Patterns of speciation are similar across mountainous and lowland regions for a Neotropical plant radiation (Costaceae: Costus)
Patterns of speciation are similar across mountainous and lowland regions for a Neotropical plant radiation (Costaceae: Costus)
复制标题
DOI：
10.1111/evo.14108
复制
发表时间：
2020-05
期刊：
影响因子：
--
通讯作者：
Oscar M. Vargas;Brittany Goldston;Dena L. Grossenbacher;Kathleen M. Kay
中科院分区：
文献类型：
--
作者：
Oscar M. Vargas;Brittany Goldston;Dena L. Grossenbacher;Kathleen M. Kay
热带山区的物种丰富度和特有性被认为是造成纬度多样性梯度的主要因素。然而，山区物种形成的基本过程在很大程度上未经检验。陡峭的生态地理梯度和地理隔离的人口地形特征的流行，预计将促进在山区的物种形成。我们评估这些过程中的一个物种丰富的新热带属的林下草本植物，范围从低地到山地森林，在地形复杂的地区有较高的物种丰富度。我们问是否气候生态位的分歧，地理隔离，和授粉的变化不同的山区影响和低地亚马逊姐妹对推断从756个基因的同源性。新热带区Costus的祖先分歧在中美洲的一个时期的山区形成在过去的3我与后来的殖民亚马逊河流域。虽然气候差异、地理隔离和授粉转移普遍存在，但这些因素在受山脉影响的姐妹对和亚马逊姐妹对之间没有区别。尽管较高的气候生态位和物种多样性在山区，物种形成模式在Costus出现相似的跨区域。因此，热带山区更丰富的物种可能反映了殖民历史、多样化率或快速进化植物生命形式的流行程度的差异，而不是物种形成模式的差异。
High species richness and endemism in tropical mountains are recognized as major contributors to the latitudinal diversity gradient. The processes underlying mountain speciation, however, are largely untested. The prevalence of steep ecogeographic gradients and the geographic isolation of populations by topographic features are predicted to promote speciation in mountains. We evaluate these processes in a species-rich Neotropical genus of understory herbs that range from the lowlands to montane forests and have higher species richness in topographically complex regions. We ask whether climatic niche divergence, geographic isolation, and pollination shifts differ between mountain-influenced and lowland Amazonian sister pairs inferred from a 756-gene phylogeny. Neotropical Costus ancestors diverged in Central America during a period of mountain formation in the last 3 My with later colonization of Amazonia. Although climatic divergence, geographic isolation, and pollination shifts are prevalent in general, these factors don’t differ between mountain-influenced and Amazonian sister pairs. Despite higher climatic niche and species diversity in the mountains, speciation modes in Costus appear similar across regions. Thus, greater species richness in tropical mountains may reflect differences in colonization history, diversification rates, or the prevalence of rapidly evolving plant life forms, rather than differences in speciation mode.