Pleistocene and pre-Pleistocene Begonia speciation in Africa

Population history and gene dispersal inferred from spatial genetic structure of a Central African timber tree, Distemonanthus benthamianus (Caesalpinioideae)

“…Forest fragmentation, for example, during cold and dry periods of the Last Maximum Glaciation at the end of the Pleistocene (Maley, 1996;Plana et al, 2004), likely caused the decline of D. benthamianus, which would have survived only in isolated populations, each subject to drift. With the return of more favourable conditions, the species then recolonized the whole region from these relict populations.…”

The Origin of Diversity in Begonia: Genome Dynamism, Population Processes and Phylogenetic Patterns

“…The distribution of Begonia diversity is uneven throughout tropical regions, with the greatest diversity in America and Asia (>600 species each), whilst being relatively species poor in Africa (160 species) and absent in Australia (Goodall-Copestake et al, 2010). The genus is thought to have originated in Africa, while South American and South East Asian species are the results of parallel radiations over the last 20 -50 million years (Goodall Copestake et al, 2010;Plana et al, 2004;Thomas et al, 2011). Long distance dispersal is rare, for example Begonia species have failed to cross the Torres strait from Papua New Guinea to Australia.…”

“…The phylogenetic relationships within the relatively small group of African Begonia, which comprises around 160 species subdivided into 17 sections (de Wilde & Plana, 2003;Doorenbos et al, 1998), are relatively well understood. African Begonia species are not retrieved as monophyletic, but South African species placed in section Augustia were shown to be closely related to a clade of American taxa, and Socotran Begonia species (section Peltaugustia) were shown to form a monophyletic clade with Asian taxa (Forrest et al, 2005;Goodall-Copestake et al, 2010;Plana et al, 2004;Thomas et al, 2011). Revisions exist for the majority of the African sections (see references in Plana, 2003), and the intersectional relationships of African Begonia species have been studied using molecular systematic approaches and have been discussed in some detail in Plana (2003) and Plana et al (2004).…”

“…African Begonia species are not retrieved as monophyletic, but South African species placed in section Augustia were shown to be closely related to a clade of American taxa, and Socotran Begonia species (section Peltaugustia) were shown to form a monophyletic clade with Asian taxa (Forrest et al, 2005;Goodall-Copestake et al, 2010;Plana et al, 2004;Thomas et al, 2011). Revisions exist for the majority of the African sections (see references in Plana, 2003), and the intersectional relationships of African Begonia species have been studied using molecular systematic approaches and have been discussed in some detail in Plana (2003) and Plana et al (2004). Most African sections are well circumscribed and seem to represent monophyletic taxa, but section Mezierea is polyphyletic (Forrest et al, 2005;Plana, 2003;Plana et al, 2004); and the lack of resolution or support in phylogenies makes the assessment of the monophyly of some sections problematic.…”

“…Revisions exist for the majority of the African sections (see references in Plana, 2003), and the intersectional relationships of African Begonia species have been studied using molecular systematic approaches and have been discussed in some detail in Plana (2003) and Plana et al (2004). Most African sections are well circumscribed and seem to represent monophyletic taxa, but section Mezierea is polyphyletic (Forrest et al, 2005;Plana, 2003;Plana et al, 2004); and the lack of resolution or support in phylogenies makes the assessment of the monophyly of some sections problematic. Apart from the grade of continental African taxa, a major Madagascan radiation can be detected.…”