Biogeography of Southeast Asia and the West Pacific

The biogeography of Southeast Asia and the West Pacific is complicated by the fact that these are regions on the border of two palaeocontinents that have been separated for a considerable period of time. Thus, apart from any patterns of vicariance, two general patterns relating to dispersal can be expected: a pattern of Southeast Asian elements, perhaps of Laurasian origin, expanding into Australian areas, and a reverse pattern for Australian elements, perhaps of Gondwanan origin. On top of this, both Australian and Southeast Asian elements occur in the Pacific. They dispersed there as the Pacific plate moved westward, bringing the different islands within reach of Southeast Asia and Australia. In order to reconstruct the biotic history of these areas, two large data sets consisting of both plants and animals were generated, one for each pattern, which were analysed using cladistic methods. The general patterns that emerged were weakly supported and do not allow general conclusions.     

Mitochondrial DNA data indicate an introduction through Mainland Southeast Asia for Australian dingoes and Polynesian domestic dogs

In the late stages of the global dispersal of dogs, dingoes appear in the Australian archaeological record 3500 years BP, and dogs were one of three domesticates brought with the colonization of Polynesia, but the introduction routes to this region remain unknown. This also relates to questions about human history, such as to what extent the Polynesian culture was introduced with the Austronesian expansion from Taiwan or adopted en route, and whether pre-Neolithic Australia was culturally influenced by the surrounding Neolithic world. We investigate these questions by mapping the distribution of the mtDNA founder haplotypes for dingoes (A29) and ancient Polynesian dogs (Arc1 and Arc2) in samples across Southern East Asia (n = 424) and Island Southeast Asia (n = 219). All three haplotypes were found in South China, Mainland Southeast Asia and Indonesia but absent in Taiwan and the Philippines, and the mtDNA diversity among dingoes indicates an introduction to Australia 4600-18 300 years BP. These results suggest that Australian dingoes and Polynesian dogs originate from dogs introduced to Indonesia via Mainland Southeast Asia before the Neolithic, and not from Taiwan together with the Austronesian expansion. This underscores the complex origins of Polynesian culture and the isolation from Neolithic influence of the pre-Neolithic Australian culture.     

Metric analyses of an Early Holocene human skeleton from Gua Gunung Runtuh,Malaysia

A nearly complete human skeleton dating to the Early Holocene (epi-Paleolithic culture) excavated from Gua Gunung Runtuh, Malaysia, is described. Cranial, dental, and limb bone measurements are recorded on the skeleton, and compared with early and modern skeletal samples from Southeast Asia and Australia. The comparisons demonstrate that the Gua Gunung specimen is most similar to Australian Aborigines in dental and limb measurements, while the cranial measurements indicate a close affinity to Mesolithic samples from Malaysia and Flores. These findings further suggest that the Gua Gunung skeleton, as well as other fossils from Tabon and Niah, are representative of an early group of people who occupied Sundaland during the late Pleistocene, and may be the ancestors of Australian Aborigines. Some of the dental and limb bone measurements exhibited by the ancestors persist in Southeast Asian populations until the early Holocene. Differences in cranial traits have, however, accumulated since the late Pleistocene in Australian Aborigines and early Southeast Asian peoples. Am J Phys Anthropol 109:327–340, 1999. © 1999 Wiley-Liss, Inc.     

Determining biogeographical patterns of dispersal and diversification in oscine passerine birds in Australia, Southeast Asia and Africa

Aim  Several independent studies suggest that oscine passerine birds originated in Eastern Gondwana/Australia and from there spread to Southeast Asia and then to Africa. A recently constructed supertree including 1724 oscine taxa forms the basis for this study, in which we present a more detailed hypothesis of this out-of-Australia scenario.
Location  Australia, Africa, Southeast Asia, western Pacific, Indian Ocean.
Methods  We used the computer program DIVA to identify putative ancestral areas for each node. We also applied a molecular clock calibrated with three recently conducted studies of passerines to estimate the ages of basal nodes. Although these time estimates are rough they give some indication that, together with the putative ancestral areas, they can be compared with known events of plate tectonic movements in the Australian, Southeast Asian and western Pacific regions.
Results  The DIVA analysis shows that Basal Corvida and Crown Corvida originated in Australia. Ancestral nodes for Picathartes / Chaetops and Passerida originated in Africa, and the basal nodes of Sylvioidea also originated in Africa. For Muscicapoidea and Passeroidea we were unable to establish ancestral patterns. The molecular clock showed that Crown Corvida radiated between 20 and 30 Ma whereas Basal Corvida and the Passerida clade radiated from c . 45 to 50 Ma.
Main conclusions  Both approaches agree that: (1) Crown Corvida spread from Australia to Southeast Asia, with several dispersal events around the time when the terranes of Australian and Indomalayan origin came close together some 15 Ma, and (2) a single dispersal event went from Australia across the Indian Ocean to Africa c . 45–50 Ma, leading to the very large radiation of the parvorder Passerida. The latter hypothesis is novel, and contrary to the general view that oscines spread exclusively via Southeast Asia.     

Negritos, Australian aborigines, and the "proto-sundadont" dental pattern: the basic populations in east Asia, V.

Five evolutionarily significant dental traits were identified from a B-square distance analysis of nine crown characters recorded for several populations of East Asia and Oceania. Intergroup variation in these traits distinguishes three major divisions of the Mongoloid dental complex: sundadonty, sinodonty, and the dental pattern of Australian Aborigines. The Australian crown features may be characterized as having high frequencies of evolutionarily conservative characters. Negritos, one of the probable representatives of indigenous inhabitants of Southeast Asia who may have shared a common ancestor with Australians, possess the more derived sundadont dental pattern. As far as the five crown traits treated here are concerned, Australian dental features may be described as conforming to a "proto-sundadont" dental pattern, applying Turner's terminology. This pattern may represent a microevolutionary step prior to the emergence of the sundadont and sinodont patterns.     

Independent maternal origin of Chinese swamp buffalo (Bubalus bubalis)

To obtain more knowledge on the origin and genetic diversity of the swamp buffalo (Bubalus bubalis) in China, the complete mitochondrial D-loop sequences of 119 samples representing seven native types were compared. Two mitochondrial DNA (mtDNA) lineages (lineages A and B) were determined for the Chinese swamp buffalo. Examination of the diversity patterns suggest that lineage A has undergone a population expansion event. Divergence of lineages A and B was estimated at 18,000 years ago. Combined analyses of mtDNA sequences from Chinese, Indian, Brazilian/Italian and Southeast Asian/Australian buffalo samples showed independent domestication events in the swamp buffalo from China and the river buffalo from the India subcontinent. The spread of swamp and river buffalo from China and India respectively to mainland Southeast Asia suggests that Southeast Asia is a hybrid zone for buffalo. Our data support the hypothesis of the evolution of domesticated swamp and river buffalo from ancestral swamp-like animals. These ancestral animals were extensively distributed across mainland Asia and most likely are represented today by the wild Asian buffalo (Bubalus arnee).     

A morphometric analysis of the Late Pleistocene Human Skeleton from the Moh Khiew Cave in Thailand.

Few Late Pleistocene human remains have been found in Southeast Asia and the morphological features of the people of that age are still largely unknown due to the virtual lack of human remains in the area. Recent excavations at the Moh Khiew Cave in Thailand resulted in the discovery of a Late Pleistocene human skeleton in a relatively good state of preservation. An AMS radiocarbon date on the charcoal sample gathered from the burial gave a result of 25,800 +/- 600 BP, implying that the inhabitants of Moh Khiew Cave resided in a part of Sundaland during the last glacial age. In debates on the population history of Southeast Asia, it has been repeatedly advocated that Southeast Asia was occupied by indigenous people akin to present-day Australo-Melanesians prior to an expansion of migrants from Northeast Asia into this area. Morphometric analyses were undertaken to test the validity of this hypothesis. In the present study, cranial and dental measurements recorded from the Moh Khiew remains are compared with those of early and modern samples from Southeast Asia and Australia. These comparisons demonstrate that the Moh Khiew specimen resembles the Late Pleistocene series from Coobool Creek, Australia in both cranial and dental measurements. These results suggest that the Moh Khiew skeleton, as well as other fossil remains from the Tabon, Niah and Gua Gunung sites, represents a member of the Sundaland population during the Late Pleistocene, who may share common ancestry with the present-day Australian Aborigines and Melanesians.     

Merit and Blessing in Mainland Southeast Asia in Comparative Perspective

Merit and Blessing in Mainland Southeast Asia in Comparative Perspective. Cornelia Ann Kammerer and Nicola Tannenbaum. eds. Yale Southeast Asia Studies, 45. New Haven, CT: Yale University Southeast Asia Studies, 1996. 263 pp.     

Phylogenetic distinctiveness of Middle Eastern and Southeast Asian village dog Y chromosomes illuminates dog origins

Modern genetic samples are commonly used to trace dog origins, which entails untested assumptions that village dogs reflect indigenous ancestry or that breed origins can be reliably traced to particular regions. We used high-resolution Y chromosome markers (SNP and STR) and mitochondrial DNA to analyze 495 village dogs/dingoes from the Middle East and Southeast Asia, along with 138 dogs from >35 modern breeds to 1) assess genetic divergence between Middle Eastern and Southeast Asian village dogs and their phylogenetic affinities to Australian dingoes and gray wolves (Canis lupus) and 2) compare the genetic affinities of modern breeds to regional indigenous village dog populations. The Y chromosome markers indicated that village dogs in the two regions corresponded to reciprocally monophyletic clades, reflecting several to many thousand years divergence, predating the Neolithic ages, and indicating long-indigenous roots to those regions. As expected, breeds of the Middle East and East Asia clustered within the respective regional village dog clade. Australian dingoes also clustered in the Southeast Asian clade. However, the European and American breeds clustered almost entirely within the Southeast Asian clade, even sharing many haplotypes, suggesting a substantial and recent influence of East Asian dogs in the creation of European breeds. Comparison to 818 published breed dog Y STR haplotypes confirmed this conclusion and indicated that some African breeds reflect another distinct patrilineal origin. The lower-resolution mtDNA marker consistently supported Y-chromosome results. Both marker types confirmed previous findings of higher genetic diversity in dogs from Southeast Asia than the Middle East. Our findings demonstrate the importance of village dogs as windows into the past and provide a reference against which ancient DNA can be used to further elucidate origins and spread of the domestic dog.     

Mitochondrial DNA variation in Nicobarese Islanders.

The aboriginal populations living in the Nicobar Islands are hypothesized to be descendants of people who were part of early human dispersals into Southeast Asia. However, analyses of ethnographic histories, languages, morphometric data, and protein polymorphisms have not yet resolved which worldwide populations are most closely related to the Nicobarese. Thus, to explore the origins and affinities of the Nicobar Islanders, we analyzed mitochondrial DNA (mtDNA) hypervariable region 1 sequence data from 33 Nicobarese Islanders and compared their mtDNA haplotypes to those of neighboring East Asians, mainland and island Southeast Asians, Indians, Australian aborigines, Pacific Islanders, and Africans. Unique Nicobarese mtDNA haplotypes, including five Nicobarese mtDNA haplotypes linked to the COII/tRNA(Lys) 9-bp deletion, are most closely related to mtDNA haplotypes from mainland Southeast Asian Mon-Kmer-speaking populations (e.g., Cambodians). Thus, the dispersal of southern Chinese into mainland Southeast Asia may have included a westward expansion and colonization of the islands of the Andaman Sea.     

Y-chromosome and mitochondrial DNA studies on the population structure of the Christmas Island community

Christmas Island is a remote Australian territory located close to the main Indonesian island of Java. Y-chromosome and mitochondrial DNA (mtDNA) markers were used to investigate the genetic structure of the population, which comprises communities of mixed ethnic origin. Analysis of 12 Y-chromosome biallelic polymorphisms revealed a high level of gene diversity and haplotype frequencies that were consistent with source populations in southern China and Southeast Asia. mtDNA hypervariable segment I (HVS-I) sequences displayed high levels of haplotype diversity and nucleotide diversity that were comparable to various Asian populations. Genetic distances revealed extremely low mtDNA differentiation among Christmas Islanders and Asian populations. This was supported by the relatively high proportion of sequence types shared among these populations. The most common mtDNA haplogroups were M* and B, followed by D and F, which are prevalent in East/Southeast Asia. Christmas Islanders of European descent were characterized by the Eurasian haplogroup R*, and a limited degree of admixture was observed. In general, analysis of the genetic data indicated population affinities to southern Chinese (in particular from the Yunnan Province) and Southeast Asia (Thailand, Malaysia, and Cambodia), which was consistent with historical records of settlement. The combined use of these different marker systems provides a useful and appropriate model for the study of contemporary populations derived from different ethnic origins.     

Pliocene climatic change in insular Southeast Asia as an engine of diversification in Ficedula flycatchers

Aims Insular Southeast Asia and adjacent regions are geographically complex, and were dramatically affected by both Pliocene and Pleistocene changes in climate, sea level and geology. These circumstances allow the testing of several biogeographical hypotheses regarding species distribution patterns and phylogeny. Avian species in this area present a challenge to biogeographers, as many are less hindered by barriers that may block the movements of other species. Widely distributed Southeast Asian avian lineages, of which there are many, have been generally neglected. Ficedula flycatchers are distributed across Eurasia, but are most diverse within southern Asia and Southeast Asian and Indo‐Australian islands. We tested the roles of vicariance, dispersal and the evolution of migratory behaviours as mechanisms of speciation within the Ficedula flycatchers, with a focus on species distributed in insular Southeast Asia. Methods Using a published molecular phylogeny of Ficedula flycatchers, we reconstructed ancestral geographical areas using dispersal vicariance analysis, weighted ancestral area analysis, and a maximum likelihood method. We evaluated the evolution of migratory behaviours using maximum likelihood ancestral character state reconstruction. Speciation timing estimates were calculated via local molecular clock methods. Results Ficedula originated in southern mainland Asia, c. 6.5 Ma. Our analyses indicate that two lineages within Ficedula independently and contemporaneously colonized insular Southeast Asia and Indo‐Australia, c. 5 Ma. The potential impact of vicariance due to rising sea levels is difficult to assess in these early colonization events because the ancestral areas to these clades are reconstructed as oceanic islands. Within each of these clades, inter‐island dispersal was critical to species’ diversification across oceanic and continental islands. Furthermore, Pliocene and Pleistocene climatic change may have caused the disjunct island distributions between several pairs of sister taxa. Both vicariance and dispersal shaped the distributions of continental species. Main conclusions This study presents the first evaluation, for Ficedula, of the importance of vicariance and dispersal in shaping distributions, particularly across insular Southeast Asia and Indo‐Australia. Although vicariant speciation may have initially separated the island clades from mainland ancestors, speciation within these clades was driven primarily by dispersal. Our results contribute to the emerging body of literature concluding that dynamic geological processes and climatic change throughout the Pliocene and Pleistocene have been important factors in faunal diversification across continental and oceanic islands.     

Historical biogeography of Southeast Asia and the West Pacific,or the generality of unrooted area networks as historical biogeographic hypotheses

Aim Unrooted area networks are perhaps a general way in which different historical biogeographical patterns may be combined. Location Southeast Asia up to the West Pacific, Australia, South America. Methods Unrooted area networks based on Primary Brooks Parsimony Analysis of different data sets of Southeast Asian–West Pacific, Australian and South American clades. Results A large Brooks Parsimony historical (cladistic) biogeographic analysis of Southeast Asia and the West Pacific gave a meaningful result when all clades (representing different historical biogeographic patterns) were united into one matrix and an unrooted area network was produced. This network showed geographically adjacent areas as neighbours, which is interpreted as clades dispersing and speciating as soon as areas rafted towards each other. This pseudo‐vicariance mechanism, together with the very limited, mainly linear dispersal possibilities, a few large, widespread clades with many endemic species, and the large overlap in distributions displayed by different patterns, may explain the peculiar result. When applied to examples from other areas (bird data from Australia and South America), unrooted area networks for all data perform very poorly. Main conclusions Unrooted historical general area networks are not universally applicable. In general, it is better to split historical patterns a priori and analyse them separately.     

Deforestation rates in insular Southeast Asia between 2000 and 2010

Insular Southeast Asia experienced the highest level of deforestation among all humid tropical regions of the world during the 1990s. Owing to the exceptionally high biodiversity in Southeast Asian forest ecosystems and the immense amount of carbon stored in forested peatlands, deforestation in this region has the potential to cause serious global consequences. In this study, we analysed deforestation rates in insular Southeast Asia between 2000 and 2010 utilizing a pair of 250 m spatial resolution land cover maps produced with regional methodology and classification scheme. The results revealed an overall 1.0% yearly decline in forest cover in insular Southeast Asia (including the Indonesian part of New Guinea) with main change trajectories to plantations and secondary vegetation. Throughout the region, peat swamp forests experienced clearly the highest deforestation rates at an average annual rate of 2.2%, while lowland evergreen forests declined by 1.2%/yr. In addition, the analysis showed remarkable spatial variation in deforestation levels within the region and exposed two extreme concentration areas with over 5.0% annual forest loss: the eastern lowlands of Sumatra and the peatlands of Sarawak, Borneo. Both of these areas lost around half of their year 2000 peat swamp forest cover by 2010. As a whole this study has shown that deforestation has continued to take place on high level in insular Southeast Asia since the turn of the millennium. These on‐going changes not only endanger the existence of numerous forest species endemic to this region, but they further increase the elevated carbon emissions from deforested peatlands of insular Southeast Asia thereby directly contributing to the rising carbon dioxide concentration in the atmosphere.     

Genetic affinities of oceanic populations based on RFLP and haplotype analysis of genetic loci on three chromosomes.

Restriction fragment length polymorphisms at the renin and factor 13B loci located at chromosome 1q32-1q42 were studied in 14 ethnic groups in the west Pacific region. The allele frequencies were combined with previously described beta-globin and albumin-vitamin D binding protein haplotype frequencies and used to assess genetic affinities among eight major ethnic-geographic groups in this region. These population groups divide into two clusters with Australian Aborigines, Island Melanesians, and Highland Melanesians forming one cluster and east Asians, Southeast Asians, Micronesians, and Polynesians forming the other. The results indicate that Micronesians and Polynesians are derived from populations in Southeast Asia and that they originated independently of the Melanesian populations.     

Historical biogeography and phenotype‐phylogeny of Chroodiscus (lichenized Ascomycota: Ostropales: Graphidaceae)

Aim To analyse the historical biogeography of the lichen genus Chroodiscus using a phenotype‐based phylogeny in the context of continental drift and evolution of tropical rain forest vegetation. Location All tropical regions (Central and South America, Africa, India, Southeast Asia, north‐east Australia). Methods We performed a phenotype‐based phylogenetic analysis and ancestral character state reconstruction of 14 species of the lichen genus Chroodiscus, using paup * and mesquite ; dispersal–vicariance analysis (DIVA) and dispersal–extinction–cladogenesis (DEC) modelling to trace the geographical origin of individual clades; and ordination and clustering by means of pc‐ord , based on a novel similarity index, to visualize the biogeographical relationships of floristic regions in which Chroodiscus occurs. Results The 14 species of Chroodiscus show distinctive distribution patterns, with one pantropical and one amphi‐Pacific taxon and 12 species each restricted to a single continent. The genus comprises four clades. DIVA and DEC modelling suggest a South American origin of Chroodiscus in the mid to late Cretaceous (120–100 Ma), with subsequent expansion through a South American–African–Indian–Southeast Asian–Australian dispersal route and late diversification of the argillaceus clade in Southeast Asia. Based on the abundance of extant taxa, the probability of speciation events in Chroodiscus is shown to be extremely low. Slow dispersal of foliicolous rain forest understorey lichens is consistent with estimated phylogenetic ages of individual species and with average lengths of biological species intervals in fungi (10–20 Myr). Main conclusions The present‐day distribution of Chroodiscus can be explained by vicariance and mid‐distance dispersal through the interconnection or proximity of continental shelves, without the need for recent, trans‐oceanic long‐distance dispersal. Phylogenetic reconstruction and age estimation for Chroodiscus are consistent with the ‘biotic ferry’ hypothesis: a South American origin and subsequent eastward expansion through Africa towards Southeast Asia and north‐eastern Australia via the Indian subcontinent. The present‐day pantropical distributions of many clades and species of foliicolous lichens might thus be explained by eastward expansion through continental drift, along with the evolution of modern rain forests starting 120 Ma, rather than by the existence of a hypothetical continuous area of pre‐modern rain forest spanning South America, Africa and Southeast Asia during the mid and late Cretaceous.     

Population Structure of Wild Musk Shrews (Suncus murinus) in Asia Based on Mitochondrial DNA Variation, with Research in Cambodia and Bhutan

The musk shrew (Suncus murinus) is a small mammalian species belonging to Insectivora. It is widely distributed in Asia. To identify the genetic relationship among wild musk shrew populations and examine its migration route, we investigated the populations of Cambodia and Bhutan by using mitochondrial DNA restriction fragment length polymorphism analysis and compared them with other Asian populations previously described. Four haplotypes were detected in Cambodia and eight in Bhutan. A total of 53 haplotypes were detected in Asia and were classified largely into two groups, the Continental and Island types, based on a minimum spanning network. From the distribution of mtDNA types in wild musk shrews, three major population groups are identified in Asia: South Asia, Southeast Asia, and Malay. It is suggested that the Malay population group was a mix of South and Southeast Asian population groups and that this was a contact area of the two groups. In addition, other contact areas between the South and Southeast Asian groups exist in Myanmar, but unlike the Malay, the Myanmar area was the border of these groups.     

Phenetic relationships among varanid lizards based upon comparative electrophoretic data and karyotypic analyses

Comparative electrophoretic phenotypes of 18 of the 32 species of the lizard genus Varanus have been determined for four proteins. The animals studied were representative of species from Africa, Israel, Southeast Asia and Australia. Malate dehydrogenase (A₂) exhibited a single phenotype throughout. Lactate dehydrogenase (B₄) showed four distinctive electrophoretic forms which grouped the various subgenera as follows: (1) Polydaedalus, Empagusia (African); (2) Psammosaurus (Israel); (3) three species of Varanus, V. gouldii, V. spenceri, V. mertensi (Australian); (4) Dendrovaranus, Indovaranus (Southeast Asian), other Varanus species, Odatria (Australian). Electrophoretic and previously reported karyotypic data were used to interpret the phylogenetic relationships as well as the mode and direction of evolution of these animals. In particular, the results questioned the reality of the subgenus Varanus as a taxonomic unit, since four distinct karyotypic forms and two LDH-B₄ phenotypes were observed for these animals, of which one belongs to another subgenus. Serum albumin and carbonic anhydrase phenotypes were of little use in deciding phenotypic groupings.     

Zoogeography of the Southeast Asian Rotifera

The distribution and taxonomic composition of Rotifera in Southeast Asia is reviewed. For some countries, records are poor: Brunei, Cambodia and Laos are almost terra incognitafor rotifers (<10 taxa recorded), while the Thai rotifer fauna is the best documented (ca. 310 taxa on record). However, analysis of the available data is impeded by fuzzy taxonomy and the questionable reliability of many records. Most studies focus on the pelagic or littoral of freshwater habitats. Other habitats are largely ignored. Similarly, few studies deal comprehensively with illoricate Monogononta, sessile Flosculariacea and Collothecacea and, especially, Bdelloidea. The genera Lecane, Brachionus and Trichocerca are the best represented, with littoral taxa predominant. Fisheries-related studies dealing with highly productive pelagic environments tend to over report the contribution of Brachionus. Most taxa are thermophilic character, exemplified by the dominance of tropic-centred Lecaneand Brachionus. Some cold-water taxa have been recorded, but the relative climatological homogeneity of the region and low number of studies on high-altitude environments prevent the discrimination of clear latitudinal or altitudinal variation in the distribution of rotifers within Southeast Asia. The majority of Southeast Asian rotifers are widely distributed, including true cosmopolites and thermophilic taxa. There are several local or Oriental endemic Rotifera, mostly Lecane. The American Brachionus havanaensis and Keratella americana appear to have been introduced to the region. The taxonomy of some Rotifera described from the region is commented upon; Brachionus murphyiSudzuki is recognised as senior synonym of B. niwati Sanoamuang et al. (syn. nov.). Some cases of geographical and/or ecological vicariant species-pairs are suggested. The Southeast Asian rotifer fauna contains a sizeable fraction of taxa occurring in the tropical regions of the Old World, most of which also occur in tropical Australia or the Austro-Malayan region. A tropical Australasian faunal component is present, but consists of few taxa only. Hence, affinities between the rotifer fauna of the Ethiopian, Oriental and tropical Australian and Austro-Malayan regions are supported, rather than an affinity between the Indo-Asian or Indo-Malaysian and tropical Australian fauna.     

Center of genetic diversity and dissemination pathways in mung bean deduced from seed protein electrophoresis

Summary Seed protein of 581 local strains of mung bean, Vigna radiata (L.) Wilczek, collected from throughout Asia, were analyzed by SDS-polyacrylamide gel electrophoresis. Eight protein types were recognized based on the combination of four albumin bands and three globulin bands. The frequency of each protein type strain showed a clear geographical cline. The pattern of geographical distribution of the protein types reflected the regions of genetic diversity, and two dissemination pathways in mung bean were proposed. The region of genetic diversity in seed protein was western Asia (Afghanistan-Iran-Iraq area). Mung bean may have spread mainly to the east by two routes from India, where the domestication of mung bean is believed to have occurred. One route led to Southeast Asia; strains consisting of a few protein types with prominent protein type 1 were disseminated from India to the Southeast Asian countreis. Thus, the strain composition in Southeast Asia was very simple, with the strains being similar to one another. Another dissemination pathway may have been the route known as the Silk Road. Since protein type 7 and 8 strains could not be found throughout Southeast Asia, it is assumed that these strains spread from western Asia or India to China and Taiwan via the Silk Road, and not by the route from Southeast Asia.