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1.
This research deals with the History of the human peopling of Far East Asia during the Late Upper Pleistocene. It brings some new answers to the question of modern human migrations in the Far East. This study is based on morphometric analysis of 45 fossil crania. The results of the multivariate analyses, combined with the recognition of geographic patterns of variation, separate the fossils into three morphological classes. These three clusters enable us to propose a likely scenario for the human peopling of the Far East from about 67 000 years ago. To cite this article: F. Demeter et al., C. R. Palevol 2 (2003). 相似文献
2.
Late Pleistocene and Holocene population history of East Asia based on dental variation 总被引:5,自引:0,他引:5
C G Turner 《American journal of physical anthropology》1987,73(3):305-321
3.
Luísa Pereira Nuno M Silva Ricardo Franco-Duarte Verónica Fernandes Joana B Pereira Marta D Costa Haidé Martins Pedro Soares Doron M Behar Martin B Richards Vincent Macaulay 《BMC evolutionary biology》2010,10(1):1-10
Background
Altruistic anti-predatory behaviours pose an evolutionary problem because they are costly to the actor and beneficial to the recipients. Altruistic behaviours can evolve through indirect fitness benefits when directed toward kin. The altruistic nature of anti-predatory behaviours is often difficult to establish because the actor can obtain direct fitness benefits, or the behaviour could result from selfish coercion by others, especially in eusocial animals. Non-eusocial parthenogenetically reproducing aphids form colonies of clone-mates, which are ideal to test the altruistic nature of anti-predatory defence behaviours. Many aphids release cornicle secretions when attacked by natural enemies such as parasitoids. These secretions contain an alarm pheromone that alerts neighbours (clone-mates) of danger, thereby providing indirect fitness benefits to the actor. However, contact with cornicle secretions also hampers an attacker and could provide direct fitness to the actor.Results
We tested the hypothesis that cornicle secretions are altruistic by assessing direct and indirect fitness consequences of smearing cornicle secretions onto an attacker, and by manipulating the number of clone-mates that could benefit from the behaviour. We observed parasitoids, Aphidius rhopalosiphi, foraging singly in patches of the cereal aphid Sitobion avenae of varied patch size (2, 6, and 12 aphids). Aphids that smeared parasitoids did not benefit from a reduced probability of parasitism, or increase the parasitoids' handling time. Smeared parasitoids, however, spent proportionately more time grooming and less time foraging, which resulted in a decreased host-encounter and oviposition rate within the host patch. In addition, individual smearing rate increased with the number of clone-mates in the colony.Conclusions
Cornicle secretions of aphids were altruistic against parasitoids, as they provided no direct fitness benefits to secretion-releasing individuals, only indirect fitness benefits through neighbouring clone-mates. Moreover, the use of cornicle secretions was consistent with their altruistic nature, because the occurrence of this behaviour increased with the size of indirect fitness benefits, the number of clone-mates that can benefit. This study provides evidence for a case of kin-directed altruistic defence outside eusocial animals. 相似文献4.
Genetic consequences of Pleistocene range shifts: contrast between the Arctic, the Alps and the East African mountains 总被引:3,自引:2,他引:3
Ehrich D Gaudeul M Assefa A Koch MA Mummenhoff K Nemomissa S;Intrabiodiv Consortium Brochmann C 《Molecular ecology》2007,16(12):2542-2559
In wide-ranging species, the genetic consequences of range shifts in response to climate change during the Pleistocene can be predicted to differ among different parts of the distribution area. We used amplified fragment length polymorphism data to compare the genetic structure of Arabis alpina, a widespread arctic-alpine and afro-alpine plant, in three distinct parts of its range: the North Atlantic region, which was recolonized after the last ice age, the European Alps, where range shifts were probably primarily altitudinal, and the high mountains of East Africa, where the contemporary mountain top populations result from range contraction. Genetic structure was inferred using clustering analyses and estimates of genetic diversity within and between populations. There was virtually no diversity in the vast North Atlantic region, which was probably recolonized from a single refugial population, possibly located between the Alps and the northern ice sheets. In the European mountains, genetic diversity was high and distinct genetic groups had a patchy and sometimes disjunct distribution. In the African mountains, genetic diversity was high, clearly structured and partially in accordance with a previous chloroplast phylogeography. The fragmented structure in the European and African mountains indicated that A. alpina disperses little among established populations. Occasional long-distance dispersal events were, however, suggested in all regions. The lack of genetic diversity in the north may be explained by leading-edge colonization by this pioneer plant in glacier forelands, closely following the retracting glaciers. Overall, the genetic structure observed corresponded to the expectations based on the environmental history of the different regions. 相似文献
5.
Perceptual interferences in the estimation of quantities (time, space and numbers) have been interpreted as evidence for a common magnitude system. However, if duration estimation has appears sensitive to spatial and numerical interferences, space and number estimation tend to be resilient to temporal manipulations. These observations question the relative contribution of each quantity in the elaboration of a representation in a common mental metric. Here, we elaborated a task in which perceptual evidence accumulated over time for all tested quantities (space, time and number) in order to match the natural requirement for building a duration percept. For this, we used a bisection task. Experimental trials consisted of dynamic dots of different sizes appearing progressively on the screen. Participants were asked to judge the duration, the cumulative surface or the number of dots in the display while the two non-target dimensions varied independently. In a prospective experiment, participants were informed before the trial which dimension was the target; in a retrospective experiment, participants had to attend to all dimensions and were informed only after a given trial which dimension was the target. Surprisingly, we found that duration was resilient to spatial and numerical interferences whereas space and number estimation were affected by time. Specifically, and counter-intuitively, results revealed that longer durations lead to smaller number and space estimates whether participants knew before (prospectively) or after (retrospectively) a given trial which quantity they had to estimate. Altogether, our results support a magnitude system in which perceptual evidence for time, space and numbers integrate following Bayesian cue-combination rules. 相似文献
6.
Xiaowei Mao Hucai Zhang Shiyu Qiao Yichen Liu Fengqin Chang Ping Xie Ming Zhang Tianyi Wang Mian Li Peng Cao Ruowei Yang Feng Liu Qingyan Dai Xiaotian Feng Wanjing Ping Chuzhao Lei John W. Olsen E. Andrew Bennett Qiaomei Fu 《Cell》2021,184(12):3256-3266.e13
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Mixed mammal species groups are common in East African savannah ecosystems. Yet, it is largely unknown if co-occurrences of large mammals result from random processes or social preferences and if interspecific associations are consistent across ecosystems and seasons. Because species may exchange important information and services, understanding patterns and drivers of heterospecific interactions is crucial for advancing animal and community ecology. We recorded 5403 single and multi-species clusters in the Serengeti-Ngorongoro and Tarangire-Manyara ecosystems during dry and wet seasons and used social network analyses to detect patterns of species associations. We found statistically significant associations between multiple species and association patterns differed spatially and seasonally. Consistently, wildebeest and zebras preferred being associated with other species, whereas carnivores, African elephants, Maasai giraffes and Kirk''s dik-diks avoided being in mixed groups. During the dry season, we found that the betweenness (a measure of importance in the flow of information or disease) of species did not differ from a random expectation based on species abundance. In contrast, in the wet season, we found that these patterns were not simply explained by variations in abundances, suggesting that heterospecific associations were actively formed. These seasonal differences in observed patterns suggest that interspecific associations may be driven by resource overlap when resources are limited and by resource partitioning or anti-predator advantages when resources are abundant. We discuss potential mechanisms that could drive seasonal variation in the cost-benefit tradeoffs that underpin the formation of mixed-species groups. 相似文献
9.
Phylogenetic analysis identified haplochromine cichlids from isolated water bodies in the eastern branch of the East African Rift system as an ancient lineage separated from their western sister group in the course of the South Kenyan-North Tanzanian rift system formation. Within this lineage, the close phylogenetic relatedness among taxa indicates a recent common ancestry and historical connections between now separated water bodies. In connection with a total lack of local genetic diversity attributable to population bottlenecks, the data suggest cycles of extinction and colonization in the unstable habitat provided by the small lakes and rivers in this geologically highly active area. 相似文献
10.
Pérez-Pérez A Espurz V Bermúdez de Castro JM de Lumley MA Turbón D 《Journal of human evolution》2003,44(4):497-513
Non-occlusal, buccal tooth microwear variability has been studied in 68 fossil humans from Europe and the Near East. The microwear patterns observed suggest that a major shift in human dietary habits and food processing techniques might have taken place in the transition from the Middle to the Late Pleistocene populations. Differences in microwear density, average length, and orientation of striations indicate that Middle Pleistocene humans had more abrasive dietary habits than Late Pleistocene populations. Both dietary and cultural factors might be responsible for the differences observed. In addition, the Middle Paleolithic Neanderthal specimens studied show a highly heterogeneous pattern of microwear when compared to the other samples considered, which is inconsistent with a hypothesis of all Neanderthals having a strictly carnivorous diet. The high density of striations observed in the buccal surfaces of several Neanderthal teeth might be indicative of the inclusion of plant foods in their diet. The buccal microwear variability observed in the Neanderthals is compatible with an overall exploitation of both plant and meat foods on the basis of food availability. A preliminary analysis of the relationship between buccal microwear density and climatic conditions prevailing in Europe during the Late Pleistocene has been attempted. Cold climatic conditions, as indicated by oxygen isotope stage data, seem to be responsible for higher densities of microwear features, whereas warmer periods could correspond to a reduced pattern of scratch density. Such a relationship would be indicative of less abrasive dietary habits, perhaps more meat dependent, during warmer periods. 相似文献
11.
Carroll SA Reynes JM Khristova ML Andriamandimby SF Rollin PE Nichol ST 《Journal of virology》2011,85(13):6162-6167
Rift Valley fever virus (RVFV), a mosquito-borne phlebovirus, has been detected in Madagascar since 1979, with occasional outbreaks. In 2008 to 2009, a large RVFV outbreak was detected in Malagasy livestock and humans during two successive rainy seasons. To determine whether cases were due to enzootic maintenance of the virus within Madagascar or to importation from the East African mainland, nine RVFV whole genomic sequences were generated for viruses from the 1991 and 2008 Malagasy outbreaks. Bayesian coalescent analyses of available whole S, M, and L segment sequences were used to estimate the time to the most recent common ancestor for the RVFVs. The 1979 Madagascar isolate shared a common ancestor with strains on the mainland around 1972. The 1991 Madagascar isolates were in a clade distinct from that of the 1979 isolate and shared a common ancestor around 1987. Finally, the 2008 Madagascar viruses were embedded within a large clade of RVFVs from the 2006-2007 outbreak in East Africa and shared a common ancestor around 2003 to 2004. These results suggest that the most recent Madagascar outbreak was caused by a virus likely arriving in the country some time between 2003 and 2008 and that this outbreak may be an extension of the 2006-2007 East African outbreak. Clustering of the Malagasy sequences into subclades indicates that the viruses have continued to evolve during their short-term circulation within the country. These data are consistent with the notion that RVFV outbreaks in Madagascar result not from emergence from enzootic cycles within the country but from recurrent virus introductions from the East African mainland. 相似文献
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Joseph O. Ogutu Robin S. Reid Hans-Peter Piepho Nicholas T. Hobbs Michael E. Rainy Russell L. Kruska Jeffrey S. Worden Meshack Nyabenge 《Biodiversity and Conservation》2014,23(3):573-596
Water, forage and predation constrain ungulate distributions in savannas. To understand these constraints, we characterized distributions of 15 herbivore species from water, locations of peak density and degree of clustering around the peaks using zero-inflated count data models and mapping census data collected in the Mara reserve and the adjoining pastoral ranches in Kenya during a wet and dry year. Herbivores followed a humped pattern (n = 46), suggesting constrained foraging in which they balance the benefits of proximity to water with the costs of foraging where food is depleted near water and travelling to more abundant food distant from water; an exponentially decreasing pattern (n = 11), indicating strong attraction to water or vegetation near water; or a uniform (n = 3) pattern. The details rather than the types of these patterns varied between years. Herbivores concentrated farther from water and more tightly around locations of their peak densities in the ranches than the reserve. Herbivores were more abundant and widely distributed from water in the wet than the dry year, and segregated along the distance-to-water gradient, presumably to minimize interspecific competition for food. Pastoralism compressed herbivore distributions and partially excluded some species (warthog, hartebeest, topi, wildebeest, zebra, eland, buffalo and elephant) from, while attracting others (Grant’s and Thomson’s gazelles, impala, giraffe) to the ranches, relative to the reserve. Regulating cultivation, fencing, settlements and livestock stocking levels in the ranches would allow continued wildlife access to water, reduce competition with, displacement or harassment of wildlife by people, livestock and dogs near water. 相似文献
14.
The radiation of the East African cichlid fishes has engaged biologists for over a century. Because so much taxonomic diversity has evolved recently, they are an ideal natural system in which to study the process of speciation. Hypervariable microsatellite loci have been used to verify multiple paternity and maternity in cichlid broods, to quantify the fitness of cooperative breeders and reproductive parasites, to estimate effective population sizes in captive populations, and to illuminate the spatial and temporal scale of gene flow among natural populations. The patterns that have emerged from these studies often reflect important biological differences among taxa. The cichlid species of East Africa represent a large amount of taxonomic and adaptive diversity all neatly packaged into a single lineage and confined to a modest geographical area. Data from microsatellite loci are now providing us with the means to understand one of the world's most intriguing and instructive comparative evolutionary systems. 相似文献
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16.
C. Michael Barton Julien Riel-Salvatore John M. Anderies Gabriel Popescu 《Human ecology: an interdisciplinary journal》2011,39(6):705-725
Given the complex and multidimensional nature of human evolution, we need to develop theoretical and methodological frameworks
to account for and model the dynamic feedbacks between co-operational biological and cultural evolutionary systems to better
understand the processes that produced modern human behavior. Equally important is the generation of explicit theory-based
models that can be tested against the empirical paleoanthropological record. We present a case study that examines evidence
for culturally-driven behavioral change among Late Pleistocene hominins that altered the social niche occupied by hominins
in western Eurasia, with consequences for subsequent biological and cultural evolution. We draw on a large sample of 167 Pleistocene
assemblages across western Eurasia and employ mathematical and computational modeling to explore the feedbacks between cultural
and biological inheritance. Shifts in land-use strategies changed the opportunities for social and biological interaction
among Late Pleistocene hominins in western Eurasia with a cascade of consequences for cultural and biological evolution, including
the disappearance of Neanderthals from the fossil and archaeological records, and the acceleration of cultural evolution among
ancestors of modern humans. 相似文献
17.
Cross-sectional geometry and morphology of the mandibular symphysis in Middle and Late Pleistocene Homo 总被引:2,自引:0,他引:2
Studies of the evolutionary emergence of the human "chin" have been investigated from a phylogenetic perspective during the later Pleistocene or from a biomechanical perspective across extant primates. Since it was during the Middle and Late Pleistocene that the distinctive human mentum osseum emerged, the relationship between mentum osseum form and resistance to mechanical stress at the mandibular symphysis was examined for forty-two Middle and Late Pleistocene human mandibles. Mentum osseum variation was scored on a five-point ordinal scale (mentum osseum rank). Resistance to bending was represented by second moments of area calculated from symphyseal cross-sections. Relative strength in bending was represented by second moments of area divided by estimated moment arm or beam length. Vertical bending resistance in the coronal plane was maintained across the range of mentum osseum variation within and between later Pleistocene human groups. In contrast, resistance to lateral transverse bending (wishboning) was significantly negatively correlated with the emergence of a protruding mentum osseum. However, Neandertals and early modern humans were equivalent in their abilities to resist this bending regime, while both groups were less resistant in wishboning than earlier archaic humans. In addition, symphyseal inclination, which decreased throughout the later Pleistocene, was highly correlated with mentum osseum rank. Although the overall pattern of differential stasis and change in vertical bending and wishboning resistance at the symphysis is consistent with aspects of the current biomechanical model of the "chin," the decoupling of bending resistance and mentum osseum form in the Late Pleistocene suggests that the evolutionary emergence of the modern human "chin" was at least partly independent of the biomechanical demands placed on the symphysis. 相似文献
18.
This contribution reviews the worldwide record of canid and canid-like (creodont and hyaenid) fossil footprints, the taxonomy of this type of footprints, and reports a new record of canid footprints from the late Pleistocene Pehuen Co site of southern Buenos Aires province, Argentina. On the basis of the comparison of proposed ichnogenera and features of modern canid and felid footprints, a set of ichnogeneric and ichnospecific taxobases are proposed. The ichnotaxonomic review includes Bestiopeda Vialov, 1965; Canipeda Panin and Avram, 1962; Felipeda Panin and Avram, 1962; Pehuencoichnum Aramayo and Manera de Bianco, 1987b; Creodontipus Santamaría et al. 1989–1990; Tetrastoibopus Sarjeant and Langston, 1994; and Quiritipes Sarjeant et al. 2002. A key to discriminate these ichnotaxa is also proposed and the diagnosis of Canipeda emended. The new findings of canid footprints from Pehuen Co are indistinguishable from Pehuencoichnum gracilis Aramayo and Manera de Bianco, 1987b, and this ichnospecies is synonymized under Canipeda gracilis (Vialov, 1965). An emended diagnosis for C. gracilis is proposed. The most likely producer of C. gracilis from Pehuen Co is a medium-sized fox similar to the extant representatives of Lycalopex. 相似文献
19.
《Ostrich》2013,84(1-2):57-65
The Lesser Flamingo (Phoeniconaias minor) is thought to be highly nomadic. In East Africa, the number of individuals on a given lake has been shown to double or halve in a period of just two weeks. In general, interlake movements are believed to take place mostly at night. However, movement timing and patterns for individual birds are unknown. Between 12 and 23 October 2002, we affixed two solar-powered and two battery-powered satellite transmitters (PTTs) to four large (>2kg) adult male Lesser Flamingos at Lake Bogoria, Kenya. During the first three months, the four birds exhibited markedly different movement patterns. One moved 687km, making seven visits to four different lakes (mean stay: 11.4d). Another made five visits to only three different lakes (mean stay: 18.5 days), travelling only 263km. On two occasions, it remained on one lake for long periods (34 days and 70 days). A third moved among lakes in Kenya and Tanzania 44 times, visiting nine different lakes, spending an average of only 2.3 days at each and travelling a total of 4 792km in the process. The fourth is believed to have been predated on Lake Bogoria at the end of the first month. During the last six months of the study, the most active bird settled down and the behaviour of the three remaining birds was much more similar. They each spent long periods of time (e.g. 45-137d) at just one or two sites. During the study period, one bird made several short (21-81km) interlake flights during daylight hours. Flight speed was estimated to be approximately 68km h-1 during the only flight when speed could be calculated. Both solar-powered PTTs functioned well; light reaching the solar panels was not impaired by feathers or dried mineral crystals, both initial concerns. The solar-powered PTT with a pre-set 'on/off' duty cycle performed much better than the other with no pre-set duty cycle, indicating that small solar-powered units need substantial 'off' time to recharge their batteries, even in areas with 12h of sunlight daily. The key site network for Lesser Flamingos in East Africa consists of seven alkaline lakes in Kenya and Tanzania (Logipi, Bogoria, Nakuru, Elmenteita, Natron, Manyara and Eyasi) and an ephemeral fresh water wetland in central Tanzania (Bahi Swamp). The conservation status of these eight sites varies from well-protected (lakes Bogoria, Nakuru and Manyara) to completely unprotected (Logipi, Natron, Eyasi and Bahi Swamp), with Elmenteita being partially protected. 相似文献
20.
FAYSAL BIBI 《Zoological Journal of the Linnean Society》2011,162(3):699-711
Fossil Bovidae constitute one of the most significant proxy records for evolutionary and palaeoecological change in Africa. Tragelaphus nakuae is a regularly encountered antelope in the East African Plio‐Pleistocene, and is a common component of hominin faunas. As previously understood, this species ranged for almost 2 million years, encompassed a large range of morphological variation, exhibited relative stasis in the face of environmental perturbations, and left no known living descendants. I here review and revise the fossil record of this tragelaphin bovid, finding that specimens older than ~2.8 Mya and previously attributed to T. nakuae or a close form are in fact referable to a distinct, but ancestral, species. This new interpretation adds these fossil tragelaphins to the body of evidence supporting major faunal turnover occurring around 2.8 Mya in concert with global climatic change. I also document morphological changes that occur through the duration of T. nakuae, particularly after 2.3 Mya. These taxonomic revisions allow for refined biochronological estimates for several East African Plio‐Pleistocene sites and specimen assemblages of uncertain age. A phylogenetic analysis suggests that the T. nakuae lineage is related to the extant bongo (Tragelaphus eurycerus), relating this living but enigmatic forest antelope to the fossil record. One resulting palaeoecological hypothesis is that the bongo's modern fragmented range represents the relicts of a much more widely distributed late Pliocene African forest belt. This study highlights the importance of specimen‐based approaches for elucidating the pattern and timing of major evolutionary events. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 699–711. 相似文献