臺灣產黑蒙西氏小雨蛙(Microhyla heymonsi)族群遺傳結構與親緣地理學研究

臺灣在地形結構上相當多樣且與鄰近地區的地理關係相當密切，因此臺灣島上生物的族群結構易受到地形及環境氣候而影響。兩棲類動物一般被認為是遷移能力較差的脊椎動物類群，更容易受到地形及環境變遷影響其族群結構。黑蒙西氏小雨蛙(Microhyla heymonsi)分布於南亞及東南亞地區，在臺灣的分布則是中、南部的中低海拔地區，適合以此為材料來探討臺灣高度的地形歧異度以及歷史上豐富的地質事件，是否會對黑蒙西氏小雨蛙的族群遺傳結果造成影響。本研究利用粒線體中的cytochrome oxidase I (COI)部份序列來進行族群遺傳結構的探討。結果顯示臺灣黑蒙西氏小雨蛙族群可分成兩個主要的系群，分別對應中央山脈以東及以西的族群，顯示中央山脈的確是會造成東、西部族群因地理隔離的效應而產生遺傳分化的情形。以中性演化理論檢測、Mismatch distribution、以及貝氏天際線點圖的結果顯示，在更新世時期，臺灣黑蒙西氏小雨蛙族群經過了快速擴張的事件，提供了一個生活在亞熱帶及熱帶地區的生物，受到更新世氣候變遷影響的例子。

In this study, we used Microhyla heymonsi (Anura: Microhylidae), a low to mid-altitude distributed narrow-mouth frog in Taiwan, to investigate the pattern of phylogeography based on its mitochondrial cytochrome oxidase I (COI) gene. The results of its phylogenetic tree indicated two major haplotype clades in Taiwan. The variation in population genetics of these two clades corresponded to the Central Mountain Range’s eastern and western geographical features, respectively. The Central Mountain Range is a geographic barrier that runs from the north to the south of Taiwan Island and disrupts the gene flow between eastern and western populations. Both major clades showed a significant isolation by distance effect. Historical population demography analyzed using neutrality tests, mismatch distribution, and Bayesian skyline plot analyses showed that populations of M. heymonsi in Taiwan underwent an expansion event during the Pleistocene Epoch.