Symposium proposal | |
Organizer: | Che Jing (Kunming Institute of Zoology, Chinese Academy of Sciences ) |
Co-organizer: | Jinxian Liu (Institute of Oceanology, Chinese Academy of Sciences) |
Asia exhibits remarkable topographic diversity, including numerous mountain systems and islands. This symposium focuses on biogeography in Asia across spatial and temporal scales. Both historical notes and novel approaches are welcomed. We aim to understand those drivers in forming high species richness and endemism in this region and promote its conservation accordingly. |
S8-1
Phylogeographic history and genomic architecture of rapid parallel adaptation to fresh water in a wild fish
Jin-Xian Liu1, Shao-Bing Zong1, Yu-Long Li1
1Institute of Oceanology, Chinese Academy of Sciences
Two ecotypes, the anadromous form and the freshwater resident form exist in the Japanese grenadier anchovy (Coilia nasus). The phylogeographic history has remained controversial largely due to lack of comprehensive genetic evidence. Rapid adaptation to novel environments may drive changes in genomic regions through natural selection. However, the genetic architecture underlying these adaptive changes is still poorly understood. Using phylogeographic and population genomic approaches, we investigated phyogeographic history and the genomic architecture that underlay rapid parallel adaptation of Coilia nasus to fresh water. Substantial and significant phylogeographic divergences were revealed between the anadromous population and the freshwater resident populations from the middle of the Yangtze River, which diverged from each other around 10,000 years ago, consistent with the last glaciation. However, no phylogeographic differentiation was detected between the anadromous population and the freshwater resident populations from the lower reaches of the Yangtze River. Linkage disequilibrium network analysis and population genetic analyses revealed two putative large chromosome inversions on LG6 and LG22, which were enriched for outlier loci and exhibited parallel association with freshwater adaptation of the freshwater resident form in the lower reaches of the Yangtze River. Drastic frequency shifts and elevated genetic differentiation were observed for the two chromosome inversions among populations, suggesting that both inversions would undergo divergent selection between anadromous and resident ecotypes. Enrichment analysis of genes within chromosome inversions showed significant enrichment of genes involved in metabolic process, immunoregulation, growth, maturation, osmoregulation, etc., which probably underlay differences in morphology, physiology and behavior between the anadromous and freshwater resident forms. The availability of beneficial standing variation, large optimum shift between marine and freshwater habitats, and high efficiency of selection with large population size could lead to the observed rapid parallel adaptive genomic change. We propose that chromosomal inversions might have played an important role during the evolution of rapid parallel ecological divergence in the face of environmental heterogeneity in C. nasus. Our study provides insights into the genomic basis of rapid adaptation of complex traits in novel habitats and highlights the importance of structural genomic variants in analyses of ecological adaptation.
S8-2
Cenozoic climate changes regulate the northern temperate woody species diversity-Juglandaceae as a case study
Yaowu Xing1, Qiuyue Zhang1,2,3, Richard H. Ree5, Nicolas Salamin3, Daniele Silvestro2,4
1Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, 666303 Menglun, China
2Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
3Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland
4Swiss Institute of Bioinformatics, Quartier Sorge, 1015 Lausanne, Switzerland
5Life Sciences Section, Negaunee Integrative Research Center, The Field Museum, 60605 Chicago, USA
2Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
3Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland
4Swiss Institute of Bioinformatics, Quartier Sorge, 1015 Lausanne, Switzerland
5Life Sciences Section, Negaunee Integrative Research Center, The Field Museum, 60605 Chicago, USA
Temperate woody plants in the Northern Hemisphere display a consistent, long recognized, diversity pattern with high species richness in East Asia and North America and significantly lower diversity in Europe. Yet, the origin and evolution of such a pattern remain debated. Here, we quantify the roles of dispersal, niche evolution, and extinction in shaping temperate woody plant diversity within the walnut family, Juglandaceae. We use a cohesive analytical framework by integrating evidence from molecular, morphological, fossil, and (paleo)environmental data to infer the biogeographic history and niche evolution of Juglandaceae. Our results strongly support a Boreotropical origin of the family with the temperate subfamily Juglandoideae showing rapid niche evolution to frost tolerance when the global climate shifted to ice-house climate from the Oligocene. Temperate-adapted lineages diversified and expanded their geographical range to high latitudes especially in Europe and Asia during the Miocene. A southward range contraction a 27 t high latitudes and high levels of extinction in Europe driven by global cooling later lead to the regional disparity in tree species diversity. The tropical subfamily Engelhardioideae showed temperature conservatism while adapting to increased humidity and continuously moving into the tropical zone with low diversity since the middle Eocene due to high competition in the tropical zone. In addition, we show the North Atlantic land bridge and Europe played more critical roles than previously thought in linking East Asia and North American floras. The evolution of Juglandaceae showcases the complex interplay among climate change, niche evolution, dispersal, and extinction that shaped the modern disjunct pattern of species richness in temperate woody plants.
S8-3
An iconic model island archipelago study system comes of age in the era of genomics
Rafe M. Brown1
1University of Kansas Biodiversity Institute
Because of their fragmented, partitioned, and sometimes hierarchically-arranged geography, island archipelagos offer biogeographers unique opportunities for testing hypotheses of common mechanisms of evolutionary diversification. Hypotheses of common mechanisms, or shared drivers of diversification, are of particular interest to conceptual studies of the generation of biodiversity. This is because of the compelling possibility that numerous, unrelated and biologically disparate lineages may have experienced similar or, even, virtually identical evolutionary histories (timing and pattern of divergences), simply as a function of their distribution across the same, archipelagic, geographical template. In this presentation I will briefly review a quarter-century research program involving evolutionary processes of diversification in endemic terrestrial vertebrates of an iconic, model island archipelago: the Philippines. Numerous comparative studies of codistributed, entirely endemic, clades of amphibians, mammals, birds, and reptiles have led to the formulation of the Philippine Pleistocene Aggregate Island Complex model of diversification, also known as the “PAIC Paradigm.” This simple, elegant, hypothesis-testing framework predicts the repeated partitioning of Philippine vertebrate clades into five major geographical areas of endemism and predicts that sea level vicariance within these faunal regions may have led to the extraordinary terrestrial vertebrate microendemism that we see today. Numerous phylogenetic and population genetic exceptions to these predictions have been identified in various organisms, but the power of new genomic resources now provides extraordinarily detailed insight into these patterns, while accommodating uncertainty in statistical inference of underlying evolutionary processes. In this presentation, I will highlight two recent studies of Philippine frog clades involving 14,000-locus genomic datasets and powerful speciation delimitation statistics, both of which confirm and expand predictions from PAIC Paradigm, ultimately augmenting this now classic model island archipelago study system, via inference of speciation in the presence of gene flow, admixture, and reticulation during evolutionary radiation.
S8-4
Evolutionary and demographic history of Philippine native pigs and the perplexing mtDNA variation in Philippine wild pigs
John King N. Layos1,2, Cyrill John P. Godinez1,3, Yoshio Yamamoto1, Hideyuki Mannen4, Lawrence M. Liao5, Masahide Nishibori1
1Laboratory of Animal Genetics, Graduate School of Integrated Sciences for Life, Hiroshima University, Kagamiyama 1-4-4, Higashi-Hiroshima 739-8528, Japan
2College of Agriculture and Forestry, Capiz State University, Burias Campus, Mambusao, Capiz 5807, Philippines
3Department of Animal Science, Visayas State University, Visca, Baybay City, Leyte 6521, Philippines
4Laboratory of Animal Breeding and Genetics, Graduate School of Agricultural Science, Kobe University, Rokkodai 1-1, Nada, Kobe 657-8501, Japan
5Laboratory of Aquatic Ecology, Graduate School of Integrated Sciences for Life, Hiroshima University, Kagamiyama 1-4-4, Higashi-Hiroshima 739-8528, Japan
2College of Agriculture and Forestry, Capiz State University, Burias Campus, Mambusao, Capiz 5807, Philippines
3Department of Animal Science, Visayas State University, Visca, Baybay City, Leyte 6521, Philippines
4Laboratory of Animal Breeding and Genetics, Graduate School of Agricultural Science, Kobe University, Rokkodai 1-1, Nada, Kobe 657-8501, Japan
5Laboratory of Aquatic Ecology, Graduate School of Integrated Sciences for Life, Hiroshima University, Kagamiyama 1-4-4, Higashi-Hiroshima 739-8528, Japan
The Philippines is an archipelago of 7,641 islands situated in Island Southeast Asia at the crossroads of past human migrations in the Asia-Pacific region. It was believed to have never been connected to the Asian continent, even during the severe Quaternary sea-level drops. As a result, the history of pig dispersal in the Philippines remains controversial due to the limited molecular studies and the absence of archaeological assemblages that exhibit signs of pig domestication. This study provides the first comprehensive screening of the mitochondrial DNA of Philippine native pigs (n=175) and Philippine wild pigs (n=9) to resolve their earlier dispersal history by conducting phylogenomic analysis altogether with the domestic pig and wild boars corresponding roughly to their geographic origin. Results revealed a demographic signal of pig ancestry exhibiting a close genetic affiliation from mainland Southeast Asia and Northeast Asia Regions which corroborates a gene flow that might have arisen through human migration and trade. Here, we proposed two possible dispersal routes. One is through Northeast Asia paralleled with the Neolithic expansion in Island Southeast Asia and Oceania, and the other is through mainland Southeast Asia, which may have traversed through the Sundaic Region to Palawan and the Sulu Archipelago. Despite geographical barriers to migration, numerous genetic lineages have persisted on various Philippine islands and even warrant the recognition of a Philippine Lanyu sub-clade. The prehistoric population dynamics predate a demographic expansion coinciding with the interglacial periods of the Pleistocene as the Southern regions to be the probable origin of spread correlating the northwest gene flow of the Southern Negritos to the Philippines that entered Mindanao via the Sulu Archipelago. The intriguing signal of disparity detected among the maternal pattern, morphology, and distribution range of the numerous Philippine endemic wild pigs opens a new challenging approach in shedding the complexities between these animals.
S8-5
Herpetological phylogeographic analyses support a Miocene focal point of Himalayan uplift and biological diversification
Wei Xu1
1Kunming Institute of Zoology, Chinese Academy of Sciences
The Himalaya are among the youngest and highest mountains in the world, but the exact timing of their uplift and origins of their biodiversity are still in debate. The Himalayan region is a relatively small area but with exceptional diversity and endemism. One common hypothesis to explain the rich montane diversity is uplift-driven diversification–that orogeny creates conditions favoring rapid in situ speciation of resident lineages. We test this hypothesis in the Himalayan region using amphibians and reptiles, two environmental sensitive vertebrate groups. In addition, analysis of diversification of the herpetofauna provides an independent source of information to test competing geological hypotheses of Himalayan orogenesis. We conclude that the origins of the Himalayan herpetofauna date to the early Paleocene, but that diversification of most groups was concentrated in the Miocene. There was an increase in both rates and modes of diversification during the early to middle Miocene, together with regional interchange (dispersal) between the Himalaya and adjacent regions. Our analyses support a recently proposed stepwise geological model of Himalayan uplift beginning in the Paleocene, with a subsequent rapid increase of uplifting during the Miocene, finally give rise to the intensification of the modern South Asia Monsoon.