Abstract
Hybridization plays a significant role in biological evolution.However,it is not clear whether ecological contingency differentially influences likelihood of hybridization,particularly at ecological margins where parental species may exhibit reduced fitnesses.Moreover,it is unknown whether future ecosystem change will increase the prevalence of hybridization.Ficus heterostyla and F.squamosa are closely related species co-distributed from southern Thailand to southwest China where hybridization,yielding viable seeds,has been documented.As a robust test of ecological factors driving hybridization,we investigated spatial hybridization signatures based on nuclear microsatellites from extensive population sampling across a widespread contact range.Both species showed high population differentiation and strong patterns of isolation by distance.Admixture estimates exposed asymmetric interspecific gene flow.Signatures of hybridization increase significantly towards higher latitude zones,peaking at the northern climatic margins.Geographic variation in reproductive phenology combined with ecologically chal-lenging marginal habitats may promote this phenomenon.Our work is a first systematic evaluation of such patterns in a comprehensive,latitudinally-based clinal context,and indicates that tendency to hybridize appears strongly influenced by environmental conditions.Moreover,that future climate change scenarios will likely alter and possibly augment cases of hybridization at ecosystem scales.
基金项目
国家自然科学基金(31800313)
国家自然科学基金(32261123001)
Applied Basic Research Foundation of Yunnan Province(202301AT070378)
Applied Basic Research Foundation of Yunnan Province(2019FB034)
the"Light of West China"Program of the Chinese Academic of Sciences()
Guangzhou Collaborative Innovation Center on Sciencetech of Ecology and Landscape()
国家科技期刊平台
NSTL
万方数据