%0 Journal Article
%T Evolutionary divergence times in the Annonaceae: evidence of a late Miocene origin of Pseuduvaria in Sundaland with subsequent diversification in New Guinea
%A Yvonne CF Su
%A Richard MK Saunders
%J BMC Evolutionary Biology
%D 2009
%I BioMed Central
%R 10.1186/1471-2148-9-153
%X The divergence times of the main clades within the Annonaceae were found to deviate slightly from previous estimates that used different calibration points and dating methods. In particular, our estimate for the SBC crown (55.2-26.9 Mya) is much younger than previous estimates (62.5-53.1 ¡À 3.6 Mya and ca. 58.76 Mya). Early diversification of Pseuduvaria was estimated to have occurred 15-8 Mya, possibly associated with the 'mid-Miocene climatic optimum.' Pseuduvaria is inferred to have originated in Sundaland in the late Miocene, ca. 8 Mya; subsequent migration events were predominantly eastwards towards New Guinea and Australia, although several migratory reversals are also postulated. Speciation of Pseuduvaria within New Guinea may have occurred after ca. 6.5 Mya, possibly coinciding with the formation of the Central Range orogeny from ca. 8 Mya.Our divergence time estimates within the Annonaceae are likely to be more precise as we used a UCLD clock model and calibrated the phylogeny using new fossil evidence. Pseuduvaria is shown to have dispersed from Sundaland after the late Miocene. The present-day paleotropical distribution of Pseuduvaria may have been achieved by long-distance dispersal, and speciation events might be explained by global climatic oscillations, sea level fluctuations, and tectonic activity.The Annonaceae are a large pantropical family of flowering plants, consisting of ca. 135 genera and ca. 2,500 species in predominantly tropical and subtropical lowland forests [1]. The phylogeny of the family has previously been reconstructed based on morphological [2-4] and molecular data [5-7]. Four main clades are consistently recognised in the molecular analyses: two of these clades (consisting of Anaxagorea and the small 'ambavioid' clade) form a heterogeneous basal grade, basal to two large clades known as the 'long branch clade' (LBC) and 'short branch clade' (SBC) to reflect differing rates of nucleotide substitutions [7,8].Evolutionary divergence ti
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