Phylogeny and biogeography of Aralia sect. Aralia (Araliaceae)

Aralia sect. Aralia (Araliaceae) consists of approximately eight species disjunctly distributed in Asia and North America. Phylogenetic and biogeographic analyses were conducted using sequences of the internal transcribed spacer regions of the nuclear ribosomal DNA. Aralia racemosa from eastern North America was sister to A. californica from western North America. Aralia cordata from eastern Asia did not form a species-pair relationship with the eastern North American A. racemosa. The two subspecies of A. racemosa formed a monophyletic group. Biogeographic analyses showed a close area relationship between eastern North America and western North America. The Himalayas were cladistically basal and eastern Asia was placed between the Himalayas and North America. The biogeographic analysis supported the origin of the eastern Asian and eastern North American disjunct pattern in Aralia sect. Aralia via the Bering land bridges. Comparisons with results of phylogenetic analyses of other genera suggested that (1) the floristic connection between eastern North America and western North America may be stronger than previously thought; and (2) the biogeographic patterns in the Northern Hemisphere are complex. Furthermore, a lack of correlation between sequence divergence values and phylogenetic positions was observed, suggesting the importance of a phylogenetic framework in biogeographic analyses.     

Reconstructing the genetic admixture history of Tai-Kadai and Sinitic people: Insights from genome-wide SNP data from South China

South China (SC) was a region with mixed rice–millet farming during the Middle Neolithic period and was also suggested to be the homeland of Tai-Kadai (TK)-speaking people. However, the formations of inland TK-speaking people and southwestern Hans are far from clear due to very few studies on this subject. Here, we reveal the spatiotemporally demographic history of SC by analyzing newly-generated genome-wide SNP data of 115 modern southwestern individuals and find that inland TK-speaking Dongs and Bouyeis have a close genomic affinity to coastal TK/Austronesian (AN)-speaking people and Neolithic Yangtze River basin (YZRB) farmers, while southwestern Hans and TK-speaking Gelaos possess a close genomic affinity to Neolithic Yellow River basin (YRB) farmers. Genetic differentiations are identified among TK people from SC and Southeast Asia, and between northern and southern inland Chinese TK people, in which the identified shared genetic ancestry between TK and AN people highlights a common origin of AN/TK groups. Conclusively, our findings indicate that millet farmers deriving from the YRB and rice farmers deriving from the YZRB substantially contribute to the present-day inland TK speakers and southwestern Hans via a two-way admixture scenario of bi-directional gene-flow events, which facilitates the formation of a modern two-way genetic admixture profile.     

亚洲象与竹/蕉分布隔离的生态效果及其保护对策探讨

把分布在滇南的西双版纳自然保护区内的亚洲象频繁出走 ,毁坏农作物、伤害人畜的原因与自然保护区片断化以及它们与其重要采食植物黄竹、野芭蕉等分布的隔离联系起来探讨 ,由此提出了对亚洲象保护的一些措施。由于亚洲象在西双版纳几乎没有天敌 ,而且也得到较好的保护 ,其群居自 1 976年以来 ,由 1 0 1头发展至约 2 5 0头 ,自然保护区片断化和食物匮缺成为亚洲象走出自然保护区的重要原因。相反 ,在没有亚洲象控制的地区 ,黄竹和野芭蕉等以其高效的繁殖能力以及耐火烧的特性而在一些刀耕火种的弃荒地和退化生态系统迅速发展 ,成为以它们各自为优势的群落 (丛 ) ,大幅度地降低了群落的物种多样性     

Weaning Age,Infant Care,and Behavioral Development in <Emphasis Type="Italic">Trachypithecus leucocephalus</Emphasis>

Primate infants are born in an altricial state and rely on the care of their parents for a relatively long period of time. Parental investment is critical to offspring survival and thus to the reproductive success of the parent as well. However, mothers and infants may experience a conflict of interest, in that infants may benefit by receiving prolonged maternal care but mothers may curtail such care in a tradeoff between investment in current versus future offspring. Documenting life history characteristics, such as age at weaning, is important not only for understanding the conflicts of interest and tradeoffs; such information can also provide insights about female reproductive rates and be valuable for conservation efforts. Little is known about the life history of white-headed langurs (Trachypithecus leucocephalus), despite their endangered status. We were the first to investigate mother-infant relationships and infant behavioral development in the species. We studied 3 wild mother-infant pairs throughout infancy. We used data from >460 h of focal subject sampling to calculate the proportion of time individuals spent in different behavioral states and the frequency of instantaneous events, such as maternal rejection. White-headed langur infants depended on their mothers for 19–21 mo, at which time they were weaned. Maternal rejection facilitated infant independence in the early stages of infant development, and mothers stopped investing in their infants when they resumed estrus. The weaning age of the wild white-headed langurs we studied was dramatically longer than that of captives, possibly as a result of the nutritional differences between wild and captive populations. Weaning age was also longer than for most other Asian colobines, and may be attributable to the degradation and fragmentation of their natural habitat.     

It’s Tough Out There: Variation in the Toughness of Ingested Leaves and Feeding Behavior Among Four Colobinae in Vietnam

Colobines are similar in their exploitation of a high percentage of leaf matter. However, this observation obfuscates interesting differences among genera of Southeast Asian colobines in morphology and behavior that may be reflected in the degree to which they rely on mastication or gut volume and gut retention time when ingesting and digesting leaves. We detail the use of a laboratory-based method to measure the mechanical properties of foods selected and processed by 4 captive species of Southeast Asian Colobinae —Pygathrix nemaeus, Pygathrix cinerea, Trachypithecus delacouri, and Trachypithecus laotum hatinhensis— at the Endangered Primate Rescue Center (EPRC), Vietnam. We also detail a field method that quantifies chewing rates and chewing behavior via a consumer-grade video camera and laptop computer. Observations in the captive setting permit a degree of experimental control that is not possible in the wild, and the location of the EPRC in the primates’ habitat country permitted us to provide leaves that they encounter and eat in the wild. We collected toughness data with a portable tester designed by Lucas et al. The average toughness of selected leaves does not differ among the taxa, nor does the length of time spent chewing foods. However, there are differences in feeding rate, with Trachypithecus spp. chewing foods twice as fast as Pygathrix spp. Our findings suggest that Trachypithecus spp. emphasize comminution of food by mastication, while Pygathrix spp. emphasize the comminution of leaf matter in the stomach. The hypothesis is supported by data on molar size, gut mass, and gut morphology. We provide new insights into dietary variation among primate species and detail methods that are typically conducted only in a laboratory setting. We augment the findings with additional data on activity, feeding rates, and tooth morphology.     

Behavioral evidence for a female-produced sex attractant in Diaphorina citri

Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is an important worldwide pest of citrus. It vectors three phloem-restricted bacteria in the genus Candidatus Liberibacter that cause huanglongbing (citrus greening disease). Studies were conducted to examine the behavioral responses of male and female D. citri to conspecifics of the same and opposite sex, with and without associated citrus host plants, in both open-air arena choice assays and Y-tube olfactometer assays. Virgin and mated male D. citri colonized citrus plants that were currently or had been previously colonized by virgin or mated female D. citri in greater numbers than control plants without females. However, males or females did not accumulate more on plants colonized by conspecifics of the same sex compared to uninfested plants, and females showed no preference for plants pre-infested with males compared with uninfested controls. In complementary Y-tube olfactometer assays, virgin and mated males chose arms with odor sources from mated females compared with blank controls in the absence of associated citrus host plant volatiles. In both behavioral assays, mated female D. citri appeared more attractive than virgin females. The vibrational calling behavior of male D. citri was reduced when males were challenged by the odors of conspecific mated females relative to when males were challenged by the odor of other males. Collectively, our results provide behavioral evidence for a female-produced volatile sex attractant pheromone in D. citri . Future identification and synthesis of a sex attractant pheromone will be an important contribution to current monitoring and management practices for D. citri .     

云南蒙古族体质特征

在云南省通海县调查了439例(男为202例, 女为237例)蒙古族人的67项体质指标(9项观察指标和58项测量指标), 计算出32项体质指数, 并对身高和11项指数进行了分型统计。研究结果表明: (1)云南蒙古族有蒙古褶率较低,有上眼睑皱褶率较低。鼻根高度男的中型率最高, 女的低型率最高。鼻翼高度男女均以中型率最高, 上唇皮肤部高度男女多为中等; 耳垂男女以三角形率最高。发色多为黑色, 眼色多为褐色, 肤色多为黄色。(2)云南蒙古族身高男女均为亚中等身材, 男性的亚中等型率最高, 女性的矮型率最高。按分型比例来看, 云南蒙古族男女均为中头型(头长宽指数)、高头型、超狭面型、中胸型、中肩型、中腿型、窄骨盆型、中躯干型率最高。头宽高指数男性为中头型率最高, 女性为阔头型率最高。(3)在7个蒙古族族群中, 蒙古族头长值、鼻高值最大, 鼻宽、口裂宽、形态面高值最大,头宽、额最小宽、面宽、身高、体重值最小。(4)在14个云南族群中, 云南蒙古族形态面高、鼻高、体重值大, 身高值较大,鼻宽、口裂宽值较小。(5)云南蒙古族体质与阿昌、白族、彝族最为接近。(6)云南蒙古族总体上属于蒙古人种南亚类型体质, 是南亚类型中体质相对接近于北亚类型的一个族群。(7)云南蒙古族体质形成与其族源及与周边族群的基因交流有关。     

Strengthening of the East Asian summer monsoon revealed by a shift in seasonal patterns in diet and climate after 2-3 Ma in northwest China

To examine climate variability in northwest China in the late Cenozoic and to test hypotheses regarding the development of C₄ ecosystems and the dynamics of the Asian monsoons, the carbon and oxygen isotopic compositions of 32 bulk and 368 serial tooth enamel samples from herbivores in the Linxia Basin (Gansu Province), ranging in age from 25 Ma to the present, were determined. The results corroborate and improve the record previously obtained from the area, showing that all mammals in the Linxia Basin lived in habitats consisting primarily of C₃ vegetation prior to 2-3 Ma and that C₄ grasses did not become a significant component of local ecosystems until the Quaternary. The data also show that shifts in climate to drier and/or warmer conditions after about 14, 9.5, 7, and 2.5 Ma, as indicated by positive δ¹⁸O excursions in the bulk enamel-δ¹⁸O record, were accompanied by increased seasonality; whereas negative δ¹⁸O shifts in the bulk data after about 11, 6, and 1.2 Ma, which indicate shifts to wetter and/or cooler climate, were associated with decreases in seasonality. Intra-tooth δ¹³C and δ¹⁸O profiles reveal significant changes in the seasonal patterns of diet and climate after ~ 2-3 Ma. Prior to ~ 2-3 Ma, there was little or no seasonal variation in herbivores' diets and all herbivores fed on C₃ vegetation year around. After that time, the data show a significant seasonal variation in the diets of horses and bovids, ranging from a pure C₃ to a mixed C₃/C₄ diet (with C₄ plants accounting for up to ~ 60% of the diet). An inverse relationship (or negative correlation) between δ¹³C and δ¹⁸O values within individual teeth — a pattern characteristic of the summer monsoon regime — is observed in younger (< 2-3 Ma) horses and bovids but not in older fossils. These changes in intra-tooth isotopic patterns provide strong evidence for an enhanced monsoon climate since about 2-3 Ma.     

东亚现代人的起源

古遗传学过去十年的发展表明, 现代人在全新物种——智人的出现过程中并没有一个系统发育学意义上的起源, 因此, 解剖学、行为学和遗传学方面的现代性并不是一个相同且单一事件的结果。本文研究了东亚解剖学、行为学和遗传学方面的证据,现代性在每个方面都可以被理解为多地区进化过程的一个片段, 而不是一个整体。三个方面的现代性在某种程度上是相互独立的, 而且各自都是在不同的时间发展出来, 直到晚更新世的人口变化才使三者相互关联起来; 人类存活率的提高和不断扩张改变了人类的进化行程。     

亚洲玉米螟对丁硫克百威的抗性筛选及交互抗性

采用点滴法测定丁硫克百威对亚洲玉米螟Ostrinia furnacalis(Guenée)幼虫的致死中量,并采用亚致死剂量筛选亚洲玉米螟10代。结果表明,丁硫克百威处理亚洲玉米螟5代后,抗性即显著上升,抗性倍数为3.23倍,到10代时,抗性达到了5.43倍。对高效氯氟氰菊酯、辛硫磷和丁硫克百威3种玉米螟抗性品系进行交互抗性测定,发现丁硫克百威与其它2种农药存在交互抗性。建议在害虫防治谨慎使用丁硫克百威。