Spelling suggestions: "subject:"fluctuating asymmetry"" "subject:"fluctuating assymmetry""
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Fliuktuojanti kaukolės asimetrija bebrų (Castor fiber L.) populiacijoje Lietuvoje / Fluctuating cranium asymmetry in local populations of beaver (castor fiber l.) in lithuaniaBrasiūnaitė, Rita 08 September 2009 (has links)
Fliuktuojanti asimetrija (FA) - tai asimetrijos forma, susijusi su atsitiktiniais nukrypimais nuo tikslios kūno simetrijos. Nustatyta, jog gyvūnų populiacijose FA lygis koreliuoja su tam tikrų aplinkos stresų, kuriuos individai patiria savo ontogenetiniame vystymesi, lygiu (Zakharov, 1989; Palmer, 1994). Tokiu būdu, FA gali būti aplinkos kokybės indikatoriumi: kuo mažiau asimetriškų individų populiacijoje, tuo optimalesnė aplinka. Dabartinė bebrų populiacija Lietuvoje yra susiformavusi iš keleto genetiškai skirtingų plitimo židinių. Galima daryti prielaidą, jog skirtingos genetinės struktūros populiacijos gali nevienodai reaguoti į aplinkos stresus. FA lygis buvo tiriamas dešimtyje upių baseinų lokaliose bebrų populiacijose. FA lygis buvo vertinamas pagal 5 metrinius ir 46 nemetrinius bebrų kaukolės požymius. Pirmuoju atveju FA lygis vertintas pagal skirtumų tarp kairės ir dešinės kaukolės pusių dispersiją, antruoju – pagal asimetriškų individų procentą populiacijoje. Tirtų individų imtis – 562. Tyrimų metu buvo nustatyta, kad mažiausiai FA lygis priklauso nuo bebrų lyties pagal nemetrinius kaukolės požymius. Daugiausiai – nuo individų amžinės struktūros. Mažiausiai asimetriški yra jaunikliai (FA lygis siekė 34%), dižiausias FA lygis nustatytas lytiškai subrendusių individų imtyje (46%). Taip pat nustatyta, kad juodą kailį turintys individai yra asimetriškesni už rudą kailį turinčius individus, o individai su dantų vystymosi anomalijomis yra asimetriškesni už dantų anomalijų... [toliau žr. visą tekstą] / Fluctuating asymmetry (FA) it is a form of asymmetry which is related with random deviations off accurate body symmetry. It has been stated, that in animal populations a level of FA correlates with a level of environmental stresses which occure during animals ontogenetic development (Zakharov, 1989; Palmer, 1994). Therefore FA could be an indicator of environmental quality: the less asymmetric individuals in population, the better environment. Present beaver population is formed from several genetically different places in Lithuania. So it could be that genetically different local populations can react to environmental stresses differently. Level of FA in ten river watersheds in local beaver populations has been investigated. Level of FA in skulls of beavers according to 5 metric and 46 non metric traits has been assessed. Level of FA has been assessed according to differences between left and right skull side dispersion in first case, in second case – according to percentage of asymmetric individuals in population. Number of investigated individuals is 562. It has been stated, that level of FA depends on beaver sex at least according to non metric skull traits. Mostly it depends on age structure of individuals. At least asymmetric there are juveniles (level of FA was 34%), great level of FA has been stated in adults (46%). Also it has been stated, that beavers who have black skin are more asymmetric than brown skin ones and individuals who have tooth anomalies are more... [to full text]
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Evaluating the Developmental Instability-Sexual Selection Hypothesis in the Fruit Fly, Drosophila bipectinata (Diptera: Drosophilidae)Hamilton, Brooke January 2010 (has links)
No description available.
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Pre and post natal facial development in South Africans of African descentAdebesin, Abduljalil Adetola 04 March 2013 (has links)
No description available.
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Sportininkų ir nesportuojančiųjų kūno simetriškumo rodiklių sąsaja su kairiarankiškumu/dešiniarankiškumu / Relationship between handedness (hand preference) and functional (a)symmetry in athletes and sedentariesGicevičius, Marius 18 June 2008 (has links)
Tyrimo problema Mūsų visuomenėje neskiriama pakankamai dėmesio kairiarankiams, jų problemos yra ignoruojamos, apie ką kalbama ir užsienio autorių darbuose, tačiau iki šiol nėra pakankamai aiškios skirtingo abiejų žmonių rankų veiksnumo priežastys, sąsajos ir padariniai.
Tyrimo tikslas. Ištirti, kaip priklauso dešiniarankiškumo/kairiarankiškumo laipsnis nuo fizinio aktyvumo lygio ir pobūdžio (t.y. ištirti dešiniarankiškumo ir kairiarankiškumo paplitimą tarp skirtingų sporto šakų atletų) ir nustatyti dešiniarankiškumo/kairiarankiškumo laipsnio sąsajas su rankų funkciniai ir anatominiais rodikliais.
Darbo uždaviniai.
1. Anketavimo metodu nustatyti ir palyginti skirtingų sporto šakų atletų dešiniarankiškumo/kairiarankiškumo laipsnį.
2. Palyginti skirtingų sporto šakų atletų skirtingų rankų matmenų ir funkcinę asimetriją bei palyginti skirtingų sporto šakų ir grupių sportininkų rankų matmenų ir funkcinę asimetriją tarpusavyje.
3. Ištirti koreliacinę dešiniaranki���kumo/kairiarankiškumo laipsnio priklausomybę su rankų funkciniu ir matmenų asimetriškumu.
Rezultatai. Iš visų tirtų 126 vyrų kairiarankių buvo 6,3 procento. Iš tirtų 33 kontrolinės grupės (nesportuojančiųjų) asmenų nė vieno pagal Bryden klausimyną nenustatėme esančio kairiarankiu. Tiek jėgos, tiek ištvermės sporto šakose buvo daugiau vyrų, kuriems dešinė ranka yra patogi rečiau/mažiau nei kairė (p<0,05). Tarp žaidėjų ir nesportuojančiųjų reikšmingas dešiniarankiškumo/kairiarankiškumo skirtumas nenustatytas (p>0,05)... [toliau žr. visą tekstą] / In the our days society, still not enough attention is paid at left-handed persons‘ problems, and we still lack the knowledge on the reasons and outcomes of the so-called hand preference, or handedness. Thus the aim of our study was to evaluate how the degree of handedness is dependent on the level and type of physical activity, and we studied three groups of athletes from different sports as well as sedentaries by standard questionnaire on hand preference as well as standard physical tests and anthropometry in order to determine the predilection of left/right-handedness among athletes from various different sports, and to obtain some better knowledge on the relationship of hand-preference with the functional and anthropometrical (a)symmetry of the hands.
The results obtained revealed that among 126 of studied males 6.3 percent were clearly left-handed, but no one of the 33 control sedentaries was. Clear tendency was evident that among athletes of strength and endurance activities left-handedness was more expressed. This was not the case in ball-game athletes’ group. All groups when studies separately as well as one big group did not showed any signs of hand-size asymmetry, though some of the results of the tests for hand function were distinct between hands, the same in overall group and in four groups studied separately. These were handgrip strength, juggling with two baseballs, and maximal rate of hand and arm movements. The correlation between handedness score and... [to full text]
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Bilateral Asymmetry in Incisors: Implications for Miocene Hominoid Species DiagnosisDavis, Candace Ann 01 August 2011 (has links)
AN ABSTRACT OF THE DISSERTATION OF CANDACE A. DAVIS, for the Doctor of Philosophy Degree in ANTHROPOLOGY, presented on March 31, 2011, at Southern Illinois University at Carbondale. TITLE: BILATERAL ASYMMETRY IN INCISORS: IMPLICATIONS FOR MIOCENE HOMINOID SPECIES DIAGNOSIS MAJOR PROFESSOR: Dr. Robert S. Corruccini The primary purpose of this dissertation is to show how knowledge of variation and asymmetry in incisor antimeric pairs of living great ape genera can be utilized as a "yardstick" for pairwise comparisons of isolated Miocene ape incisors from the two genera Kenyapithecus and Equatorius . The research was designed to help determine whether these fossil teeth could be reliably sorted into one or more than one genera. Both metric and morphological data for each class of incisor were recorded for Kenyapithecus and Equatorius , and resampling was performed to determine the significance of variation (p<.05) for each of 12 traits. Intraindividual antimeric differences in three genera of extant great apes were compared with interspecimen differences between Equatorius and Kenyapithecus. Pairwise comparisons using resampling sorted out which traits showed intraindividual significant variation and which could be used to discriminate between the two fossil genera under consideration. Based on these results, one can cautiously conclude the two fossil species within these genera are not different enough to justify placing them in two different genera.
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Bilateral Asymmetry in Chickens of Different Genetic backgroundsYang, Aiming 04 June 1998 (has links)
The dissertation consists of a series of experiments conducted to study developmental stability of various genetic stocks at different stages in the life cycle. The primary measures of stability were type and degree of asymmetry of bilateral traits and heterosis.
Higher relative asymmetry (RA), which was defined as (|L-R| / [(L+R)/2]) x 100, was observed in lines of White Leghorns selected 23 generations for high or low antibody response to sheep red blood cells than in their F1 crosses. The bilateral traits were 39-day shank length and length and weight of the first primary wing feather. Shank length was again measured on day 49 while body, heart, shank, and lung weights and ceca lengths were obtained on day 56. Heterosis was positive for organ sizes and negative for degree of RA.
Shank length and diameter, weight and length of the first primary wing feather, and distance between the junction of maxilla and mandibles and auditory canal (face length) were used to classify bilateral types and measure RA in six genetic stocks. The stocks were the S23 generation of White Leghorn lines selected for high or low antibody response to SRBC, sublines where selection had been relaxed for eight generations, and reciprocal crosses of the selected lines. Differences were found among all stocks for the traits measured. Rankings among traits for RA in descending order were face length, shank diameter, feather weight, and shank and feather lengths. The RA of shank and feather lengths did not differ from each other. The mean RA of the five traits was higher for the two selected lines than the crosses between them. The RAs of the two lines where selection had been relaxed was similar to that of selected lines.
In a line of White Rocks selected 39 generations for low eight-week body weight, bilateral traits measured were shank length and diameter, face length, and weight and length of the first primary wing feather of females at 240 days of age. The RAs of individuals that had not commenced egg production by 245 days of age were similar to those that had entered lay. In both cases, these RAs were higher than those of a subline in which selection had been relaxed for four generations.
Broiler sire lines had higher RA than dam lines for lung weight at hatch. Heterosis of RAs suggested superior homeostasis in F1 crosses than in the sire lines.
Based on populations studied, it may be concluded that RAs were trait specific with the RA of shank length being lower (0 < RA < 2%) than lung weight which was 10% or higher regardless of genetic background. The types of bilateral asymmetry exhibited although less consistent, still had consistency such that feather weight and ceca weight exhibited antisymmetry across different stocks. Length and width of shank and weight of lung, were generally of fluctuating asymmetry.
Heart:lung ratios differed among genetic stocks. In White Leghorns, lungs from late embryonic development to 25 days after hatch were heavier in a line which had heavier juvenile body weight than in one with lower juvenile body weight. In commercial broilers, heart:lung ratios at hatch were lower and thus inferior in parental lines than in their F1 crosses. / Ph. D.
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Assessments of phenotypic variations and variability as a tool for understanding evolutionary processes in echinoidsSchlüter, Nils 14 April 2016 (has links)
No description available.
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Estruturação populacional, variações fenotípicas e estudos morfométricos em Apis mellifera (Hymenoptera: Apidae) no Brasil / Populational structuration, phenotypic variations and morphometric studies in Apis mellifera (Hymenoptera: Apidae) in Brazil.Nunes, Lorena Andrade 07 March 2012 (has links)
Apis mellifera é uma espécie de abelha bastante estudada sob diferentes perspectivas, tanto em pesquisas básicas como aplicadas. Possui uma natureza singular associada não só a interesses econômicos como produção de cera, mel, própolis, geléia real, pólen, mas também, por seu potencial agrícola como polinizador. Esta espécie tem sido alvo de muitos estudos morfométricos, principalmente pela sua importância ecológica, pela sua grande capacidade de adaptação, sua ampla distribuição e por serem capazes de se estabelecer eficientemente em diversos ambientes. A morfometria geométrica permite uma análise rigorosa da variação da forma de uma determinada estrutura em organismos de diversos tamanhos, principalmente utilizando métodos de estatística multivariada, além de ser capaz de avaliar a instabilidade no desenvolvimento de um organismo. O presente trabalho teve como objetivo estudar as variações da forma e tamanho em asas e corbículas de operárias de Apis mellifera, provenientes das 5 regiões geográficas do Brasil, utilizando análises morfogeométricas. A existência de padrões de variação de forma e tamanho das abelhas africanizadas no Brasil obtidos há 16 anos em estudo clássico realizado por Diniz-Filho e Malaspina, possibilitou uma análise espaço-temporal comparativa com os resultados obtidos utilizando recursos tecnológicos atuais para a avaliação de dados morfométricos, bem como, verificar por meio das análises de assimetria flutuante a plasticidade fenotípica no tamanho e forma da asa e corbícula dessa espécie, possibilitou ainda, avaliar se condições adversas relacionadas às ações antrópicas influenciam no aumento de desvios na simetria bilateral desses caracteres morfológicos. Foi realizada uma amostragem abrangendo as 5 regiões geográficas do Brasil, pela forma das asa e análises multivariadas verificou-se que existe um padrão geográfico entre as populações de Apis mellifera no Brasil (P < 0,001). Essas variações geográficas podem ser devidas à grande extensão territorial, além da possível associação das diferenças entre ecorregiões. Verificou-se, também, a presença de assimetria flutuante na forma das asas e das corbículas de Apis mellifera em todas as populações estudadas, porém, na análise multivariada e assimetria do tamanho não obteve significância em algumas populações, constatando-se que para estudo de assimetria e distribuição populacional a forma da asa e das corbículas é a análise mais indicada e que apresenta maior precisão. / Apis mellifera is bee specie very studied under different perspectives, as for basic studies to applied ones. They have a singular nature, not only associated to economic issues as wax, honey, propolis, royal jelly and pollen production, but also for their agricultural potential as pollinators. This specie has been long aimed for morphometric studies, because of its ecological importance, easy capacity of adaptation, large distribution and for being able of efficient establishment in diverse environments. The geometric morphometric allows rigorous analyses in shape variation of a given structure in organism of diverse sizes, especially when using multivariate statistics methods, enabling the evaluation of instability in the development of an organism. The present study aim the variations of shape and size in wings and pollen basket from workers of Apis mellifera, acquired at 5 geographic regions of Brazil, using morphogeometric analyses. The existence of variation patters in shape and size of Africanized bees in Brazil, obtained 16 years ago in classic study made by Diniz-Filho and Malaspina, made possible a comparative spatialtemporal analyses with the results obtained in this study, using updated technology resources for evaluation of morphometric data, as well as the phenotypic plasticity exam of size and shape in wings and pollen basket of this specie, using fluctuating asymmetric analysis, and evaluate if diverse conditions made by anthropomorphic actions has influence on the deviation increase among bilateral symmetry of this morphological characters. The sample was made including 5 geographic regions of Brazil. By the wings size shape and multivariate analyses, it was verified the existence of a geographic pattern among Brazilian Apis mellifera populations (P< 0,001). Those geographical variations may be caused due to the big territorial expansion, alongside with the possible association of different ecoregions. It was also verified floating asymmetric in the shape of wings and pollen basket from Apis mellifera in all studied populations, however, in the multivariate analyses the asymmetry in shape was not significant in some populations, showing that, for studies of asymmetry and populational distribution, the shape of wings and pollen basket is the most indicated and precise analyses.
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Quantitative genetics of skull shape in Soay sheep (Ovis aries) using geometric morphometricsDamasceno Silva, Elis January 2016 (has links)
Analysing variation of skull shape in wild populations can give us an insight into evolutionary processes. By looking into patterns of morphological variation within populations, we can extrapolate and make assumptions on the patterns of variation on higher taxonomic levels. In this thesis, I collected data on skull shape of a wild population of Soay sheep using geometric morphometrics methods. I applied a multitude of quantitative genetics and geometric morphometrics methods to explore the factors behind the evolution of skull shape. I analysed several aspects of skull shape, including integration and modularity, predicted response to hypothetical selection, estimates of natural selection, presence of heterochrony, and fluctuating asymmetry (FA) in an ecological and genetic point of view. I found low levels of integration in the Soay sheep skull, along with the presence of two modules: face and neurocranium. Both the levels of integration and the pattern of modularity were found across different origins of variation, individual, genetic and developmental (FA), indicating a strong correspondence between levels. Although genetic integration is not strong, I found that most of hypothetical selection regimes result in as much correlated selection as direct selection responses. But the nose region has shown to be quite independent from the rest of the skull, with a retraction of the nose causing almost no correlated changes. Selection on skull shape is comparatively strong in the Soay sheep. The skull shape selected for in males differs from the shape selected in females. Males are selected to have wider nasal bones along with longer, flatter braincase, whereas females are selected towards narrower nasal bones, along with smaller braincases. But selection is not the only factor influencing changes in skull shape. Changes in temperature along the past 30 years are causing a change in developmental timing in Soay sheep, causing a decrease in overall body size in the population. And I found that skull shape is also being affected, thus indicating that this population might be undergoing heterochronic processes. Finally, I found that factors such as vegetation quality, parasite load and breeding success are related to FA levels, whereas population density and climate are not. I also found no significant heritability nor dominance in FA of skull shape. Overall, this thesis certainly contributes to the understanding of evolution of skull shape in natural populations. By successfully combining quantitative genetics and geometric morphometrics methods, I was able to tackle questions about the evolution of complex shapes, and give valuable insights into this still underexplored field.
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A Study of Habitat Selection and Fluctuating Asymmetry of <em>Amybstoma tigrinum</em> at Henderson Island Wildlife Management Area in Jefferson County TN.Ogle, Christopher Scott 01 May 2011 (has links)
Studies were conducted on a population of tiger salamanders, Ambystoma tigrinum, at Henderson Island Wildlife Management Area in Jefferson County, TN. Tests were conducted to locate the nonbreeding habitat of the salamanders and to detect any difference in fluctuating asymmetry (FA) between larval populations in a large, permanent pond and an ephemeral wetland. Drift fences were installed with pitfall traps at selected locations around each pond to determine nonbreeding habitat use by adults. Most adult salamanders were found using a blackberry (Rubus sp.) dominated old-field, a grassy field, and a shrub-grass mix field, which were all adjacent to the ponds. No statistical difference in FA between the 2 ponds.
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