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Cercopithecines have a highly conserved social structure with strong female bonds and stable, maternally inherited linear dominance hierarchies. This system has been ascribed to the pervasiveness of female philopatry within the typical multi-male, multi-female social groups. We examined the relationship between female philopatry, dominance hierarchies, and reproduction in geladas (Theropithecus gelada), a species with an unusual multi-leveled society. During a 4-year field study on a wild population in the Simien Mountains National Park, Ethiopia, we observed 14 units across two bands of geladas that underwent a number of events, such as male takeovers and female deaths, which could potentially disrupt female relationships and unit structure. First, we corroborate earlier reports that gelada females are natally philopatric: we observed no interunit migrations, and the female mortality rate was comparable to that of philopatric baboons (suggesting all female disappearances were indeed deaths). Second, contrary to previous reports, data from this long-term study show that geladas exhibit the linear and stable dominance hierarchies typical of other Cercopithecines. Moreover, female ranks appear to be maternally inherited. Third, we found no evidence that alpha females aggressively target the lowest ranking individuals, nor did rank confer clear reproductive advantages to dominant females within our 4-year observation period. As such, geladas fit the allostatic load model [Goymann & Wingfield, Animal Behaviour 67:591-602, 2004]. Our study confirms the importance of female philopatry in the kin-based Cercopithecine dominance system. 相似文献
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David J. Pappano Eila K. Roberts Jacinta C. Beehner 《American journal of primatology》2010,72(11):934-941
Four experiments were conducted to test different aspects of a “field‐friendly” fecal hormone extraction method that utilizes methanol extraction in the field followed by storage on C18 solid‐phase extraction cartridges. Fecal samples were collected from geladas (Theropithecus gelada) housed at the Bronx Zoo, and the experiments were conducted in a laboratory setting to ensure maximum control. The experiments were designed to either simulate the conditions to which fecal samples are subjected during fieldwork or improve on an existing protocol. The experiments tested the relationship between fecal hormone metabolite preservation/recovery and: (1) the amount of time a sample is stored at ambient temperature; (2) the number of freeze/thaw cycles a sample undergoes; (3) the effectiveness of different extraction solutions; and (4) the effectiveness of different cartridge washes. For each experiment, samples were assayed by radioimmunoassay for fecal glucocorticoid (GC) and testosterone (T) metabolites. Results for each of the experiments were as follows. First, storage at ambient temperature did not affect hormone levels until 4 weeks of storage, with significant increases for both GC and T metabolites at 4 weeks. Second, hormone levels significantly decreased in samples after two freeze/thaw cycles for GCs and six freeze/thaws cycles for T. Third, for both GCs and T, hormone extraction using various methanol solutions was significantly higher than using 100% ethanol. Finally, using a 20% methanol solution to wash cartridges significantly increased GC levels but had no effect on T levels. These results suggest that, when utilizing C18 cartridges for fecal steroid storage, researchers should consider several methodological options to optimize hormone preservation and recovery from fecal samples. Am. J. Primatol. 72:934–941, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
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N Snyder-Mackler SC Alberts TJ Bergman 《Proceedings. Biological sciences / The Royal Society》2012,279(1743):3788-3795
By living in social groups with potential competitors, animals forgo monopolizing access to resources. Consequently, debate continues over how selection might favour sociality among competitors. For example, several models exist to account for the evolution of shared reproduction in groups. The 'concession model' hypothesizes that dominant reproducers benefit from the presence of subordinates, and hence tolerate some reproduction by subordinates. This mutual benefit to both dominants and subordinates may provide a foundation for the formation of social groups in which multiple members reproduce-a necessary step in the evolution of cooperation. To date, however, the concession model has received virtually no support in vertebrates. Instead, the vast majority of vertebrate data support 'limited control models', which posit that dominant reproducers are simply unable to prevent subordinates from reproducing. Here we present the most comprehensive evidence to date in support of the concession model in a vertebrate. We examined natural variation in the number of adult males in gelada (Theropithecus gelada) reproductive units to assess the extent of reproductive skew in multi-male units. Dominant ('leader') males in units that also had subordinate ('follower') males had a 30 per cent longer tenure than leaders in units that did not have followers, mainly because followers actively defended the group against potential immigrants. Follower males also obtained a small amount of reproduction in the unit, which may have functioned as a concession in return for defending the unit. These results suggest that dominants and subordinates may engage in mutually beneficial reproductive transactions, thus favouring male-male tolerance and cooperation. 相似文献
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Pierre M. Durand Richard E. Michod 《Evolution; international journal of organic evolution》2010,64(6):1533-1540
Molecular biology has entrenched the gene as the basic hereditary unit and genomes are often considered little more than collections of genes. However, new concepts and genomic data have emerged, which suggest that the genome has a unique place in the hierarchy of life. Despite this, a framework for the genome as a major evolutionary transition has not been fully developed. Instead, genome origin and evolution are frequently considered as a series of neutral or nonadaptive events. In this article, we argue for a Darwinian multilevel selection interpretation for the origin of the genome. We base our arguments on the multilevel selection theory of hypercycles of cooperative interacting genes and predictions that gene‐level trade‐offs in viability and reproduction can help drive evolutionary transitions. We consider genomic data involving mobile genetic elements as a test case of our view. A new concept of the genome as a discrete evolutionary unit emerges and the gene–genome juncture is positioned as a major evolutionary transition in individuality. This framework offers a fresh perspective on the origin of macromolecular life and sets the scene for a new, emerging line of inquiry—the evolutionary ecology of the genome. 相似文献
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Bing Lin Iris R. Foxfoot Carrie M. Miller Vivek V. Venkatamaran Jeffrey T. Kerby Emily K. Bechtold Bryce S. Kellogg Nga Nguyen Peter J. Fashing 《American journal of primatology》2020,82(2):e23098
Predation is widely believed to exert strong selective pressure on primate behavior and ecology but is difficult to study and rarely observed. In this study, we describe seven encounters between lone wild leopards (Panthera pardus) and herds of geladas (Theropithecus gelada) over a 6-year period in an intact Afroalpine grassland ecosystem at the Guassa Community Conservation Area, Ethiopia. Three encounters consisted of attempted predation on geladas by leopards, one of which was successful. All three attacks occurred in low-visibility microhabitats (dominated by tussock graminoids, mima mounds, or tall shrubs) that provided leopards with hidden viewsheds from which to ambush geladas. An additional four encounters did not result in an attempted attack but still document the consistently fearful responses of geladas to leopards. In encounters with leopards, geladas typically gave alarm calls (n = 7 of 7 encounters), reduced interindividual distances (n = 5), and collectively fled towards or remained at their sleeping cliffs (n = 7), the only significant refugia in the open-country habitat at Guassa. Geladas did not engage in mobbing behavior towards leopards. Encounters with leopards tended to occur on days when gelada herd sizes were small, raising the possibility that leopards, as ambush hunters, might stalk geladas on days when fewer eyes and ears make them less likely to be detected. We compare the behavioral responses of geladas to leopards at Guassa with those previously reported at Arsi and the Simien Mountains and discuss how gelada vulnerability and responses to leopards compare with those of other primate species living in habitats containing more refugia. Lastly, we briefly consider how living in multilevel societies may represent an adaptive response by geladas and other open-country primates to predation pressure from leopards and other large carnivores. 相似文献
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Fashing PJ Nguyen N Barry TS Goodale CB Burke RJ Jones SC Kerby JT Lee LM Nurmi NO Venkataraman VV 《American journal of primatology》2011,73(5):405-409
Despite intensive study in humans, responses to dying and death have been a neglected area of research in other social mammals, including nonhuman primates. Two recent reports [Anderson JR, Gillies A, Lock LC. 2010. Pan thanatology. Current Biology 20:R349–R351; Biro D, Humle T, Koops K, Souse C, Hayashi M, Matsuzawa T. 2010. Chimpanzee mothers at Bossou, Guinea carry the mummified remains of their dead infants. Current Biology 20:R351–R352] offered exciting new insights into behavior toward dying and dead conspecifics in our closest living relatives—chimpanzees. Here, we provide a comparative perspective on primate thanatology using observations from a more distant human relative—gelada monkeys (Theropithecus gelada)—and discuss how gelada reactions to dead and dying groupmates differ from those recently reported for chimpanzees. Over a 3.75‐year study period, we observed 14 female geladas at Guassa, Ethiopia carrying dead infants from 1 hr to ≥48 days after death. Dead infants were carried by their mothers, other females in their group, and even by females belonging to other groups. Like other primate populations in which extended (>10 days) infant carrying after death has been reported, geladas at Guassa experience an extreme climate for primates, creating conditions which may favor slower rates of decomposition of dead individuals. We also witnessed the events leading up to the deaths of two individuals and the responses by groupmates to these dying individuals. Our results suggest that while chimpanzee mothers are not unique among primates in carrying their dead infants for long periods, seemingly “compassionate” caretaking behavior toward dying groupmates may be unique to chimpanzees among nonhuman primates (though it remains unknown whether such “compassionate” behavior occurs outside captivity). Am. J. Primatol. 73:405–409, 2011. © 2010 Wiley‐Liss, Inc. 相似文献
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Ana Garoa Nils F Hülter Devani Romero Picazo Tal Dagan 《Molecular biology and evolution》2021,38(12):5610
Plasmids are extrachromosomal genetic elements in prokaryotes that have been recognized as important drivers of microbial ecology and evolution. Plasmids are found in multiple copies inside their host cell where independent emergence of mutations may lead to intracellular genetic heterogeneity. The intracellular plasmid diversity is thus subject to changes upon cell division. However, the effect of plasmid segregation on plasmid evolution remains understudied. Here, we show that genetic drift during cell division—segregational drift—leads to the rapid extinction of novel plasmid alleles. We established a novel experimental approach to control plasmid allele frequency at the levels of a single cell and the whole population. Following the dynamics of plasmid alleles in an evolution experiment, we find that the mode of plasmid inheritance—random or clustered—is an important determinant of plasmid allele dynamics. Phylogenetic reconstruction of our model plasmid in clinical isolates furthermore reveals a slow evolutionary rate of plasmid-encoded genes in comparison to chromosomal genes. Our study provides empirical evidence that genetic drift in plasmid evolution occurs at multiple levels: the host cell and the population of hosts. Segregational drift has implications for the evolutionary rate heterogeneity of extrachromosomal genetic elements. 相似文献
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Alex Garcia‐Cisneros Creu Palacín Carlos Renato Rezende Ventura Barbara Feital Paulo Cesar Paiva Rocío Pérez‐Portela 《Molecular ecology》2018,27(3):752-772
Intraspecific genetic diversity and divergence have a large influence on the adaption and evolutionary potential of species. The widely distributed starfish, Coscinasterias tenuispina, combines sexual reproduction with asexual reproduction via fission. Here we analyse the phylogeography of this starfish to reveal historical and contemporary processes driving its intraspecific genetic divergence. We further consider whether asexual reproduction is the most important method of propagation throughout the distribution range of this species. Our study included 326 individuals from 16 populations, covering most of the species’ distribution range. A total of 12 nuclear microsatellite loci and sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene were analysed. COI and microsatellites were clustered in two isolated lineages: one found along the southwestern Atlantic and the other along the northeastern Atlantic and Mediterranean Sea. This suggests the existence of two different evolutionary units. Marine barriers along the European coast would be responsible for population clustering: the Almeria–Oran Front that limits the entrance of migrants from the Atlantic to the Mediterranean, and the Siculo‐Tunisian strait that divides the two Mediterranean basins. The presence of identical genotypes was detected in all populations, although two monoclonal populations were found in two sites where annual mean temperatures and minimum values were the lowest. Our results based on microsatellite loci showed that intrapopulation genetic diversity was significantly affected by clonality whereas it had lower effect for the global phylogeography of the species, although still some impact on populations’ genetic divergence could be observed between some populations. 相似文献
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Hindgut fermentation has been suggested to contribute significantly to the digestive process in the gelada (Theropithecus gelada). We therefore hypothesized that in an in vitro fermentation test (Hohenheim gas test, using gas production as measure of microbial digestion) inoculum based on fresh gelada feces would degrade grass to a similar degree as zebra (Equus burchelli chapmani) feces and to a higher degree than that of hamadryas baboons (Papio hamadryas). Additionally, morphology of gelada tongue, salivary glands, stomach, and intestine were examined in this study. Gas production was measured between 4 and 96 hr using animal feces incubated with 200 mg of air-dry hay or mixed concentrate sample. For grass hay, 12-hr gas production was as follows: T. gelada (19.9 ml)>Papio (18.4 ml)>Equus (15.7 ml). After 24 hr, gas production changed: Papio (35.1 ml)>T. gelada (31.9 ml)>Equus (27.9 ml). At 96 hr, Papio was unexpectedly the most effective species with the highest gas production (53.1 ml)>zebra (51.2 ml)>gelada (49.4 ml). With a concentrate standard, 12-hr gas production was as follows: T. gelada (38.5 ml)>Equus (36.8 ml) = Papio (36.4 ml). At 24 hr, gas production differed: Papio (51.7 ml)>Equus (47.0 ml) = T. gelada (46.8 ml). At 96 hr, zebra was the most effective species with the highest gas production (63.9 ml)>Papio (60 ml) = T. gelada (59.9 ml). In conclusion, the results show that the microbial population present in gelada feces is able to ferment forage and concentrate substrates in vitro, although this fermentation did not occur with the expected effectiveness. Future studies should therefore focus also on the bacteria species involved. 相似文献
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Biomaterials such as bone,teeth,nacre and silk are known to have superior mechanical properties due to their specificnanocomposite structures.Here we report that the woodpecker’s tongue exhibits a novel strength and flexibility due to its specialcomposite micro/nanostructure.The tongue consists of a flexible cartilage-and-bone skeleton covered with a thin layer tissue ofhigh strength and elasticity.At the interface between the cartilage-and-bone skeleton and the tissue layer,there is a hierarchicalfiber-typed connection.It is this special design of the tongue that makes the woodpeckers efficient in catching the insects insidetrees.The special micro/nanostructures of the woodpecker’s tongue show us a potential method to enhance the interfacialconnection between soft and hard material layers for bio-inspired composite system designs. 相似文献
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Until relatively recently many species of entomostracan crustaceans were thought to have widespread, even cosmopolitan distributions. Evidence now suggests that this is far less the case than thought. However, an exception appears to be provided by the crustaceans of episodically filled waterbodies. Typically these include Anostraca, Notostraca and Conchostraca. The paper considers the distribution of Triops australiensis (Branchiopoda: Notostraca) in Australia. There, it is a frequent inhabitant of episodically filled temporary waters. It is absent from such waters in northern Australia. A biogeoclimatic analysis using the program BIOCLIM indicates that this is because of the absence of suitable localities. BIOCLIM enables the preparation of maps which provide statistical predictions of climates suitable for the survival of a particular taxon. These predictions are based upon the known climate of localities where the taxon in question actually occurs. It is suggested that for the biota of shallow ephemeral waters (such as those typically inhabited by Anostraca, Conchostraca and Notostraca) biogeoclimatic analysis has a powerful predictive value. 相似文献
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Franziska Trede Anna Lemkul Anagaw Atickem Jacinta C. Beehner Thore J. Bergman Ryan Burke Peter J. Fashing Sascha Knauf Addisu Mekonnen Amera Moges Nga Nguyen Christian Roos Dietmar Zinner 《Zoologica scripta》2020,49(6):659-667
The subspecific taxonomy and distribution of geladas (Theropithecus gelada Rüppell, 1835) remains uncertain. Recent molecular studies based on mitochondrial sequence data revealed a geographically structured, three-deme population, suggesting that there are three evolutionary units of geladas. However, mitochondrial distributions do not always recover population relationships, particularly in taxa with a complex history of isolation and gene flow. We therefore analysed the nuclear genetic population structure of the global gelada population based on 20 microsatellite loci in 43 samples from across its geographic range. FST values, a STRUCTURE analysis and a principal coordinate analysis (PCoA) confirmed the three-deme population structure corresponding to the mitochondrial population structure. Therefore, our analyses provide additional support for three evolutionary units in geladas, corresponding to (a) a northern (north of Lake Tana, primarily in the Simien Mountains, previously classified as Theropithecus gelada gelada Rüppell, 1835), (b) a central (between Addis Ababa and the highlands east of Lake Tana, previously classified as Theropithecus gelada obscurus Heuglin, 1863) and (c) a southern (south of the Rift Valley, previously tentatively classified as Theropithecus gelada arsi Shotake et al., 2016, Anthropological Science, 124, 157) population. These results pave the way for future conservation decisions and highlight that the gelada population boundaries need more fine-grained genetic sampling and phenotypic analyses, in particular for their taxonomic ranking. 相似文献
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Dennis D. Kunkel 《Protoplasma》1984,123(2):104-115
Summary An ultrastructural examination of cell division in two baeocyte producing cyanobacteria,Pleurocapsa minor andDermocarpa violaceae, reveals two distinct patterns of binary (transverse) fission. Septate binary fission, inPleurocapsa minor, involves centripetal synthesis and deposition of the mucopolymer cell wall layer (L 2). The ingrowth of the cytoplasmic membrane and L 1 cell wall layer, along with the synthesis of the L 2 cell wall layer, results in the formation of a prominent septum. Partitioning of the cell occurs by the constriction of the outer cell wall layers (L 3 and L 4) through the septum. InDermocarpa violaceae, constrictive binary fission occurs by the simultaneous ingrowth or constriction of the cytoplasmic membrane and all cell wall layers (L1, L2, L3, L4). Septate and constrictive binary fission may proceed symmetrically (medially) or asymmetrically (nonmedially). Multiple fission occurs regularly inDermocarpa violaceae and provides for a rapid means of reproduction when compared to binary fission. Successive radial and tangential divisions of the protoplast result in formation of many small daughter cells (baeocytes). The process of multiple fission is similar to septate binary fission with reduced septa being formed. However, constriction of the outer cell wall layers, through the septa, proceeds concurrently with septum formation. 相似文献
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Hugo Loning;Rita Fragueira;Marc Naguib;Simon C. Griffith; 《Journal of avian biology》2023,2023(11-12):e03140
The social and spatial organisation of avian societies is often complex and dynamic with individuals socialising with others in a local population. Although social interactions can readily be described in colonial breeders through the location of nests, social interactions regularly take place in other contexts that are often not considered. Social behaviour in the colonially breeding zebra finch, Taeniopygia guttata, has been the focus of much work in the laboratory, but very little is known about their social organisation in free-living populations, especially outside the breeding context. Here we characterise semi-permanent gathering locations, or ‘social hotspots' in the zebra finch in the wild. We determined the use of such social hotspots and the resulting group dynamics by quantifying movements to and from these locations through direct observation and by quantifying the vocal activity at these locations using acoustic recorders. We show that, throughout the day, zebra finches regularly visit these hotspots, and the hotspots are occupied for a substantial proportion of the day. Individuals typically arrived and left in pairs, or small groups, indicating that these social hotspots do not function just for flock formation. Instead, the high levels of vocal activity at these hotspots indicate that they may potentially function as local hubs for socialisation and information exchange, whilst also perhaps providing safety-in-numbers benefits to individuals during periods of resting. These findings characterise an important component of the natural social life of one of the most widely studied birds in captivity. The characterisation of these social hotspots highlights the use of landmarks by birds to facilitate social contacts, cohesion, and behaviour, in a social bird. Similar hangouts and social hotspots may be a feature of social behaviour in other multi-level aggregative species in which the fission and fusion of groups is an important component of daily life. 相似文献
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