Slowing taxon cycle can explain biodiversity patterns on islands:Insights into the biogeography of the tropical South Pacific from molecular data  

作　　者：Gunnar Keppel Francis J.Nge Thomas Ibanez 

机构地区：[1]UniSA STEM and Future Industries Institute,University of South Australia,GPO Box 2471,Adelaide,5001,SA,Australia [2]AMAP,Universite de Montpellier,CIRAD,CNRS,INRAE,IRD,Montpellier,France [3]Dynadiv,DIADE,IRDlnstitut de Recherche pour le Developpement,Avenue Agropolis BP 64501,Montpellier,34394,France [4]School of Biological Sciences,Faculty of Science,Adelaide 5000,SA,Australia

出　　处：《Journal of Systematics and Evolution》2024年第2期201-214,共14页植物分类学报（英文版）

摘　　要：Islands in the tropical Pacific Ocean are renowned for high biodiversity and endemism despite having relatively small landmasses.However,our knowledge of how this biodiversity is formed remains limited.The taxon cycle,where well-dispersed,earlier colonizers become displaced from coastal to inland habitats by new waves of colonizers,producing isolated,range-restricted species,has been proposed to explain current biodiversity patterns.Here,we integrate the outcomes of phylogenetic studies in the region to investigate the sources,age,number of colonizations,and diversification of 16 archipelagos in the tropical and subtropical South Pacific.We then evaluate whether the results support the taxon cycle as a plausible mechanism for these observations.We find that most species in the Pacific arrived less than 5 Mya from geographically close sources,suggesting that colonization by new taxa is a frequent and ongoing process.Therefore,our findings are broadly consistent with the theory of the Taxon Cycle,which posits that ongoing colonization results in the gradual displacement of established lineages.Only the oldest archipelagos,New Caledonia and Fiji,do not conform to this trend,having proportionally less recent colonization events,suggesting that the taxon cycle may slow on older islands.This conclusion is further validated by New Caledonia having lower diversification rate estimates than younger islands.We found that diversification rates across archipelagos are negatively correlated with area and age.Therefore,a taxon cycle that slows with island age appears to be a suitable concept for understanding the dynamic nature and biodiversity patterns of the Pacific Islands.

关 键 词：COLONIZATION diversification island biogeography Pacific PHYLOGEOGRAPHY taxon cycle 

分 类 号：Q94[生物学—植物学]