Symmetry and Human Facial Attractiveness

Symmetry may act as a marker of phenotypic and genetic quality and is preferred during mate selection in a variety of species. Measures of human body symmetry correlate with attractiveness, but studies manipulating human face images report a preference for asymmetry. These results may reflect unnatural feature shapes and changes in skin textures introduced by image processing. When the shape of facial features is varied (with skin textures held constant), increasing symmetry of face shape increases ratings of attractiveness for both male and female faces. These findings imply facial symmetry may have a positive impact on mate selection in humans.     

Nonlinear Phenomena Conveying Body Size Information and Improving Attractiveness of the Courtship Calls in the Males of Odorrana tormota

Nonlinear phenomena are commonly shown in the vocalization of animals and exerts different adaptive functions.Although some studies have pointed out that nonlinear phenomena can enhance the individual identification of male Odorrana tormota,whether the nonlinear phenomena play a specific role in the sexual selection of O.tormota remain unclear.Here we presented evidence that there was a significant negative correlation(Pearson:n=30,r=0.65,P<0.001)between the nonlinear phenomena content and snout-vent length in the male O.tormota,and two-choice amplexus experiments showed that female O.tormota preferred male with smaller body size containing higher nonlinear phenomena content in its calls.Phonotaxis experiments also revealed that females preferred calls with higher nonlinear phenomena content.Additionally,compared to the calls with lower nonlinear phenomena content and higher fundamental frequency,there was shorter response time in phonotactic behaviour of female induced by the calls with higher nonlinear phenomena content and lower fundamental frequency.We argue that the nonlinear phenomena content in the calls of male O.tormota can convey its body size information and may provide important clues for female frogs in darkened surroundings to identify males’body size during mate choice,meanwhile,higher nonlinear phenomena content in males’calls may increase the attractiveness of males to females.The results of this study provide confirmation that,for O.tormota,nonlinear phenomena have specific function in mate choice.     

Triglycerides in the Human Kidney Cortex: Relationship with Body Size

Obesity is associated with increased risk for kidney disease and uric acid nephrolithiasis, but the pathophysiological mechanisms underpinning these associations are incompletely understood. Animal experiments have suggested that renal lipid accumulation and lipotoxicity may play a role, but whether lipid accumulation occurs in humans with increasing body mass index (BMI) is unknown. The association between obesity and abnormal triglyceride accumulation in non-adipose tissues (steatosis) has been described in the liver, heart, skeletal muscle and pancreas, but not in the human kidney. We used a quantitative biochemical assay to quantify triglyceride in normal kidney cortex samples from 54 patients undergoing nephrectomy for localized renal cell carcinoma. In subsets of the study population we evaluated the localization of lipid droplets by Oil Red O staining and measured 16 common ceramide species by mass spectrometry. There was a positive correlation between kidney cortex trigyceride content and BMI (Spearman R = 0.27, P = 0.04). Lipid droplets detectable by optical microscopy had a sporadic distribution but were generally more prevalent in individuals with higher BMI, with predominant localization in proximal tubule cells and to a lesser extent in glomeruli. Total ceramide content was inversely correlated with triglycerides. We postulate that obesity is associated with abnormal triglyceride accumulation (steatosis) in the human kidney. In turn, steatosis and lipotoxicity may contribute to the pathogenesis of obesity-associated kidney disease and nephrolithiasis.     

柳江人身体大小和形状——体重、身体比例及相对脑量的分析

发现于广西柳江的更新世晚期人类化石除1具完整的头骨外,还包含有右侧髋骨、骶骨、两段股骨及若干件椎骨。根据各方面的特征分析,初步认定这些化石属于同一个体。这一有利条件为我们比较准确地获取与该个体身体大小和形状有关的指标数据提供了可能。本文通过对柳江人头骨及复原骨盆的测量,计算了柳江人的身高、体重、身体比例、相对脑量等。在此基础上分析了柳江人的身体大小和形状。本研究发现:柳江人化石所代表的个体具有适应温暖气候环境的纤细型身体比例,代表相对脑量的EQ指数5.602大于金牛山、山顶洞等中国更新世中、晚期化石人类,而与包括港川人在内的更新世末期及现代人类的EQ指数接近。柳江人体重52.0kg小于金牛山、山顶洞、尼安德特人等生活在高纬度地区的化石人类,而与港川、非洲的KNM-ER3883、KNM-ER3733等生活在温暖环境的古人类接近。作者认为这些发现除说明柳江人生活的气候环境外,还提示柳江人身体大小、比例及相对脑量与更新世末期及现代人类接近。     

Beer Consumption Increases Human Attractiveness to Malaria Mosquitoes

Background

Malaria and alcohol consumption both represent major public health problems. Alcohol consumption is rising in developing countries and, as efforts to manage malaria are expanded, understanding the links between malaria and alcohol consumption becomes crucial. Our aim was to ascertain the effect of beer consumption on human attractiveness to malaria mosquitoes in semi field conditions in Burkina Faso.

Methodology/Principal Findings

We used a Y tube-olfactometer designed to take advantage of the whole body odour (breath and skin emanations) as a stimulus to gauge human attractiveness to Anopheles gambiae (the primary African malaria vector) before and after volunteers consumed either beer (n = 25 volunteers and a total of 2500 mosquitoes tested) or water (n = 18 volunteers and a total of 1800 mosquitoes). Water consumption had no effect on human attractiveness to An. gambiae mosquitoes, but beer consumption increased volunteer attractiveness. Body odours of volunteers who consumed beer increased mosquito activation (proportion of mosquitoes engaging in take-off and up-wind flight) and orientation (proportion of mosquitoes flying towards volunteers'' odours). The level of exhaled carbon dioxide and body temperature had no effect on human attractiveness to mosquitoes. Despite individual volunteer variation, beer consumption consistently increased attractiveness to mosquitoes.

Conclusions/Significance

These results suggest that beer consumption is a risk factor for malaria and needs to be integrated into public health policies for the design of control measures.     

Body Size and Termite Evolution

Termites are a monophyletic lineage within the paraphyletic Blattaria, with xylophagous cockroaches in the genus Cryptocercus as sister group. Given this ancestry, termite divergence involved a substantial leap in body plans, as they are pale, fragile, and miniaturized relative to most cockroaches. Here I suggest that the evolutionary transition to an altricial morphotype in termites is grounded in the economics of utilizing a wood diet, and occurred via a series of sequential steps associated with modifications in social behavior. The chief benefit of an altricial morphotype is suggested to be nitrogen made available by decreasing individual body size and by dispensing with a heavy, melanized cuticle. The primary costs lie in increased vulnerability to environment hazards, including predators, pathogens, and desiccation. Termites tipped the evolutionary scale via cooperative behaviors that mitigate the cost or amplify the benefit of a small, fragile morphotype, and were present in rudimentary form in their cockroach relatives. These include building behavior, cooperative feeding, allogrooming, and most notably, trophallaxis. It was the directed circulation of nitrogenous reserves via trophallactic feeding among units of the superorganism rather than their progressive storage in a large, heavily armored body that was the foundation of termite evolutionary success.     

福建漳平奇和洞新石器时代早期人类身体大小

身高、体重、颅容量等是反映人类身体大小,探讨人类体质特征、生长发育水平及营养健康状况的重要指标。本文采用公式推算法,对2011年在福建漳平奇和洞遗址出土的、距今约9500年的奇和洞II号女性个体的身高、体重、颅容量等身体大小特征进行了研究。结果显示,奇和洞II号的身高和体重约为160.3cm和59.9kg,在新石器时代成年女性个体中属于较高水平,同时高于福建地区现代成年女性的平均水平;颅容量约为1369m L,在新石器时代成年女性个体中处于中间水平。奇和洞II号较好的身体特征发育,提示处于更新世晚期向全新世过渡这一时期的奇和洞人可能具有较好的营养状况;与新、旧石器时代各组的比较显示,这一时期我国华南地区古人类身体大小、形状特征已经形成;我国南、北方地区人群身高、体重差异已经出现。     

Body Size Distribution of the Dinosaurs

The distribution of species body size is critically important for determining resource use within a group or clade. It is widely known that non-avian dinosaurs were the largest creatures to roam the Earth. There is, however, little understanding of how maximum species body size was distributed among the dinosaurs. Do they share a similar distribution to modern day vertebrate groups in spite of their large size, or did they exhibit fundamentally different distributions due to unique evolutionary pressures and adaptations? Here, we address this question by comparing the distribution of maximum species body size for dinosaurs to an extensive set of extant and extinct vertebrate groups. We also examine the body size distribution of dinosaurs by various sub-groups, time periods and formations. We find that dinosaurs exhibit a strong skew towards larger species, in direct contrast to modern day vertebrates. This pattern is not solely an artefact of bias in the fossil record, as demonstrated by contrasting distributions in two major extinct groups and supports the hypothesis that dinosaurs exhibited a fundamentally different life history strategy to other terrestrial vertebrates. A disparity in the size distribution of the herbivorous Ornithischia and Sauropodomorpha and the largely carnivorous Theropoda suggests that this pattern may have been a product of a divergence in evolutionary strategies: herbivorous dinosaurs rapidly evolved large size to escape predation by carnivores and maximise digestive efficiency; carnivores had sufficient resources among juvenile dinosaurs and non-dinosaurian prey to achieve optimal success at smaller body size.     

Visual Diet versus Associative Learning as Mechanisms of Change in Body Size Preferences

Systematic differences between populations in their preferences for body size may arise as a result of an adaptive ‘prepared learning’ mechanism, whereby cues to health or status in the local population are internalized and affect body preferences. Alternatively, differences between populations may reflect their ‘visual diet’ as a cognitive byproduct of mere exposure. Here we test the relative importance of these two explanations for variation in body preferences. Two studies were conducted where female observers were exposed to pictures of high or low BMI women which were either aspirational (healthy, attractive models in high status clothes) or non-aspirational (eating disordered patients in grey leotards), or to combinations thereof, in order to manipulate their body-weight preferences which were tested at baseline and at post–test. Overall, results showed good support for visual diet effects (seeing a string of small or large bodies resulted in a change from pre- to post-test whether the bodies were aspirational or not) and also some support for the associative learning explanation (exposure to aspirational images of overweight women induced a towards preferring larger bodies, even when accompanied by equal exposure to lower weight bodies in the non-aspirational category). Thus, both influences may act in parallel.     

Racial Differences in Selection of Ideal Body Size by Adolescent Females

Cultural differences may partially account for the fact that more black women than white women are overweight in the United States. This study measured perceptions of ideal body size among 93 black and 80 white females, 14–17 years old, who were randomly selected from three public high schools in a southeastern state. The subjects' height and weight were measured along with their estimates of their mother's body size, weight control attitudes, and demographic variables . Blacks preferred a significantly larger body sue than whites when asked to select ideal body size (p=0.045). Subjects who estimated their mother's size to be larger, also selected a larger ideal body size (p=.047). Those who perceived themselves as too fat were more likely to skip meals to help control their weight, compared with those who perceived themselves as normal or too thin (p=.003). Approximately 30% of the sample was overweight or obese. There were not significant racial differences in weight or BMI . These results suggest that overweight is more acceptable among black females than among white females and may help explain why more black females are obese .     

Vocal and Facial Attractiveness Judgments of Children, Adolescents and Adults: the Ontogeny of Mate Choice

Physical traits are thought to be used as indicators of mate quality, allowing individuals to select mates most likely to help them bear the fittest offspring. As the capacity for human sexual behaviour emerges at puberty, we investigated whether adult‐like judgments of the relative attractiveness of opposite‐sex individuals also arise at puberty. Following previous research, we focussed on facial and vocal attractiveness, which are known to be used in human mate choice and to carry concordant information regarding mate quality. Here we show that males with more attractive faces have more attractive voices as judged by female adults and adolescents, but not by female children. This suggests that cues of facial and vocal attractiveness provide similar information, but that awareness of these cues does not develop fully until reproductive capability, when mate choice judgments become relevant. Adolescents’ judgments also mirrored those of adults in that, like adults, they preferred lower‐pitched male voices, and as a group made concordant judgments about facial attractiveness. However, they did not make similarly concordant judgments about vocal attractiveness, suggesting that a further period of maturation and learning is required to fully develop optimal judgments for mate choice.     

Body Size and Morph as Drivers of Copulation Duration in a Male Dimorphic Damselfly

Copulation duration is often highly variable within and among species. Here, we explore the roles of body size, male morph, morph frequency, and alternative reproductive tactics to explain copulation duration in the damselfly Paraphlebia zoe. P. zoe has two male morphs (pigmented or hyaline wings) which differ in reproductive tactics (territorial or non‐territorial behaviors). We also analyze the effects of season as the frequencies of both morphs tend to vary along the reproductive season. In the first non‐experimental year, we found that the relationship between body size and copulation duration depended on the time of year. Early in the season, body size positively correlated with copulation duration, while late in the year, body size negatively correlated with copulation duration. In the second experimental year (when we reversed the frequency of male morphs in the middle of the season: making pigmented males less frequent than hyaline males), size influenced copulation duration as well as morph – body size positively correlated with copulation duration, and hyaline males mated for longer than pigmented males. Contrary to our prediction, changes to the relative abundances of morphs did not influence copulation duration. Hyaline males may be under selection for longer copulation durations to compensate for their reduced access to females, as long copulations potentially lead to more rival sperm to be removed from the female sperm storage organs and/or increased mate guarding. We do not discard, however, other explanations that drive variation in copulation duration such as cryptic female choice and/or predation.     

Fisher's Axiom and the Body Size of Animals

What is here called Fisher's axiom states that all large mutations are deleterious, and the consequence of this is the generally accepted Darwinian notion that all evolutionary progress must have occurred through the accumulation of small mutational steps. We have in the present paper tested the postulate that one parameter, namely, the body size (weight or volume) does not vary in this way, but rather in steps which are powers of two, up to or down, as the case may be. The outcome of our analysis is that this hypothesis is corroborated with fair significance for certain, randomly selected, groups of living and extinct animals. The consequences of this observation are briefly discussed.     

Body Size and Reproductive Tactics in Varanid lizards

Body size and female reproduction in the water adult females larger than 500 mm SVL and 32 adult males Ledong, Hainan under permit to our laboratory in Hainan monitor lizard （Varanus salvator） were studied. Forty-two larger than 400 mm SVL were donated by local people in in 2013 and 2014. The largest male and female measured 745 and 755 mm SVL, respectively. The mean SVL was greater in adult females than in adult males. Males had larger heads （head width） than females of the same SVL. The smallest reproductive female in our sample was 565 mm SVL. Females produced a single clutch of 17.1 （10-23） pliable-shelled eggs per breeding season stretching from mid-June and mid-September. Clutch size and clutch mass were all positively related to female SVL. However, there was no significant linear relationship between egg mass and female SVL. Larger females generally produced more eggs, and thus heavier clutches than did smaller ones. There was no significant linear relationship between relative clutch mass and female SVL. Phylogenetic generalized least squares （PGLS） analysis, accounting for phylogenetic relationships, showed that clutch size was positively correlated with mean maternal SVL in varanid lizards. PGLS analysis showed that phylogenetic relationships did not affect clutch （or/and egg） mass and the SVL although there were significant linear relationship between clutch （or/and egg） mass and mean maternal SVL. Therefore, we could draw some general conclusions about the body size and reproductive tactics in varanid lizards that larger females generally produced more eggs, larger eggs and thus heavier clutches than did smaller ones.     

Diversity and Evolution of Body Size in Fishes

The diversity of body sizes observed among species of a clade is a combined result of microevolutionary processes (i.e. natural selection and genetic drift) that cause size changes within phylogenetic lineages, and macroevolutionary processes (i.e. speciation and extinction) that affect net rates of diversification among lineages. Here we assess trends of size diversity and evolution in fishes (non-tetrapod craniates), employing paleontological, macroecological, and phylogenetic information. Fishes are well suited to studies of size diversity and evolution, as they are highly diverse, representing more than 50% of all living vertebrate species, and many fish taxa are well represented in the fossil record from throughout the Phanerozoic. Further, the frequency distributions of sizes among fish lineages resemble those of most other animal taxa, in being right-skewed, even on a log scale. Using an approach that measures rates of size evolution (in darwins) within a formal phylogenetic framework, we interpret the shape of size distributions as a balance between the competing forces of diversification, pushing taxa away from ancestral values, and of conservation, drawing taxa closer to a central tendency. Within this context we show how non-directional mechanisms of evolution (i.e. passive diffusion processes) can produce an hitherto unperceived bias to larger size, when size is measured on the conventional log scale. These results demonstrate how the interpretation of macroecological datasets can be enriched from an historical perspective, and document the ways in which macroevolutionary and microevolutionary processes may be decoupled in the production of size diversity.