The northward drift of the Indian Plate and its collision with Eurasia have profoundly impacted the evolutionary history of the terrestrial organisms,especially the ones along the Indian Ocean rim.Climbing perches(Ana...The northward drift of the Indian Plate and its collision with Eurasia have profoundly impacted the evolutionary history of the terrestrial organisms,especially the ones along the Indian Ocean rim.Climbing perches(Anabantidae)are primary freshwater fishes showing a disjunct south Asian-African distribution,but with an elusive paleobiogeographic history due to the lack of fossil evidence.Here,based on an updated time-calibrated anabantiform phylogeny integrating a number of relevant fossils,the divergence between Asian and African climbing perches is estimated to have occurred in the middle Eocene(ca.40 Ma,Ma:million years ago),a time when India had already joined with Eurasia.The key fossil lineage is?Eoanabas,the oldest anabantid known so far,from the upper Oligocene of the Tibetan Plateau.Ancestral range reconstructions suggest a Southeast Asian origin in the early Eocene(ca.48 Ma)and subsequent dispersals to Xizang and then India for this group.Thereby we propose their westbound dispersal to Africa via the biotic bridge between India and Africa.If so,climbing perch precursors had probably followed the paleobiogeographical route of snakehead fishes,which have a slightly older divergence between African and Asian taxa.As such,our study echoes some recent molecular analyses in rejecting the previously held‘‘Gondwana continental drift vicariance"or late Mesozoic dispersal scenarios for the climbing perches,but provides a unique biogeographical model to highlight the role of the preuplift Xizang and the docked India in shaping the disjunct distribution of some air-breathing freshwater fishes around the Indian Ocean.展开更多
Disjunct distribution patterns in plant lineages are usually explained according to three hypotheses： vicariance, geodispersal, and long-distance dispersal. The role of these hypotheses is tested in Urgineoideae （Hy...Disjunct distribution patterns in plant lineages are usually explained according to three hypotheses： vicariance, geodispersal, and long-distance dispersal. The role of these hypotheses is tested in Urgineoideae （Hyacinthaceae）, a subfamily disjunctly distributed in Africa, Madagascar, India, and the Mediterranean region. The potential ancestral range, dispersal routes, and factors responsible for the current distribution in Urgineoideae are investigated using divergence time estimations. Urgineoideae originated in Southern Africa approximately 48.9 Mya. Two independent dispersal events in the Western Mediterranean region possibly occurred during Early Oligocene and Miocene （29.9-8.5 Mya） via Eastern and Northwestern Africa. A dispersal from Northwestern Africa to India could have occurred between 16.3 and 7.6 Mya. Vicariance and extinction events occurred approximately 21.6 Mya. Colonization of Madagascar occurred between 30.6 and 16.6 Mya, after a single transoceanic dispersal event from Southern Africa. The current disjunct distributions of Urgineoideae are not satisfactorily explained by Gondwana fragmentation or dispersal via boreotropical forests, due to the younger divergence time estimates. The flattened winged seeds of Urgineoideae could have played an important role in long- distance dispersal by strong winds and big storms, whereas geodispersal could have also occurred from Southern Africa to Asia and the Mediterranean region via the so-called arid and high-altitude corridors.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(XDA20070203,XDB26000000,XDB310403,XDA20070301)the Second Tibetan Plateau Scientific Expedition Program,the National Natural Science Foundation of China(41872006)Youth Innovation Promotion Association,CAS(2017103,2017439)
文摘The northward drift of the Indian Plate and its collision with Eurasia have profoundly impacted the evolutionary history of the terrestrial organisms,especially the ones along the Indian Ocean rim.Climbing perches(Anabantidae)are primary freshwater fishes showing a disjunct south Asian-African distribution,but with an elusive paleobiogeographic history due to the lack of fossil evidence.Here,based on an updated time-calibrated anabantiform phylogeny integrating a number of relevant fossils,the divergence between Asian and African climbing perches is estimated to have occurred in the middle Eocene(ca.40 Ma,Ma:million years ago),a time when India had already joined with Eurasia.The key fossil lineage is?Eoanabas,the oldest anabantid known so far,from the upper Oligocene of the Tibetan Plateau.Ancestral range reconstructions suggest a Southeast Asian origin in the early Eocene(ca.48 Ma)and subsequent dispersals to Xizang and then India for this group.Thereby we propose their westbound dispersal to Africa via the biotic bridge between India and Africa.If so,climbing perch precursors had probably followed the paleobiogeographical route of snakehead fishes,which have a slightly older divergence between African and Asian taxa.As such,our study echoes some recent molecular analyses in rejecting the previously held‘‘Gondwana continental drift vicariance"or late Mesozoic dispersal scenarios for the climbing perches,but provides a unique biogeographical model to highlight the role of the preuplift Xizang and the docked India in shaping the disjunct distribution of some air-breathing freshwater fishes around the Indian Ocean.
基金the Higher Education Commission of Pakistan for providing financial support for the study
文摘Disjunct distribution patterns in plant lineages are usually explained according to three hypotheses： vicariance, geodispersal, and long-distance dispersal. The role of these hypotheses is tested in Urgineoideae （Hyacinthaceae）, a subfamily disjunctly distributed in Africa, Madagascar, India, and the Mediterranean region. The potential ancestral range, dispersal routes, and factors responsible for the current distribution in Urgineoideae are investigated using divergence time estimations. Urgineoideae originated in Southern Africa approximately 48.9 Mya. Two independent dispersal events in the Western Mediterranean region possibly occurred during Early Oligocene and Miocene （29.9-8.5 Mya） via Eastern and Northwestern Africa. A dispersal from Northwestern Africa to India could have occurred between 16.3 and 7.6 Mya. Vicariance and extinction events occurred approximately 21.6 Mya. Colonization of Madagascar occurred between 30.6 and 16.6 Mya, after a single transoceanic dispersal event from Southern Africa. The current disjunct distributions of Urgineoideae are not satisfactorily explained by Gondwana fragmentation or dispersal via boreotropical forests, due to the younger divergence time estimates. The flattened winged seeds of Urgineoideae could have played an important role in long- distance dispersal by strong winds and big storms, whereas geodispersal could have also occurred from Southern Africa to Asia and the Mediterranean region via the so-called arid and high-altitude corridors.
