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Hollox EJ Poulter M Zvarik M Ferak V Krause A Jenkins T Saha N Kozlov AI Swallow DM 《American journal of human genetics》2001,68(1):160-172
Lactase persistence, the genetic trait in which intestinal lactase activity persists at childhood levels into adulthood, varies in frequency in different human populations, being most frequent in northern Europeans and certain African and Arabian nomadic tribes, who have a history of drinking fresh milk. Selection is likely to have played an important role in establishing these different frequencies since the development of agricultural pastoralism approximately 9,000 years ago. We have previously shown that the element responsible for the lactase persistence/nonpersistence polymorphism in humans is cis-acting to the lactase gene and that lactase persistence is associated, in Europeans, with the most common 70-kb lactase haplotype, A. We report here a study of the 11-site haplotype in 1,338 chromosomes from 11 populations that differ in lactase persistence frequency. Our data show that haplotype diversity was generated both by point mutations and recombinations. The four globally common haplotypes (A, B, C, and U) are not closely related and have different distributions; the A haplotype is at high frequencies only in northern Europeans, where lactase persistence is common; and the U haplotype is virtually absent from Indo-European populations. Much more diversity is seen in sub-Saharan Africans than in non-Africans, consistent with an "Out of Africa" model for peopling of the Old World. Analysis of recent recombinant haplotypes by allele-specific PCR, along with deduction of the root haplotype from chimpanzee sequence, allowed construction of a haplotype network that assisted in evaluation of the relative roles of drift and selection in establishing the haplotype frequencies in the different populations. We suggest that genetic drift was important in shaping the general pattern of non-African haplotype diversity, with recent directional selection in northern Europeans for the haplotype associated with lactase persistence. 相似文献
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The jaw, suprahyoid, and extrinsic tongue muscles were studied in 11 genera, belonging to five tribes, of Old World squirrels. Significant variation in most of the adductor muscles is evident. The most primitive state of sciuromorphy is seen in the African tree squirrels Paraxerus and Funisciurus, especially as reflected in the anterior deep masseter. A derived state of sciuromorphy is found in five genera of Old World squirrels and perhaps evolved independently in each. Reduction of the temporalis muscle was observed in three genera, distantly related to one another. A unique arrangement of the superficial masseter is reported in the Asian giant tree squirrels, Ratufa. The arrangement of the masseter in the African pygmy squirrel, Myosciurus, is very similar to that of the South American pygmy squirrel, Sciurillus. We present hypotheses about the functional significance of these differences. In the derived state of sciuromorphy, which is found in three cases in squirrels that feed extensively on hard fruits, the anterior deep masseter is well positioned to increase the strength of the power stroke of the incisor bite. Among the pygmy squirrels, the position of the anterior deep masseter suggests that it plays a more significant role in molar chewing. © 1996 Wiley-Liss, Inc. 1 This article is a US Government work and, as such, is in the public domain in the United States of America. 相似文献
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Todd R. Disotell 《Evolutionary anthropology》1996,5(1):18-24
The living Old World monkeys, family Cercopithecidae, are the most successful group of nonhuman primates alive today. Overall, they account for over one quarter of the extant genera of primates and approximately 40% of the species. They have an extensive fossil record extending back to the early and middle Miocene of Africa.1,2 Despite this specific diversity and a long evolutionary history, it is commonly argued that the group is relatively uniform in both its skeletal3 and dental4 anatomy, suggesting that much of the current taxonomic diversity is a relatively recent phenomenon. In such a species group, it is perhaps not surprising that the taxonomy of Old World monkeys is subject to many differing classifications. Thus, in recent years, authors have recognized as few as 10 and as many as 22 different genera within the family. Although some of this greater-than-two-fold difference in the number of genera can be attributed to the “splitting” versus “lumping” philosophies of different researchers, much of it is based on major disagreements over phylogenetic relationships. Recent studies of the genetics and chromosomes of this group have illuminated Old World monkey phylogeny in many ways. Some of these studies have resolved longstanding debates based on morphological data; others have revealed phylogenetic relationships that morphologists had never suspected. 相似文献
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This is a catalogue and discussion of the known dactylogyridean monogenean genera of siluriform fishes of the Old World. Of a total of 38 nominal genera, only 19 are considered valid. Seventeen of these 19 genera are currently in the Ancyrocephalidae (containing the Ancyrocephalinae and Ancylodiscoidinae), whilst the other two (Neocalceostoma and Neocalceostomoides) are in the Neocalceostomatidae. The 17 genera are Anchylodiscus, Ancylodiscoides, Bagrobdella, Bifurcohaptor, Bychowskyella, Chauhanellus, Cornudiscoides, Hamatopeduncularia, Mizelleus, Paraquadriacanthus, Pseudancylodiscoides, Protoancylodiscoides, Quadriacanthus, Schilbetrema, Schilbetrematoides, Synodontella and Thaparocleidus. Clariotrema Long, 1981 and Neobychowskyella Ma, Wang & Li, 1983 are considered synonyms of Bychowskyella Akhmerov, 1952, Anacornuatus Dubey, Gupta & Agarwal, 1992 is considered a synonym of Quadriacanthus Paperna, 1961, Mizellebychowskia Gupta & Sachdeva, 1990 is considered a synonym of Neocalceostoma Tripathi, 1959 and Hargitrema Tripathi, 1959 is treated as a synonym of Hamatopeduncularia Yamaguti, 1953. It is proposed that the Ancylodiscoidinae be raised to family status within the order Dactylogyridea to accommodate these 17 `ancyrocephalid' genera from siluriforms, together with Malayanodiscoides and Notopterodiscoides from notopterids. A key and the diagnostic characteristics of the 19 recognised dactylogyridean genera from catfishes plus two from notopterids, together with a list of species and synonyms, are included. New combinations made in this work are Thaparocleidus avicularia (Chen, 1987) n. comb., T. calyciflorus (Chen, 1987) n. comb., T. choanovagina (Luo & Lang, 1981) n. comb., T. dissimilis (Chen, 1988) n. comb., T. leiocassis (Reichenbach-Klinke, 1959) n. comb., T. meticulosa (Chen, 1987) n. comb., T. parasoti (Zhao & Ma, 1999) n. comb., T. persculpus (Chen, 1987) n. comb., T. valga (Chen, 1987) n. comb. and T. wulingensis (Yao & Wang, 1997) n. comb. [all from Silurodiscoides] and Bychowskyella glyptothoraci (Ma, Wang & Li, 1983) n. comb. [from Neobychowskyella]. 相似文献
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Wayne L Gray 《Comparative medicine》2008,58(1):22-30
Simian varicella virus (SVV) causes a natural erythematous disease in Old World monkeys and is responsible for simian varicella epizootics that occur sporadically in facilities housing nonhuman primates. This review summarizes the biology of SVV and simian varicella as a veterinary disease of nonhuman primates. SVV is closely related to varicella–zoster virus, the causative agent of human varicella and herpes zoster. Clinical signs of simian varicella include fever, vesicular skin rash, and hepatitis. Simian varicella may range from a mild infection to a severe and life-threatening disease, and epizootics may have high morbidity and mortality rates. SVV establishes a lifelong latent infection in neural ganglia of animals in which the primary disease resolves, and the virus may reactivate later in life to cause a secondary disease corresponding to herpes zoster. Prompt diagnosis is important for control and prevention of epizootics. Antiviral treatment for simian varicella may be effective if administered early in the course of infection.Abbreviations: FEAU, 1-(2′-deoxy-2′-flouro-β-D-arabinofuranosyl)-5-iodouracil, IE, immediate early, ORF, open reading frame, PBL, peripheral blood lymphocyte, SVV, simian varicella virus, VZV, varicella–zoster virusSimian varicella is a natural erythematous disease of Old World primates (Superfamily Cercopithecoidea, Subfamily Cercopithecinae), involving particularly patas (Erythrocebus patas), African green or vervet (Chlorocebus aethiops), and various species of macaque (Macaca spp.) monkeys. Epizootics of simian varicella occur sporadically in facilities housing nonhuman primates. These outbreaks are sometimes associated with high morbidity and mortality and the loss of valuable research animals. Simian varicella virus (SVV; Cercopithecine herpesvirus 9), a primate herpesvirus, is the etiologic agent of the disease. SVV is antigenically and genetically related to varicella–zoster virus (VZV; Human herpesvirus 3), the cause of human varicella (chickenpox) and herpes zoster (shingles). The clinical similarities between simian and human varicella and the relatedness of SVV and VZV, indicate that SVV infection of nonhuman primates is a useful model for study of varicella pathogenesis and development of antiviral therapies. A previous comprehensive review emphasized simian varicella as an experimental model for VZV infections.22 This review focuses on simian varicella as a veterinary disease of nonhuman primates. Simian varicella outbreaks and their epidemiology are considered, and the etiologic agent, clinical manifestations, pathogenesis, diagnosis, treatment, and control of the disease are discussed. 相似文献
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J. P. SPRADBERY R. J. MAHON R. MORTON R. S. TOZER† 《Medical and veterinary entomology》1995,9(2):161-168
Abstract. Dispersal of the Old World screw-worm fly, Chrysomya bezziana Villeneuve, was studied in Papua New Guinea by releasing radio-isotope labelled, laboratory-reared flies and collecting their labelled egg masses from sentinel cattle. A log-linear model was developed to describe recapture rate. Distance was found to dominate the model and was represented by a bilinear ('broken-stick') term as log-distance. Further terms in the model such as attractiveness of the site (estimated from the number of non-labelled egg masses), the season of the year and a time trend were statistically significant but of minor importance. From the model, the median distance females dispersed before depositing an egg mass was 10.8 km. The maximum distance from the release site that egg masses were recovered was 100 km.
The dispersal ability of C. bezziana is discussed in terms of its impact on the prospects of eradicating this species using SIRM if an outbreak occurred in Australia. 相似文献
The dispersal ability of C. bezziana is discussed in terms of its impact on the prospects of eradicating this species using SIRM if an outbreak occurred in Australia. 相似文献
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Species of Dichromothrips are shown to be widespread on Orchidaceae in the Old World Tropics from Africa to New Zealand. The centre of diversity appears to be the Malaysian Region but this may be an artefact resulting from poor collections. The genus is redefined, its relationships discussed and a key provided to the 14 species [ australiae sp. nov., borneensis (Pr.); corbetti (Pr.); dendrobii Saki.; indicus sp. nov.; maori sp. nov.; nakahari sp. nov.; nigeriae sp. nov.; orchidis Pr.; phalaenopsidis Saki. (= sakimurai Bhatti syn.nov.); priesneri (Hood); semicognitus Saki.; smithi (Zimm.)j via torus sp. nov.|. Eugeneothrips Hood is synonymised with Dichromothrips. 相似文献
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R. C. Barneby 《Feddes Repertorium》1971,82(9):579-580
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B. Chiarelli 《Journal of human evolution》1973,2(4):307-310
Data on number and morphology of chromosomes on the Old World Primates suggest the existence of three major lines of chromosomal evolution. Connection among these three lines are hypothetized on the basis of a comparison of the so-called “marked” chromosomes. 相似文献
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Longitudinal ground sections of 29 Old World monkey central lower incisors were studied histologically and metrically. Labiolingual incisor width tended to scale isometrically with body weight but with important deviations in relative incisor size, which appeared to be correlated with diet in accord with work by Hylander. Lower incisors of the predominantly folivorous colobine monkeys had a substantial layer of enamel on both lingual and labial aspects and consequently had blunt incisal edges. These teeth in both cercopithecins and papionins, which are omnivorous or frugivorous, had little or no enamel on the lingual aspect, resulting in sharp incisal edges. It is suggested that colobine incisors are used mainly in gripping and tearing leaves, whereas cercopithecine incisors are better adapted to cutting and scraping. Crown height showed a positive allometric relationship with overall incisor height, so that the tall incisors of papionins, especially Papio and Mandrillus, were more hypsodont than the shorter incisors of colobines and cercopithecins. This appears to be related to differences in the rates of incisor wear between the groups. 相似文献
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《Ostrich》2013,84(3):277-278
The Kotoka International Airport in Accra, the capital city of Ghana, has in recent years been confronted with increased presence of birds posing great challenges to aviation safety due to a high risk of bird strikes. As part of measures to mitigate the negative impacts of increasing numbers of birds, a species-specific bird strike risk index (SSBR) was modelled and calculated for a total of 86 species recorded within and near the airport. Based on the SSBR index, four species were classified as ‘critical risk’ and another four species as ‘high risk’. All six species, namely Corvus albus, Necrosyrtes monachus, Milvus migrans parasitus, Bubulcus ibis, Falco biarmicus and Falco tinnunculus, constituting 7% of the total species assemblage, were considered ‘problem species’. During the intensive, albeit short, study period, we also recorded bird strikes of N. monachus, F. biarmicus and notably M. m. parasitus. We conclude that wildlife management to avert the risk of bird strikes could be successfully achieved by adopting both proactive and reactive measures to reduce the presence of problem species at the aerodrome. 相似文献
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Multiple introductions of the Old World begomovirus Tomato yellow leaf curl virus into the New World
A phylogenetic analysis of three genomic regions revealed that Tomato yellow leaf curl virus (TYLCV) from western North America is distinct from TYLCV isolated in eastern North America and the Caribbean. This analysis supports a second introduction of this Old World begomovirus into the New World, most likely from Asia. 相似文献
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Multiple Introductions of the Old World Begomovirus Tomato yellow leaf curl virus into the New World
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A phylogenetic analysis of three genomic regions revealed that Tomato yellow leaf curl virus (TYLCV) from western North America is distinct from TYLCV isolated in eastern North America and the Caribbean. This analysis supports a second introduction of this Old World begomovirus into the New World, most likely from Asia. 相似文献
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The use of the tail by an Old World monkey 总被引:1,自引:1,他引:0
Rathe Karrer 《Primates; journal of primatology》1970,11(2):171-175
The Old World monkeyMacaca irus has a semi-prehensile tail. Animals reared in the laboratory use the tail as a tool to facilitate interaction with the environment. This observation may have some significance in the evolution of Old and New World monkeys and the differentiation of species. 相似文献