Women's evaluations of other women's natural body odor depend on target's fertility status

A large research literature indicates that men perceive women as more attractive when they are at high fertility than at low fertility within the ovulatory cycle. However, it remains unclear whether women also perceive women as more attractive at high fertility. This study examined women's ratings of samples of natural body odor collected from naturally-cycling women at high and low fertility within the cycle and from hormonal contraceptive-using women at mid-cycle. Like men, women rated naturally-cycling women's high-fertility scent samples as more attractive than their low-fertility samples. Women rated hormonal contraceptive (HC) users' scent samples as more attractive than naturally-cycling women's high- and low-fertility samples, though the difference between HC and high-fertility samples was statistically significant only when raters were treated as the unit of analysis. These findings reveal a potentially important role for scent communication in women's perceptions of other women and are consistent with the notion that the ovulatory cycle could influence women's interactions with one another. The findings also highlight the need for rigorous investigations of the possible impacts of hormonal contraception on women's attractiveness and social relationships with other women.     

Men's voice pitch influences women's trusting behavior

Women tend to trust men with low-pitched voices as political leaders but trust men with high-pitched voices in mating scenarios. To elucidate the role of pitch in perceptions of trust, we used a one-decision variant of the trust game in which female participants were given the choice to trust males to divide the money, or to end the game, taking a smaller than equal sum. Male receivers were simulated using pitch-manipulated voice recordings. Women trusted raised pitch voices more than lowered pitch voices. These results suggest that although people with masculine voices are entrusted to lead our governments, people with masculine voices are not trusted to divide up financial resources equitably on a personal level.     

On the ecological and evolutionary significance of storage in clonal plants

Environmental heterogeneity has received wide attention in clonal plant research over the last decade. Most studies have focussed on the effects of spatial variation in environmental conditions on the performance of ramets and genets, while the effects of temporal heterogeneity have only occasionally been studied. As a consequence, our current knowledge about functional responses of clonal plants to habitat patchiness is biased towards spatial aspects of environmental heterogeneity. Nevertheless, temporal changes in biotic and abiotic conditions do occur in most natural habitats, and they are very likely to affect plant growth and performance, and to create positive selection pressures on traits that can buffer plants against unfavorable consequences of this variability. Storage of resources is a widespread phenomenon in clonal plant species. Typical clonal structures such as stolons, rhizomes and hibernacles serve as storage organs. However, the ecologic significance of storage in clonal plant structures remains partly unclear. We suggest that the lack of understanding with respect to resource storage in clonal plants be related to our poor knowledge of ecologic implications of temporal habitat heterogeneity in natural environments. Resource storage can be understood as a safety measure against temporal changes in the growing conditions of plants. This paper summarizes existing information about the ecologic relevance of storage in clonal plants and it tries to develop a framework for further investigation of resource storage as a strategy to enhance the performance of clonal plants in temporally variable environments.     

中国哺乳动物多样性

中国哺乳动物区系有鲜明的特色:有青藏高原分布的特有种属,有第三纪孑遗动物——大熊猫科和白鱀豚科,世界一半以上的鼠兔科动物为中国特有种,中国还是世界有蹄类最丰富的国家。新世纪以来,世界哺乳动物分类体系发生了变化,中国也发现一批哺乳动物新种和新记录种。因此,有必要对中国哺乳动物多样性名录进行及时更新和完善。我们在《中国生物多样性红色名录·哺乳动物卷》的编研中,对中国哺乳动物的目级阶元采用在系统发育基因组学已经取得一致意见的方案;在科及以下阶元以《中国哺乳动物种与亚种分类名录与分布大全》和Mammal Species of the World:A Taxonomic and Geographic Reference(第3版)的分类系统为基础,有蹄类的分类采用Ungulate Taxonomy分类系统;收集整理了中国(包括台湾地区)所有哺乳动物资料,增加了截至2015年3月31日学术期刊发表的中国哺乳动物新种和新记录种,通过会议评审和通讯评审,调整了一些物种的名称和分类地位,确定了《中国哺乳动物名录(2015)》。该名录收录了中国现有哺乳动物12目55科245属673种,其中,新种18种(包括11种最近发现的或利用分子生物学方法确定的、尚有争议的新种)、新记录种18种、60个亚种提升为种。根据研究结果和专家意见,剔除了52种哺乳动物。此外,中国分类学家对新版名录中的20种啮类(Glires)的分类地位持不同意见,这些种类需要进一步研究。以《中国哺乳动物名录(2015)》收录的中国哺乳动物种数与其他国家比较,中国哺乳动物种数超过IUCN(2014)报道的世界哺乳动物排序第一的印度尼西亚(670种)。中国有150种特有哺乳动物,特有种比例为22.3%。兔形目特有种比例达43%,鼠兔科特有种比例更高达52%。劳亚食虫目的特有种比例为35%。中国灵长目、啮齿目和翼手目特有种比例约占各目总种数的1/5,翼手目特有种包括近十年发表、模式产地为中国的12个蝙蝠新种。《中国哺乳动物名录(2015)》为生物多样性研究与保护提供了最新的本底资料。     

Men's preferences for women's breast size and shape in four cultures

The morphology of human female breasts appears to be unique among primates due to their permanent fat deposits. It has been previously suggested that female breast morphology arose as a result of sexual selection. This is supported by evidence showing that women with larger breasts tend to have higher estrogen levels; breast size may therefore serve as an indicator of potential fertility. However, breasts become less firm with age and parity, and breast shape could thus also serve as a marker of residual fertility. Therefore, cross-culturally, males are hypothesized to prefer breast morphology that indicates both high potential and residual fertility. To test this, we performed a survey on men's preferences for breast morphology in four different cultures (Brazil, Cameroon, the Czech Republic, Namibia). As stimuli, we used two sets of images varying in breast size (marker of potential fertility) and level of breast firmness (marker of residual fertility). Individual preferences for breast size were variable, but the majority of raters preferred medium sized, followed by large sized breasts. In contrast, we found systematic directional preferences for firm breasts across all four samples. This pattern supports the idea that breast morphology may serve as a residual fertility indicator, but offers more limited support for the potential fertility indicator hypothesis. Future studies should focus on a potential interaction between the two parameters, breast size and firmness, which, taken together, may help to explain the relatively large variation in women's breast sizes.     

Men's revealed preference for their mates' ages

Both young and old men say that they are sexually attracted to young, fertile women, but older men tend to marry older women, including those who are peri- and post-menopausal. We assessed men's freely revealed preference for their mates' age using an unusual marriage phenomenon in South Korea: the practice in which men purchase their brides from developing countries. Presumably, the men's mate choice, at least regarding the brides' age, is unrestricted by women. We analyzed all first marriages reported in 2010–2014 in South Korea and compared men who married Korean brides (N = 1,088,457) with those who purchased their brides (N = 45,528); the age range of grooms and brides was 15–59. While the former exhibited the typical pattern where older men married older women, the latter, whether young or old, always married young, fertile women. This finding is consistent with men's stated preference for young, fertile women in mating and suggests that the typical pattern is generated by women's limiting role in mating.     

Climatic significance of isotope ratios

The hydrogen and oxygen isotope ratios of water, which can be measured by Isotope Ratio Mass Spectrometry (IRMS), exhibit climatic dependencies and are commonly exploited in hydrogeology. More generally, the overall carbon or hydrogen isotope ratios of plant organic matter, and in particular of tree-ring cellulose, have been frequently used for climatic reconstruction. However, since many physicochemical and biochemical fractionation phenomena are likely to contribute to the isotopic values, the interpretation of the climatic significance of isotopic parameters is not always straightforward. In the case of hydrogen and oxygen for instance, the climatic profile of the source meteoric water is not simply transferred to leaf water and many steps of the biosyntheses are accompanied by kinetic and thermodynamic isotope effects that depend on the individual mechanistic pathways. The information brought about by overall isotope ratios determined by IRMS is averaged over all fractionation effects undergone at the different molecular positions. In contrast, the NMR investigation of Site-specific Natural Isotope Fractionation (SNIF-NMR) gives simultaneous access to isotope ratios specific to individual positions in the molecule. Since the different atoms do not necessarily exhibit the same climatic dependency, the method provides complementary responses to the environmental conditions. In particular, the isotopic parameters of ethanol and water obtained by fermenting sugars in standardized conditions reflect climatic influences which took place at different periods of plant growth. As a consequence, statistical analyses based on multi-site isotopic variables provide powerful criteria for distinguishing geographical regions of cultivation characterized by different climatic features. Although the sensitivity to climatic variations is the most pronounced for plant water and for sugars formed at the first step of photosynthesis, other components such as lipids or minor metabolites also exhibit climatic dependencies. The combination of isotopic values pertaining to different atomic species and either averaged over the whole molecule (IRMS) or associated with different molecular sites (SNIF-NMR), provides complementary criteria, which can be exploited in terms of both climatic significance and mechanistic pathways of the individual atoms.