Selection of skull morphological traits for sexual dimorphism analysis

HOMO ◽  
2012 ◽  
Vol 63 (4) ◽  
pp. 258-274 ◽  
Author(s):  
D. Psonak ◽  
B. Kwiatkowska
Keyword(s):  
Sexual Dimorphism ◽  
Morphological Traits ◽  
Selection Of

scholarly journals Supporting Physiological Trait for Indirect Selection for Grain Yield in Drought-Stressed Popcorn

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1510
Author(s):  
Samuel Henrique Kamphorst ◽  
Gabriel Moreno Bernardo Gonçalves ◽  
Antônio Teixeira do Amaral Júnior ◽  
Valter Jário de Lima ◽  
Kátia Fabiane Medeiros Schmitt ◽  
...  
Keyword(s):  
Grain Yield ◽  
Multiple Regression ◽  
Morphological Traits ◽  
Vegetation Index ◽  
Agronomic Traits ◽  
Indirect Selection ◽  
Leaf Angle ◽  
Water Restriction ◽  
Leaf Greenness ◽  
Selection Of

The identification of traits associated with drought tolerance in popcorn is a contribution to support selection of superior plants under soil water deficit. The objective of this study was to choose morphological traits and the leaf greenness index, measured on different dates, to estimate grain yield (GY) and popping expansion (PE), evaluated in a set of 20 popcorn lines with different genealogies, estimated by multiple regression models. The variables were divided into three groups: morpho-agronomic traits—100-grain weight (GW), prolificacy (PR), tassel length (TL), number of tassel branches, anthesis-silking interval, leaf angle (FA) and leaf rolling (FB); variables related to the intensity of leaf greenness during the grain-filling period, at the leaf level, measured by a portable chlorophyll meter (SPAD) and at the canopy level, calculated as the normalized difference vegetation index (NDVI). The inbred lines were cultivated under two water conditions: well-watered (WW), maintained at field capacity, and water stress (WS), for which irrigation was stopped before male flowering. The traits GY (55%) and PE (28%) were most affected by water restriction. Among the morpho-agronomic traits, GW and PR were markedly reduced (>10%). Under dry conditions, the FA in relation to the plant stalk tended to be wider, the FB curvature greater and leaf senescence accelerated (>15% at 22 days after male flowering). The use of multiple regression for the selection of predictive traits proved to be a useful tool for the identification of groups of adequate traits to efficiently predict the economically most important features of popcorn (GY and PE). The SPAD index measured 17 days after male flowering proved useful to select indirectly for GY, while, among the morphological traits, TL stood out for the same purpose. Of all traits, PR was most strongly related with PE under WS, indicating its use in breeding programs. The exploitation of these traits by indirect selection is expected to induce increments in GY and PE.

scholarly journals The dynamic of body and brain co-evolution

2021 ◽  
pp. 105971232199468
Author(s):  
Paolo Pagliuca ◽  
Stefano Nolfi
Keyword(s):  
Morphological Traits ◽  
The Body ◽  
Morphological Variations ◽  
And Control ◽  
Selection Of

We introduce a method that permits to co-evolve the body and the control properties of robots. It can be used to adapt the morphological traits of robots with a hand-designed morphological bauplan or to evolve the morphological bauplan as well. Our results indicate that robots with co-adapted body and control traits outperform robots with fixed hand-designed morphologies. Interestingly, the advantage is not due to the selection of better morphologies but rather to the mutual scaffolding process that results from the possibility to co-adapt the morphological traits to the control traits and vice versa. Our results also demonstrate that morphological variations do not necessarily have destructive effects on robots’ skills.

Aggression in female mammals: Is it really rare?

1999 ◽  
Vol 22 (2) ◽  
pp. 218-218 ◽  
Author(s):  
Paul F. Brain
Keyword(s):  
Sexual Dimorphism ◽  
Short Duration ◽  
Physical Aggression ◽  
Animal Studies ◽  
Human Values ◽  
Sexual Competition ◽  
Laboratory Rodents ◽  
Selection Of

The view that female mammals are more docile appears to arise in part from imposing human values on animal studies. Many reports of sexual dimorphism in physical aggression favouring the male in laboratory rodents appear to select circumstances where that expectation is supported. Other situations that favour the expression of conflict in females have been (until recently) relatively little studied. Although female rodents generally do not show the “ritualised” forms of conflict that characterise male sexual competition, they can use notably damaging strategies (especially if they are of short duration). Such considerations might weigh in the selection of strategies by our own species.

scholarly journals Selection of cassava (Manihot esculenta Crantz) genotypes based on agro-morphological traits in Angola

2019 ◽  
Vol 14 (7) ◽  
pp. 447-460
Author(s):  
Domingos Joao Afonso Sandra ◽  
Alberto da Silva Ledo Carlos ◽  
Franco Cunha Moreira Ricardo ◽  
da Silva Santos Vanderlei ◽  
Peixoto Borges Viviane ◽  
...  
Keyword(s):  
Manihot Esculenta ◽  
Morphological Traits ◽  
Manihot Esculenta Crantz ◽  
Selection Of

scholarly journals Habitat, Sexual and Allometric Influences on Morphological Traits of Intertidal Crabs

2020 ◽  
Author(s):  
P. Vermeiren ◽  
C. Lennard ◽  
C. Trave
Keyword(s):  
Sexual Selection ◽  
Sexual Dimorphism ◽  
Morphological Variation ◽  
Morphological Traits ◽  
Low Cost ◽  
Habitat Preferences ◽  
Mangrove Crab ◽  
Habitat Factors ◽  
Specific Factors ◽  
Claw Shape

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.

Multivariate analysis in mungbean [Vigna radiata (L.) Wilczek] to identify the genetic donors for pubescence and agro-morphological traits

2015 ◽  
Vol 38 (6) ◽  
Author(s):  
Chandra Mohan Singh ◽  
S. B. Mishra ◽  
Anil Pandey ◽  
Madhuri Arya
Keyword(s):  
Multivariate Analysis ◽  
Seed Yield ◽  
Morphological Traits ◽  
Branch Angle ◽  
High Contribution ◽  
Genotypic Cluster ◽  
Biological Yield ◽  
Total Divergence ◽  
Beak Length ◽  
Selection Of

The present investigation was conducted with 36 genotypes of mungbean on 26 agro-morphological traits including seed yield and pubescence traits to access the degree of divergence for mungbean improvement during <italic>zaid</italic> 2012. These mungbean genotypes were grouped into seven clusters. Cluster IV comprised of 14 genotypes, forming the largest cluster followed by cluster VI comprised eight genotypes, cluster I comprised seven genotypes and cluster II comprised four genotypes. Three clusters <italic>viz.</italic>, cluster III, V & VII formed mono genotypic cluster. All the pubescence traits contributed towards total divergence. Among the agro-morphological traits, high contribution towards total divergence was recorded for beak length, average intermodal length, primary branch angle with main stem, biological yield, seed yield and pods per cluster, indicated the possibility of selection of parent(s) for hybridization to manipulate the targeted trait(s) for mungbean improvement.

scholarly journals Artificial sexual selection alters allometry in the stalk-eyed fly Cyrtodiopsis dalmanni (Diptera: Diopsidae)

1993 ◽  
Vol 62 (3) ◽  
pp. 213-222 ◽  
Author(s):  
Gerald S. Wilkinson
Keyword(s):  
Sexual Selection ◽  
Sexual Dimorphism ◽  
Body Length ◽  
Sexually Dimorphic ◽  
Selected Lines ◽  
Variable Intensity ◽  
High Line ◽  
Cumulative Selection ◽  
Selection For ◽  
Selection Of

SummarySelection for increased and decreased ratio of eye span to body length was exerted on male stalk-eyed flies (Cyrtodiopsis dalmanni) from Malaysia using replicate selected and unselected lines. Response to selection was symmetrical. After 10 generations high line male eye span increased to 1·3 body lengths while low line male eye span declined to 1·1 body lengths. Realized heritabilities for eye span to body length ratio, estimated using regressions of deviations from unselected controls on cumulative selection differentials, were greater than zero for all four selected lines with average h2 = 0·35 + 0·06. The static linear allometric relationship between eye span and body length diverged between selected lines and rotated among selected line males in the same direction as among males in other sexually dimorphic diopsid species. Crosses between lines after 13 generations of selection indicate that the genes which influence relative eye span combine additively and do not exhibit sex linkage or maternal effects. The genetic correlation between the sexes, 0·29 + 0·05 as estimated by the regression of female on male change in eye span, did not prevent sexual dimorphism in eye span from diverging between lines. These results suggest that the exaggerated eye span of male C. dalmanni is maintained by natural selection opposing sexual selection rather than by lack of or asymmetry in additive genetic variation. Furthermore, the variation in sexual dimorphism for eye span-body length allometry observed among extant diopsid species is consistent with sexual selection of variable intensity acting on relative eye span.

Heads or tails? Sexual dimorphism in helodermatid lizards

2007 ◽  
Vol 85 (1) ◽  
pp. 92-98 ◽  
Author(s):  
C.M. Gienger ◽  
Daniel D. Beck
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Morphological Traits ◽  
Tail Length ◽  
Repeated Sequences ◽  
Analysis Of Covariance ◽  
Head Size ◽  
Heloderma Suspectum

We tested the hypothesis that helodermatid lizards (Gila monsters, Heloderma suspectum Cope, 1869, and beaded lizards, H. horridum (Wiegmann, 1829)) show sexual dimorphism in morphological traits related to male–male agonistic behaviors. Male–male combat in helodermatid lizards involves repeated sequences of ritualized grappling. Male Gila monsters use their heads in attempts to gain or maintain a superior position during repeated combat bouts that may last for hours. Pairs of fighting male beaded lizards form spectacular body arches, with abdomens adpressed and snouts, forelimbs, and tail tips contacting the ground. We measured body size, head size, and tail length in 208 preserved H. suspectum, and body size and tail length (but not head size) in 79 live H. horridum, then tested for sexual dimorphism using analysis of covariance. Male Gila monsters had proportionately larger heads than females but did not differ in tail length or body size. Male beaded lizards had proportionately longer tails than females and were larger in body size only when the largest individuals were included in the analysis. Differences in head dimensions (in H. suspectum) and tail length (in H. horridum) are likely the result of sexual selection acting through male–male agonistic behaviors in this unique lizard taxon.

scholarly journals Sex identification comparison of barn owls (Tyto alba javanica) using morphological features and molecular-based methods

2018 ◽  
Vol 12 (1) ◽  
pp. 47-54
Author(s):  
Shakinah Ravindran ◽  
Safwan Saufi ◽  
Wan Nur Amni ◽  
Intan Ishak ◽  
Noor Hisham Hamid ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Success Rate ◽  
Morphological Traits ◽  
Captive Breeding ◽  
Sex Identification ◽  
Molecular Sexing ◽  
Tyto Alba ◽  
Breeding Programs ◽  
Barn Owls ◽  
Captive Breeding Programs

Abstract Sexing of barn owls, Tyto alba javanica, using morphological traits has not been accurate enough due to ambiguous sexual dimorphism between sexes. This has been one of the major problems for the management of barn owls worldwide, especially for translocation and captive-breeding programs. In order to increase the success rate of sexing the barn owl, we compared the results of a molecular sexing method to six morphological traits for sexing the owls: the shape and colour of the facial disc, the colour of the throat area, the tail plumage, the colour of their tarsus, the back plumage, and the frequency of spotting on the chest and underside of the wings. The result of our comparison showed that sex identification using morphological traits had an accuracy of only 72.7%. Three of our samples were identified as females using morphological traits, but molecular sexing determined that these samples were males. We also used our results to determine the best morphological traits for sexing barn owls, and concluded that the best traits for morphological sexing are the frequency of spotting on the chest and underparts of barn owls (accuracy of 81.8%), as well as colour of the owls’ facial disc and throat area (accuracy of 63.6%).

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