摘要
Understanding how many species exist and the processes by which they form remains a central topic of ecological and evolutionary biology,but represents a special challenge within microbial groups.The lichen-forming fungi represent one of the best examples in which species evolution and diversity create patterns of high phenotypic plasticity coupled with wide geographic distributions.We sampled the lichen-forming species Tephromela atra and related species at a world-wide scale to reconstruct a phylogenetic hypothesis using three nuclear markers.Samples were also studied for morphological and chemical traits to assess how well the phenotypic relationships with species,previously segregated from T.atra,agrees with molecular data.We used a genealogical concordance approach and identified 15 monophyletic clades,which may represent independent lineages.By combining morphological and chemical characters,ecological preferences and geographic origin we distinguish six different species.Although subtle phenotypical traits are frequently used for describing previously cryptic species in fungi,the continuum of variability found in morphology and chemical patterns in T.atra prevents the description of new taxa with characteristic traits.We observed that phenotypic characters arise in parallel at local or regional scale but are not correlated with genetic isolation.Therefore,they are insufficient for characterizing species with broad geographic ranges within T.atra.
基金
LM,MG and TS are grateful to the Austrian Science Foundation for financial support(LM for FWF Herta-Firnberg Project T481-B20,TS for FWF P25237)
SPO is supported by the grant CTM2012-38222-C02-02 from the Spanish Ministry of Economy and Competitiveness.Program.
