Name: | Description: | Size: | Format: | |
---|---|---|---|---|
676.74 KB | Adobe PDF |
Advisor(s)
Abstract(s)
Studying the biogeography and the phylogeography of the endemic Macaronesian red
Festuca species (Loliinae, Poaceae) is of prime interest in understanding the speciation
and colonization patterns of recently evolved groups in oceanic archipelagos. Coales cence-based analyses of plastid trnLF sequences were employed to estimate evolutionary
parameters and to test different species-history scenarios that model the pattern of
species divergence. Bayesian IM estimates of species divergence times suggested that
ancestral lineages of diploid Macaronesian and Iberian red fescues could have diverged
between 1.2 and 1.57 Ma. When empirical data were compared to coalescence-based
simulated distributions of discordance and p-distance statistics, two species-history
models were chosen in which the first branching lineage derived in Canarian Festuca
agustinii. Its sister lineage could have involved a recent polytomy leading to the
Madeiran Festuca jubata, the Azorean Festuca francoi + Festuca petraea and the
continental Festuca rivularis lineages (Canarian model) or the sequential branching of
lineages leading to F. jubata and finally to the sister clades of F. rivularis and
F. francoi + F. petraea (Sequential model). Nested clade phylogeographic analysis
(NCPA) and a first adapted host–parasite co-evolutionary ParaFit method were used to
detect the phylogeographic signal. NCPA inferred long-distance colonizations for the
entire diploid red Festuca complex, but allopatric-fragmentation and isolation by-distance (IBD) patterns were inferred within archipelagos. In addition, the ParaFit
method suggested a generalized pattern of a stepping-stone model at all hierarchical
levels. Maximum-likelihood-based dispersal-extinction-cladogenesis (DEC) models were
superimposed on the Sequential model species tree. The three-independent-colonization
(3IC) model was the best supported biogeographic scenario, concurring with previous
analysis based on multilocus AFLP data.
Description
Keywords
Biogeography Coalescence Oceanic island plants Phylogeography Plastid trnLF gene Species divergence time . Faculdade de Ciências da Vida
Citation
Díaz‐Pérez, A. J., Sequeira, M., Santos‐Guerra, A., & Catalán, P. (2012). Divergence and biogeography of the recently evolved Macaronesian red Festuca (Gramineae) species inferred from coalescence‐based analyses. Molecular Ecology, 21(7), 1702-1726. https://doi.org/10.1111/j.1365-294X.2012.05495.x
Publisher
Wiley