Eden in the East: The Drowned Continent of Southeast Asia

Eden in the East: The Drowned Continent of Southeast Asia. Stephen Oppenheimer. London: Orion (Weidenfeld and Nicolson), 1998.560 pp.     

Nonconcordant evolutionary history of maternal and paternal lineages in Adriatic sturgeon

Although analyses of intraspecific variability are an important prerequisite for species identification assays, only a few studies have focused on population genetics and historical biogeography of sturgeon species. Here we present the first study on genetic variability of the last remaining Adriatic sturgeon, Acipenser naccarii, derived from mitochondrial and nuclear DNA. Our mitochondrial DNA analyses arranged individuals into three distinguished mitochondrial DNA haplogroups (Po1, Po2 and Buna). Two haplogroups (Po1 and Buna) were correlated to geographical distribution, whereas the third (Po2) was not. It was, however, very closely related to one lineage of its Ponto-Caspian sister species, A. gueldenstaedtii. The distribution of nuclear markers (microsatellites and amplified fragment length polymorphism) was strongly correlated to geographical distribution. An assignment test based on nuclear data placed no specimen of A. naccarii to A. gueldenstaedtii and vice versa. Therefore, the presence of gueldenstaedtii-like haplotypes within the Po population is either the result of a postglacial introgression or an ancestral polymorphism and does not indicate a hybrid population. The most valuable tool for forensic species identification purposes is one diagnostic deletion separating all A. naccarii from A. gueldenstaedtii. As both A. naccarii populations are genetically differentiated, stocking of sturgeon from the Po River in Italy into waters of the Buna River would jeopardize the genetic differences between both populations and should thus be avoided.     

mtDNA and language support a common origin of Micronesians and Polynesians in Island Southeast Asia

The origins and relationships among Micronesians, Polynesians, and Melanesians were investigated. Five different mtDNA region V length polymorphisms from 873 individuals representing 24 Oceanic and Asian populations were analyzed. The frequency cline of a common deletion and the distributions of a rare expanded length polymorphism support the origin of both Micronesians and Polynesians in Island Southeast Asia. Genetic, linguistic, and geographic distances were compared to assess the relative importance of isolation and gene flow during the prehistory of 19 Austronesian-speaking populations subdivided into five potential spheres of interaction. We observed significant correlations (P < 0.05) between genetic and linguistic distances in four of five comparisons. These data indicate extensive gene flow throughout much of Micronesia, but substantial isolation in other Pacific regions. Although recent advancements in our understanding of intentional voyaging within Remote Oceania have challenged the existence of the “myth of the primitive isolate,” we caution against the adoption of panmictic alternatives. Am J Phys Anthropol 105:109–119, 1998. © 1998 Wiley-Liss, Inc.     

Mitochondrial genomes from modern and ancient Turano-Mongolian cattle reveal an ancient diversity of taurine maternal lineages in East Asia

Turano-Mongolian cattle are a group of taurine cattle from Northern and Eastern Asia with distinct morphological traits, which are known for their ability to tolerate harsh environments, such as the Asian steppe and the Tibetan plateau. Through the analysis of 170 mitogenomes from ten modern breeds, two sub-lineages within T3 (T3₁₁₉ and T3₀₅₅) were identified as specific of Turano-Mongolian cattle. These two T3 sub-lineages, together with the previously identified T4, were also present in six Neolithic samples, dated to ~3900 years BP, which might represent the earliest domestic taurine stocks from Southwest Asia. The rare haplogroup Q, found in three Tibetan cattle, testifies for the legacy of ancient migrations from Southwest Asia and suggests that the isolated Tibetan Plateau preserved unique prehistoric genetic resources. These findings confirm the geographic substructure of Turano-Mongolian cattle breeds, which have been shaped by ancient migrations and geographic barriers.Subject terms: Animal migration, Haplotypes, Phylogenetics     

Reconstruction of major maternal and paternal lineages of the Cape Muslim population

The earliest Cape Muslims were brought to the Cape (Cape Town - South Africa) from Africa and Asia from 1652 to 1834. They were part of an involuntary migration of slaves, political prisoners and convicts, and they contributed to the ethnic diversity of the present Cape Muslim population of South Africa. The history of the Cape Muslims has been well documented and researched however no in-depth genetic studies have been undertaken. The aim of the present study was to determine the respective African, Asian and European contributions to the mtDNA (maternal) and Y-chromosomal (paternal) gene pool of the Cape Muslim population, by analyzing DNA samples of 100 unrelated Muslim males born in the Cape Metropolitan area. A panel of six mtDNA and eight Y-chromosome SNP markers were screened using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). Overall admixture estimates for the maternal line indicated Asian (0.4168) and African mtDNA (0.4005) as the main contributors. The admixture estimates for the paternal line, however, showed a predominance of the Asian contribution (0.7852). The findings are in accordance with historical data on the origins of the early Cape Muslims.     

Gondwanan survivor lineages and the high-risk biogeography of Anthropocene Southeast Asia

The Southeast Asian rainforest region is extremely complex and biodiverse. Fossils have shown that paleo-Antarctic rainforest lineages (PARLs) now extant in Asia tracked the ever-wet conditions needed to survive and diversify through deep time. However, the threat of future climate change to the remaining rainforest and PARLs in Southeast Asia has yet to be evaluated to set conservation priorities. We first quantified the woody-genus floristic relationships of Southeast Asian Island Groups by vetting and analyzing recent compilations of bioregional species data. We then evaluated the contributions to community assembly of woody fossil lineages and Island Group relationships to environmental gradients. To better understand climatic constraints of fossil lineage distributions and forecast distributions under projected future climate, we used exemplar living woody PARLs, including two angiosperms and two gymnosperms. Generalized linear models were used to project potential distributions under future climate pathways that assume no reduction in carbon dioxide emissions. The floristic analyses highlighted strong similarities among Island Groups in the ever-wet forest areas of Malesia, where PARLs are often concentrated. Ordination outliers represented more seasonal locations. Species distribution models showed that potential future distributions of ancient lineages are constrained by increasing rainfall seasonality and higher seasonal temperatures, with significant differences among exemplar genera. Notably, potential distributions often mapped onto de facto inaccessible areas, where forest clearing and the ubiquitous marine dispersal barriers that characterize the region will drastically inhibit potential relocation. These realities gravely threaten paleo-conservation values and contemporary rainforest community assembly processes in Southeast Asia.     

Violence,solace, and ritual: A case study from Island Southeast Asia

Most headhunting traditions in island Southeast Asia link ritual violence to grief and mourning. Some of the more persuasive analyses of these practices pivot on notions of rage and catharsis, arguing that turbulent emotions motivate persons to take up cleansing acts of violence. This paper seeks a more complex understanding of how ritual may connect bereavement and violence through a look at case materials from highland Sulawesi (Indonesia). Ritual practices there suggestthat the resolution of communal mourning is more significant than personal catharsis in motivating violence; that individual affect is refigured collectively as political affect; and that varied discursive forms, such as vows, songs, and noise mediate the ways in which people put grief behind them and resume their lives. Indeed, such discursive forms appear to be generative sites for violence and solace.     

Hybrid origin and differentiation of two tetraploid Achillea species in East Asia: molecular, morphological and ecogeographical evidence

Achillea (Asteraceae-Anthemideae) offers classical models for speciation by hybridization and polyploidy. Here, we test the suspected allotetraploid origin of two species, Achillea alpina and Achillea wilsoniana between phylogenetically distinct lineages in East Asia. A total of 421 AFLP bands from 169 individuals and 19 populations of five 2x- and two 4x-species were obtained. The data set was analysed with a newly developed model that accounts for polyploidy and assumes lack of recombination between the parental chromosome sets (i.e. disomic inheritance). A. alpina and A. wilsoniana then appear to be allotetraploids between Achillea acuminata-2x (sect. Ptarmica) and Achillea asiatica-2x (sect. Achillea). The two 4x-species share 44% and 48% of their AFLP bands with A. acuminata-2x, and 39% and 38% with A. asiatica-2x, respectively. Eight plastid haplotypes (A-H) were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses. A. alpina-4x and A. wilsoniana-4x share haplotype F only with A. asiatica-2x. This is consistent with the hybrid origin(s) involving the latter as the maternal ancestor. This result corroborates our previous DNA sequence data, where A. alpina-4x and A. wilsoniana-4x are also placed close to A. asiatica-2x. Morphology, ecology, and amplified fragment length polymorphism (AFLP) profiles of the two 2x-species are distinct, whereas the two 4x-species, grouped as A. alpina aggregate, form a nearly continuous link between them. Considering all evidence, this 4x-aggregate is regarded as the product of a hybridization between genetically distant 2x-ancestors limited to China and adjacent areas: one A. acuminata-like, and the other A. asiatica-like. The allopolyploid A. alpina agg. exhibits considerable morphological variation and ecological flexibility, and has expanded throughout eastern Asia and to northern North America, far beyond the ranges of their presumed 2x-ancestors.     

A predominantly indigenous paternal heritage for the Austronesian-speaking peoples of insular Southeast Asia and Oceania

Modern humans reached Southeast Asia and Oceania in one of the first dispersals out of Africa. The resulting temporal overlap of modern and archaic humans-and the apparent morphological continuity between them-has led to claims of gene flow between Homo sapiens and H. erectus. Much more recently, an agricultural technology from mainland Asia spread into the region, possibly in association with Austronesian languages. Using detailed genealogical study of Y chromosome variation, we show that the majority of current Austronesian speakers trace their paternal heritage to Pleistocene settlers in the region, as opposed to more-recent agricultural immigrants. A fraction of the paternal heritage, however, appears to be associated with more-recent immigrants from northern populations. We also show that the northern Neolithic component is very unevenly dispersed through the region, with a higher contribution in Southeast Asia and a nearly complete absence in Melanesia. Contrary to claims of gene flow (under regional continuity) between H. erectus and H. sapiens, we found no ancestral Y chromosome lineages in a set of 1,209 samples. The finding excludes the possibility that early hominids contributed significantly to the paternal heritage of the region.     

Molecular phylogeny of hipposiderid bats from Southeast Asia and evidence of cryptic diversity

Old World leaf-nosed bats (Hipposideridae) are among the most widespread and ecologically diverse groups of insectivorous bats in the Old World tropics. However, phylogenetic relationships in Hipposideridae are poorly resolved at both the generic and species levels, and deep genetic divergence within several Southeast Asian species suggests that current taxonomy underestimates hipposiderid diversity in this region. We used mitochondrial and nuclear sequence data to conduct the first extensive molecular phylogenetic analysis of Southeast Asian hipposiderid bats. Inclusion of multiple samples per taxon allowed testing for evidence of evolutionarily distinct lineages within taxa currently defined as single species. In contrast to earlier phylogenies based on morphometrics, molecular data support monophyly of Hipposideros, but are ambiguous regarding the monophyly of Hipposideridae. With a few exceptions, molecular data also support currently recognized species groups classified by qualitative morphological characters. Widespread paraphyly and polyphyly within many currently recognized species of Hipposideros indicates that evolutionary diversity in the genus is underrepresented by current nomenclature. Comparison of available morphological and echolocation data suggest that both geographic isolation and ecological selection have contributed to the diversification of Southeast Asian hipposiderid bats.