
pp. 304-313 ◽  
Author(s):  
S. Łopuch ◽  
A. Tofilski
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Directional Asymmetry ◽  
Right Wing ◽  
Wing Size ◽  
Large Variability ◽  
Normal Individuals ◽  
Wide Range ◽  
The Right ◽  
The Relationship

AbstractDespite the fact that symmetry is common in nature, it is rarely perfect. Because there is a wide range of phenotypes which differs from the average one, the asymmetry should increase along with deviation. Therefore, the aim of this study was to assess the level of asymmetry in normal individuals as well as in phenodeviants categorized as minor or major based on abnormalities in forewing venation in honey bees. Shape fluctuating asymmetry (FA) was lower in normal individuals and minor phenodeviants compared with major phenodeviants, whereas the former two categories were comparable in drones. In workers and queens, there were not significant differences in FA shape between categories. FA size was significantly lower in normal individuals compared with major phenodeviant drones and higher compared with minor phenodeviant workers. In queens, there were no significant differences between categories. The correlation between FA shape and FA size was significantly positive in drones, and insignificant in workers and queens. Moreover, a considerable level of directional asymmetry was found as the right wing was constantly bigger than the left one. Surprisingly, normal individuals were significantly smaller than minor phenodeviants in queens and drones, and they were comparable with major phenodeviants in all castes. The correlation between wing size and wing asymmetry was negative, indicating that smaller individuals were more asymmetrical. The high proportion of phenodeviants in drones compared with workers and queens confirmed their large variability. Thus, the results of the present study showed that minor phenodeviants were not always intermediate as might have been expected.

Effects of Habitat and Social Complexity on Brain Size, Brain Asymmetry and Dentate Gyrus Morphology in Two Octodontid Rodents

2016 ◽  
Vol 87 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Raúl Sobrero ◽  
Pedro Fernández-Aburto ◽  
Álvaro Ly-Prieto ◽  
Scarlett E. Delgado ◽  
Jorge Mpodozis ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Right Hemisphere ◽  
Brain Size ◽  
Natural Populations ◽  
Cell Number ◽  
Spatial Behavior ◽  
Population Variation ◽  
Directional Asymmetry ◽  
Male And Female ◽  
The Right

Navigational and social challenges due to habitat conditions and sociality are known to influence dentate gyrus (DG) morphology, yet the relative importance of these factors remains unclear. Thus, we studied three natural populations of O. lunatus (Los Molles) and Octodon degus (El Salitre and Rinconada), two caviomorph species that differ in the extent of sociality and with contrasting vegetation cover of habitat used. The brains and DG of male and female breeding degus with simultaneous information on their physical and social environments were examined. The extent of sociality was quantified from total group size and range area overlap. O. degus at El Salitre was more social than at Rinconada and than O. lunatus from Los Molles. The use of transects to quantify cover of vegetation (and other physical objects in the habitat) and measures of the spatial behavior of animals indicated animal navigation based on unique cues or global landmarks is more cognitively challenging to O. lunatus. During lactation, female O. lunatus had larger brains than males. Relative DG volume was similar across sexes and populations. The right hemisphere of male and female O. lunatus had more cells than the left hemisphere, with DG directional asymmetry not found in O. degus. Degu population differences in brain size and DG cell number seemed more responsive to differences in habitat than to differences in sociality. Yet, large-sized O. degus (but not O. lunatus) that ranged over larger areas and were members of larger social groups had more DG cells per hemisphere. Thus, within-population variation in DG cell number by hemisphere was consistent with a joint influence of habitat and sociality in O. degus at El Salitre.

scholarly journals Comparison of orbital asymmetries among some raptor species: “when size does not matter”

2020 ◽  
Vol 14 (1) ◽  
pp. 23-27
Author(s):  
Pere M. Parés-Casanova ◽  
Jordina Salas-Bosch
Keyword(s):  
Procrustes Analysis ◽  
Directional Asymmetry ◽  
Foraging Strategies ◽  
Tyto Alba ◽  
Geometric Morphometric ◽  
Bubo Bubo ◽  
Generalized Procrustes Analysis ◽  
Gyps Fulvus ◽  
Accipiter Nisus ◽  
The Right

Abstract A sample of 73 dry, well-preserved skulls was studied, representing various species of raptors with different foraging strategies. The sample included Accipiter nisus (n = 15), Buteo buteo (n = 13), Gyps fulvus (n = 24) and Neophron percnopterus (n = 5), Bubo bubo (n = 16) and Tyto alba (n = 2). Geometric morphometric methods were used to detect orbital asymmetries. On digital pictures of each skull side, a set of 16 semi-landmarks and two landmarks were located in order to describe the orbital ring. The variables were analysed based on Generalized Procrustes analysis. The morphometric data showed that the orbital asymmetry of raptors differed significatively between species, although directional asymmetry (e.g. left orbita systematically more developed than the right) appeared not to be correlated with orbital size. This indicates that larger orbitas do not lead to greater asymmetry. Differences between species should rather be explained by their foraging strategies and degree of visual obstruction in their natural environment.

scholarly journals Existence of mandibular directional asymmetry in the European wild boar (Sus scrofa Linnaeus, 1758)

2014 ◽  
Vol 31 (04) ◽  
pp. 228-232
Author(s):  
P. Parés-Casanova
Keyword(s):  
Sus Scrofa ◽  
Age Groups ◽  
The Body ◽  
The Other ◽  
Directional Asymmetry ◽  
Asymmetric Structure ◽  
Dorsal Aspect ◽  
European Wild Boar ◽  
Perfect Symmetry ◽  
The Right

Abstract Introduction and material and methods. We studied a sample of 37 dentulous dry mandibles from European wild board (Sus scrofa) and compared both the right and left sides in their dorsal aspect. To study the influence of age, the samples were grouped according to dental status: “subadults” (erupting 3rd M, n=22) and “adults” (fully erupted 3rd M, n=15). Individual levels of asymmetry were analysed from x- and y-coordinates of the 16 landmarks on the dorsal aspect of the mandible. Results. The analysis separated directional asymmetry (one side of the body with a larger character value than the other) and fluctuating asymmetry (small random deviations from perfect symmetry), which were both found to be significant. Conclusion. The condylar ramus was the most asymmetric structure for both age groups.

scholarly journals Ufocandona hannaleeae gen. et sp. nov. (Crustacea, Ostracoda) from an artesian well in Texas, USA

2017 ◽  
Author(s):  
Okan Külköylüoğlu ◽  
Mehmet Yavuzatmaca ◽  
Derya Akdemir ◽  
Benjamin F. Schwartz ◽  
Benjamin T. Hutchins
Keyword(s):  
New Genus ◽  
External Surface ◽  
Central Area ◽  
Body Parts ◽  
Soft Body ◽  
Diagnostic Characteristics ◽  
The Family ◽  
San Marcos ◽  
Asymmetric Shape ◽  
The Right

We describe a new genus, Ufocandona gen. nov. with its type species Ufocandona hannaleeae gen. et sp. nov., from an artesian well in San Marcos, Texas, USA. The new genus has diagnostic characteristics that distinguish it from other genera in Candonidae, including the asymmetric shape of the valves, the smooth central area on the external surface of the valves, the hexagonal ornamentations around the marginal ends of the carapace, the dense spines on the marginal edges of the right valve and the dorsal prolongation and tubercles seen from inside the ventral edges of the left valve. Additional differences in the soft body parts of the male and female (e.g., claw-like uropod, shape of hemipenis, long Y aesthetascs, two short or reduced exopods on antenna, reduced numbers of setae and segments on other extremities) distinguish the new genus from others in the family. The discovery of this species from a deep artesian well contributes important information to our understanding of groundwater species diversity in a biologically diverse aquifer where the ostracod fauna has been unstudied.

Sex Differences in Directional Asymmetry of Digit Length and its Effects on Sex Differences in Digit Ratio (2D:4D)

2008 ◽  
Vol 107 (2) ◽  
pp. 576-586 ◽  
Author(s):  
Martin Voracek ◽  
Denise Offenmüller ◽  
Stefan G. Dressler
Keyword(s):  
Sex Differences ◽  
Ring Finger ◽  
Digit Ratio ◽  
Directional Asymmetry ◽  
Leftward Bias ◽  
First Finding ◽  
The Right ◽  
Putative Marker ◽  
Prenatal Androgen ◽  
Digit Length

Patterns of directional asymmetry in the length of index and ring finger (2D and 4D) may be sexually differentiated. Martin, Puts, and Breedlove (2008) found leftward bias, i.e., both a longer 2D and 4D in the left than in the right hand, more frequently in men, whereas rightward bias occurred more frequently in women. Further, rightward vs leftward bias seemed a substantial source of variation in digit ratio (2D:4D), a putative marker for prenatal androgen levels. Given the generally small effects, unreplicable results, and inconsistent findings of 2D:4D research, these findings potentially are important as the type of directional digit asymmetry could moderate or obfuscate real associations between 2D:4D and target traits. Based on six samples totaling about 3,000 individuals, the present study replicated the first finding of Martin, Puts, and Breedlove (2008): leftward bias was more frequent among men and rightward bias more frequent among women. This sex effect was small. However, the present study did not replicate the second finding of Martin, et al. (2008): relative to participants' sex the contributions of leftward vs rightward asymmetry to individual variation in 2D:4D were smaller by orders of magnitude and not significant. Implications of these findings for 2D:4D research arc discussed.

scholarly journals Exotic predators are not better biocontrol agents: the harlequin ladybird is not the most voracious in Mexico

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12503
Author(s):  
Morelia Camacho-Cervantes ◽  
Wendy Mendoza-Arroyo ◽  
Daniela Arellano-Sánchez ◽  
Ek del-Val
Keyword(s):  
Native Species ◽  
Harmonia Axyridis ◽  
Biocontrol Agents ◽  
Foraging Efficiency ◽  
Generalist Predators ◽  
Harlequin Ladybird ◽  
Ecological Requirements ◽  
Exotic Invasive ◽  
Aphid Biocontrol ◽  
Eggs And Larvae

The use of exotic species for pest biocontrol has been a common pathway for introduction and dispersal of invasive species that may have undesired outcomes. Biocontrol agents are believed to be a less damaging alternative than pesticides, but some species may also prey on or parasitize native species or outcompete them for resources. The harlequin ladybird (Harmonia axyridis) is a well-known biocontrol agent originally from Asia that has established invasive populations in 59 countries around the globe. Harlequin ladybirds are generalist predators that in addition to pests prey on an array of different species including other coccinelids’ eggs and larvae. In Mexico, native ladybirds that share ecological requirements with harlequin ladybirds are at risk of being outcompeted and predated upon. The aim of our study was to compare the foraging efficiency of harlequin ladybirds against three species of native coccinelids when preying on aphids. We investigated the foraging behaviour of ladybirds alone and in pairs with a conspecific, a native heterospecific or an exotic heterospecific. We found that the native Cycloneda sanguinea was the species that consumed the most aphids, while Hippodamia convergens was the fastest to find and consume each aphid. Harlequin ladybirds and H. convergens consumed the same number of aphids while P. vittigera consumed less. Conspecific competition was stronger than heterospecific competition. We discuss the suitability of using the exotic invasive harlequin ladybird for aphid biocontrol in comparison with native coccinelids.

scholarly journals Laterality of Eye Use by Bottlenose (Tursiops truncatus) and Rough-Toothed (Steno bredanensis) Dolphins While Viewing Predictable and Unpredictable Stimuli

2020 ◽  
Vol 33 ◽  
Author(s):  
Malin K. Lilley ◽  
Amber J. de Vere ◽  
Deirdre B. Yeater
Keyword(s):  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Functional Specialization ◽  
Cetacean Species ◽  
Brain Hemispheres ◽  
Close Proximity ◽  
Eye Preference ◽  
Moving Stimulus ◽  
Steno Bredanensis ◽  
The Right

Laterality of eye use has been increasingly studied in cetaceans. Research supports that many cetacean species keep prey on the right side while feeding and preferentially view unfamiliar objects with the right eye. In contrast, the left eye has been used more by calves while in close proximity to their mothers. Despite some discrepancies across and within species, laterality of eye use generally indicates functional specialization of brain hemispheres in cetaceans. The present study aimed to examine laterality of eye use in bottlenose dolphins (Tursiops truncatus) and rough-toothed dolphins (Steno bredanensis) under managed care. Subjects were video-recorded through an underwater window while viewing two different stimuli, one predictable and static and the other unpredictable and moving. Bottlenose dolphins displayed an overall right-eye preference, especially while viewing the unpredictable, moving stimulus. Rough-toothed dolphins did not display eye preference while viewing stimuli. No significant correlations between degree of laterality and behavioral interest in the stimuli were found. Only for bottlenose dolphins were the degree of laterality and curiosity ratings correlated. This study extends research on cetacean lateralization to a species not extensively examined and to stimuli that varied in movement and degree of predictability. Further research is needed to make conclusions regarding lateralization in cetaceans.

scholarly journals Differential functional connectivity underlying asymmetric reward-related activity in human and nonhuman primates

2020 ◽  
Vol 117 (45) ◽  
pp. 28452-28462 ◽  
Author(s):  
Alizée Lopez-Persem ◽  
Léa Roumazeilles ◽  
Davide Folloni ◽  
Kévin Marche ◽  
Elsa F. Fouragnan ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Cognitive Processes ◽  
Nonhuman Primates ◽  
Rhesus Macaques ◽  
Reward Processing ◽  
Functional Specialization ◽  
Related Activity ◽  
Left And Right ◽  
Lesion Studies ◽  
The Right

The orbitofrontal cortex (OFC) is a key brain region involved in complex cognitive functions such as reward processing and decision making. Neuroimaging studies have reported unilateral OFC response to reward-related variables; however, those studies rarely discussed this observation. Nevertheless, some lesion studies suggest that the left and right OFC contribute differently to cognitive processes. We hypothesized that the OFC asymmetrical response to reward could reflect underlying hemispherical difference in OFC functional connectivity. Using resting-state and reward-related functional MRI data from humans and from rhesus macaques, we first identified an asymmetrical response of the lateral OFC to reward in both species. Crucially, the subregion showing the highest reward-related asymmetry (RRA) overlapped with the region showing the highest functional connectivity asymmetry (FCA). Furthermore, the two types of asymmetries were found to be significantly correlated across individuals. In both species, the right lateral OFC was more connected to the default mode network compared to the left lateral OFC. Altogether, our results suggest a functional specialization of the left and right lateral OFC in primates.

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