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1.
Northeast India, the only region which currently forms a land bridge between the Indian subcontinent and Southeast Asia, has been proposed as an important corridor for the initial peopling of East Asia. Given that the Austro-Asiatic linguistic family is considered to be the oldest and spoken by certain tribes in India, Northeast India and entire Southeast Asia, we expect that populations of this family from Northeast India should provide the signatures of genetic link between Indian and Southeast Asian populations. In order to test this hypothesis, we analyzed mtDNA and Y-Chromosome SNP and STR data of the eight groups of the Austro-Asiatic Khasi from Northeast India and the neighboring Garo and compared with that of other relevant Asian populations. The results suggest that the Austro-Asiatic Khasi tribes of Northeast India represent a genetic continuity between the populations of South and Southeast Asia, thereby advocating that northeast India could have been a major corridor for the movement of populations from India to East/Southeast Asia.  相似文献   

2.
Ethnic populations of India as seen from an evolutionary perspective   总被引:5,自引:0,他引:5  
It is now widely accepted that (i) modern humans,Homo sapiens sapiens, evolved in Africa, (ii) migrated out of Africa and replaced archaic humans in other parts of the world, and (iii) one of the first waves of out-of-Africa migration came into India. India, therefore, served as a major corridor for dispersal of modern humans. By studying variation at DNA level in contemporary human populations of India, we have provided evidence that mitochondrial DNA haplotypes based on RFLPs are strikingly similar across ethnic groups of India, consistent with the hypothesis that a small number of females entered India during the initial process of the peopling of India. We have also provided evidence that there may have been dispersal of humans from India to southeast Asia. In conjunction with haplotype data, nucleotide sequence data of a hypervariable segment (HVS-1) of the mitochondrial genome indicate that the ancestors of the present austro-asiatic tribal populations may have been the most ancient inhabitants of India. Based on Y-chromosomal RFLP and STRP data, we have also been able to trace footprints of human movements from west and central Asia into India.  相似文献   

3.
The biogeographic and tectonic history of India   总被引:10,自引:0,他引:10  
Aim To present an up to date account of the Mesozoic history of India and its relationship to the other Gondwana continents and to Eurasia. Location Continents surrounding the Western Indian Ocean. Methods Utilization of recent evidence of continental relationships based upon research in stratigraphy, palaeomagnetism, palaeontology, and contemporary biotas. Results The physical data revealed a sequence of events as India moved northward: (1) India–Madagascar rifted from east Africa 158–160 Ma (million years ago), (2) India–Madagascar from Antarctica c. 130 Ma, (3) India–Seychelles from Madagascar 84–96 Ma, (4) India from Seychelles 65 Ma, (5) India began collision with Eurasia 55–65 Ma and (6) final suturing took place c. 42–55 Ma. However, data from fossil and contemporary faunas indicate that, throughout the late Cretaceous, India maintained exchanges with adjacent lands. There is an absence in the fossil record of peculiar animals and plants that should have evolved, had India undergone an extended period of isolation just before its contact with Eurasia. Main conclusions The depiction of India in late Cretaceous as an isolated continent is in error. Most global palaeomaps, including the most recent one, show India, as it moves northward, following a track far out in the Indian Ocean. But the evidence now indicates that India's journey into northern latitudes cannot have taken place under such isolated circumstances. Although real breaks among the lands were indicated by the physical data, faunal links were maintained by vagile animals that were able to surmount minor marine barriers. India, during its northward journey, remained close to Africa and Madagascar even as it began to contact Eurasia.  相似文献   

4.
Abstract

Begomoviruses are major constraint in tomato production across the world. In India, tomato production is affected by both monopartite and bipartite begomoviruses. Monopartite were reported to infect tomato crop across India. However, bipartite were reported to infect tomato in Nothern India. In the current study, seventy begomovirus symptomatic tomato samples were collected from southernstates of India and analysed using PCR-based specific primer. The analysis revealed that 45 of them were monopartite, 23 of them were bipartite and 8 bipartite also showed the presence of betasatellite. This is the first report of bipartite begomovirus infecting tomato in Southern India.  相似文献   

5.
本文根据猪屎豆属植物的外部形态和细胞染色体特征以及地理分布特点,论述了该属植物的起源、发展和迁移等问题;并运用组相似性和种相似性分析方法,论证了非洲、马达加斯加和印度之间,以及印度与其在亚洲的邻近地区之间在种类组成上的共有关系和亲缘关系。本文还侧重于该属植物在云南的分布格局,提出它们从印度向中国散布的可能存在路线。  相似文献   

6.
Tissue samples from 699 birds from three regions of Asia (Myanmar, India, and South Korea) were screened for evidence of infection by avian parasites in the genera Plasmodium and Haemoproteus. Samples were collected from November 1994 to October 2004. We identified 241 infected birds (34.0%). Base-on-sequence data for the cytochrome b gene from 221 positive samples, 34 distinct lineages of Plasmodium, and 41 of Haemoproteus were detected. Parasite diversity was highest in Myanmar followed by India and South Korea. Parasite prevalence differed among regions but not among host families. There were four lineages of Plasmodium and one of Haemoproteus shared between Myanmar and India and only one lineage of Plasmodium shared between Myanmar and South Korea. No lineages were shared between India and South Korea, although an equal number of distinct lineages were recovered from each region. Migratory birds in South Korea and India originate from two different migratory flyways; therefore cross-transmission of parasite lineages may be less likely. India and Myanmar shared more host species and habitat types compared to South Korea. Comparison between low-elevation habitat in India and Myanmar showed a difference in prevalence of haematozoans.  相似文献   

7.
The Gaur Bos gaurus ranges from India to peninsular Malaysia. Its distribution, status and conservation in the Indian subcontinent are reviewed here on the basis of available information, both published papers and unpublished census reports of forest departments, and field survey data from north‐eastern India and parts of Bhutan and Nepal. The Gaur is found in three disjunct regions, south‐western India, central India and north‐eastern India (including Nepal, Bhutan and Bangladesh). Within these regions the distribution is highly fragmented and includes a number of small non‐viable isolated populations. The habitat in north‐eastern India is still contiguous with that in Bhutan, Myanmar and Bangladesh and to some extent with Nepal. Although the estimated population of the Gaur is 23 000–34 000, it is declining alarmingly. Populations outside the protected areas may not last long. An action plan has been proposed for its conservation.  相似文献   

8.
Bu CP  Liang AP 《ZooKeys》2011,(81):1-12
Aprivesa unimaculatasp. n. (Hemiptera: Fulgoromorpha: Ricaniidae) is described and illustrated from Coorg, south India. This represents the first record of the genus Aprivesa Melichar from India and the fourth known species of Aprivesa. The new taxon greatly extends the range of the genus Aprivesa, which was previously known as an endemic Australian genus. A checklist of all known species of the Ricaniidae from India and keys to all the known genera of the Ricaniidae from India and all species in the genus are provided.  相似文献   

9.
Inferring the origin and dispersal of the chloroquine-resistant (CQR) malaria parasite, Plasmodium falciparum, is of academic and public health importance. The Pfcrt gene of P. falciparum is widely known as the CQR gene and two major haplotypes of this gene (CVIET and SVMNT) occur widely across CQR-endemic regions of the globe. In India, studies to date of the Pfcrt gene have indicated the widespread prevalence of the SVMNT haplotype (prevalent in the South America and Papua New Guinea), whereas the CVIET haplotype, primarily found in southeast Asia, was not detected at a high frequency in India. This distribution pattern of the two most common CQR-Pfcrt haplotypes in India is quite surprising. Thus, in order to understand probable evolutionary and migration patterns of the CQR-Pfcrt haplotypes into India, we generated new sequence data of exon 2 of the Pfcrt gene and collected published information on the CQR-Pfcrt haplotype data from India, Papua New Guinea, southeast Asia and South America, and performed several population and evolutionary genetic analyses. Among several interesting findings, statistically significant longitudinal clines for the CVIET and SVMNT haplotypes (in opposite directions) in India, and the clustering of India and Papua New Guinea under the SVMNT-specific clade in the phylogenetic tree, are the two most remarkable aspects of the data. It also appears that both the SVMNT and CVIET haplotypes in India have migrated from southeast Asia. In particular, whereas the Indian CVIET haplotype has a southeast Asian origin, the SVMNT haplotype, prevalent in India, seems to have originated in Papua New Guinea and entered India through southeast Asia.  相似文献   

10.
To determine the origin of sickle cell anemia (SS) in India, we analyzed haplotypes of the beta gene cluster in beta S-carrying individuals belonging to tribal populations living in the Nilgiris region of southern India and complemented the available data on tribes of east-central India. We found that in the Nilgiris tribes chromosomes bearing the beta S gene are linked in 91% of the cases to the "Asian" (Arab-Indian) haplotype (although 25% of the haplotypes had the epsilon polymorphic site negative, making the 5' portion of the haplotype identical with the African Senegal haplotype). These XmnI (+) chromosomes were associated with high G gamma expression (67.2 +/- 5.9%) and a high percentage of Hb F (15.5 +/- 7.9%; range, 6-25.3%). We have similar findings for tribal groups from west-central India (Gujarat). In east-central India we have confirmed the data of others, finding the same haplotype linked to beta S in tribes living in the east (Orissa, Andhra Pradesh). We conclude that the beta S gene in presently isolated and disperse tribal populations in India is associated with one predominant typical haplotype, suggesting a unicentric origin of the mutation in India. In addition, this finding implies a unicentric origin of the tribal populations themselves: The gene must have arisen and spread before tribal dispersion. Furthermore, we find extremely high frequencies of the (-alpha) haplotype in the Nilgiris (0.89) and in Gujarat (0.95). The beta S gene linkage to a high Hb F-expressing haplotype and the high incidence of alpha-thalassemia predict a mild phenotypical expression of sickle cell anemia in India.  相似文献   

11.
Karnal bunt of wheat, caused byNeovossia indica (Mitra) Mundkur, was first reported in 1931 from Northwestern India in experimental plantings. For many years it was a minor disease found only in Northwestern India. During the 1969–70 crop season it was unusually widespread in Northwest India and since 1974–75 Karnal bunt has been distributed throughout Northern India from West Bengal to the western border. Seed lots with more than 50% of the kernels infected have been collected from farm threshing sites. The disease is now established in Afghanistan, Iraq, Pakistan and Mexico and has been intercepted in India in wheat seed that was shipped from Lebanon and Syria. The increased geographic distribution of Karnal bunt may be due to the development and wide distribution of wheat cultivars that were more susceptible than the older wheats that were grown in India prior to 1969–70. Resistance to Karnal bunt has been reported in several Indian wheats but most cultivars are susceptible. Hexachlorobenzene and cyano (methylmercuric) guanidine each prevented germination of teliospores ofN. indica in tests in Mexico.  相似文献   

12.
India is predominantly an agricultural country with about 70% of her population dependent on income from agriculture. Although India accounts for a significant share of world’s livestock resources, livestock production is greatly affected by ticks and tick-borne diseases (TTBDs). Therefore, India represents a particularly interesting scenario for the study of TTBDs. Herein, we review the problems and opportunities for the integrated control of ticks of ruminants with special emphasis on livestock farming systems in India. Developments discussed in the review in the area of tick vaccines and other tick control measures should have an impact on the future of Indian livestock production.  相似文献   

13.
Rotifers from Andhra Pradesh, India   总被引:3,自引:0,他引:3  
The present communication deals with 11 species of rotifers from Andhra Pradesh, India belonging to six genera and three families (Notommatidae, Dicranophoridae and Asplanch-nidae) including a new species Asplanchnopus bhimavaramensis , together with a key for the identification of species of the genus Asplanchnopus. All the species described are new to South India, four of them being reported for the first time from India.  相似文献   

14.
Krithika S  Maji S  Vasulu TS 《PloS one》2008,3(7):e2549
Tibeto-Burman populations of India provide an insight into the peopling of India and aid in understanding their genetic relationship with populations of East, South and Southeast Asia. The study investigates the genetic status of one such Tibeto-Burman group, Adi of Arunachal Pradesh based on 15 autosomal microsatellite markers. Further the study examines, based on 9 common microsatellite loci, the genetic relationship of Adi with 16 other Tibeto-Burman speakers of India and 28 neighboring populations of East and Southeast Asia. Overall, the results support the recent formation of the Adi sub-tribes from a putative ancestral group and reveal that geographic contiguity is a major influencing factor of the genetic affinity among the Tibeto-Burman populations of India.  相似文献   

15.
Mycobacterium leprae, an infectious agent of chronic infection so-called Leprosy. It is a prime healthconcern in various countries including India. India i  相似文献   

16.
The present study deals with the effect of migration on the adult body dimensions among the Oraons of Estern India. The study was conducted on the 232 sedente Oraon of both sexes from Gumla district, Bihar, India and their 230 migrant counter-parts of both sexes from the tea gardens in Duars are, Jalpaiguri district, West Bengal, India. The results show that the migrants are lighter and slightly shorter.  相似文献   

17.
Geophysical maps depicting continental movement have consistently shown India, as it moved northward, to be located far out in the Tethys Sea. India split off from the African east coast about 148 m.y.a. From that time onward, according to almost all geophysical accounts, India was isolated from all of other continents until the early Miocene when it made contact with Eurasia. But the biological data, both fossil and Recent, indicate that this concept cannot be correct. If India had really existed as an isolated, oceanic continent for about 100 m.y., it should have developed a peculiar biota with many endemic genera and families in its terrestrial and shallow marine habitats. But there are virtually no remains of organisms indicating that India was isolated for any substantial time (millions of years). Instead, we find that almost all Indian taxa were possessed in common with other continents. As time went on, the northern relationships became stronger and the southern ones weaker. Most of the recent geophysical accounts show India not making contact with Eurasia until the early Miocene, but fossil materials show that this event must have taken place by the early Eocene. It has been postulated that, as India moved northward, it created a biogeographic barrier that separated marine fish populations and resulted in the east-west provinces that are now apparent in the Indian Ocean. At the same time, the barrier effect was supposed to have resulted in the formation of sister species that are now located far apart. Information currently available indicates that most living, tropical marine species are probably not over 3 m.y. old. Consequently, the northward movement of India, which took place primarily between 148 and 50 m.y.a., could have no bearing on the relationships of modern species.  相似文献   

18.
印度是世界上生物多样性最丰富的国家之一,主张遗传资源主权归国家所有并实现遗传资源惠益公平分享。印度政府于2003年颁布了《生物多样性法》,2004年又补充颁布了《生物多样性条例》,明确规定国家对其生物资源及相关传统知识的主权、保护原则、主管部门和管理体系、获取和惠益分享等问题。2014年又制订发布了《生物资源及相关传统知识获取规则指南》,对生物考察和利用、商业开发的惠益形式与比例、成果转化程序与惠益分享方式、知识产权获取程序与惠益分享形式、第三方转让为研究或商业利用、豁免审批情况等都作出了详细明确的规定。从印度遗传资源获取与惠益分享制度体系发展动态来看,印度的制度构建过程是循序渐进,不断更新,逐步趋于完善、细化。印度的遗传资源制度体系建设紧跟国际发展形势,从原则性的规定发展到具体措施。印度与中国生物遗传资源及相关传统知识国情相似,国际谈判立场一致,印度的遗传资源获取与惠益分享管理制度体系构建思路值得中国在国内遗传资源获取与惠益分享国家制度体系构建借鉴。  相似文献   

19.
It is hypothesized that the ancestor of the extant western Indian Ocean and Indonesian populations of Latimeria was continuously distributed along the deeper coasts of massed Africa–Madagascar–Eurasia in early geologic time. The collision of India with Eurasia, roughly 50 MY ago, caused the formation of the Himalayan Mountains and subsequent developement of numerous rivers. The rivers, which flow down both coasts of India, and areas even further east, deposited, and continue to deposit, great amounts of silt along both coasts of India. The siltation destroyed possible coelacanth habitats, thus isolating coelacanth populations to the west of India from those to the east and allowing them to diverge.  相似文献   

20.
B. K. Sharma 《Hydrobiologia》1981,76(3):249-253
This communication deals with an account of 20 species (spread over four genera) belonging to the family Brachionidae, collected from various localities in Panjab State (N. W. India). A number of infraspecific categories (forms and varieties) are also recorded. The present study has added 8 taxa as new records to the list of previously recorded brachionid rotifers from N. W. India and one represents a new record from India.  相似文献   

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