Early Tertiary Out-of-India Dispersal of Crypteroniaceae: Evidence From Phylogeny and Molecular Dating

Abstract

Phylogenetic analyses and molecular dating estimates based on chloroplast DNA sequences were used to establish the relationships of the southern and Southeast Asian Crypteroniaceae and elucidate their biogeographic history. Maximum parsimony and likelihood analyses of rbcL sequences suggested that Crypteroniaceae should be restricted to Crypteronia, Axinandra, and Dactylocladus and that Crypteroniaceae, so defined, are sister to a clade formed by three small African taxa (Oliniaceae, Penaeaceae, and Rhynchocalycaceae) and the monotypic Central and South American Alzateaceae. Three molecular dating approaches (maximum-likelihood under a molecular clock, Langley-Fitch, and penalized-likelihood) were used to infer the age of Crypteroniaceae using both paleobotanic and geologic calibrations. Comparisons among these three methods revealed significant lineage effects in rbcL sequences. Clock-independent dating estimates suggested that divergence of Crypteroniaceae from its African and South American relatives coincided with the breakup of Gondwana, and that India likely served as a "raft" transporting Crypteroniaceae to Asia, with later expansion to Southeast Asia. To our knowledge, Crypteroniaceae are the first plant group for which the out-of-India hypothesis is well corroborated by molecular-based estimates of divergence times.

Alien fungal species distribution: the study case of Favolaschia calocera

“…Phylogenetic and dating analyses have confirmed an out-of-India migration in ranid frogs (Bossuyt and Milinkovitch 2001), acrodont lizards (Macey et al 2000), ratite birds (Cooper et al 2001), and there is strong evidence to support the same pattern in some plants (e.g. Crypteroniaceae, Conti et al 2002, Rutschmann et al 2004Caesalpiniaceae, Dipterocarpaceae and Uapacaceae, Dayanandan et al 1999, Lavin et al 2005, Moyersoen 2006Sarcolaenaceae, Ducousso et al 2004).…”

Assessing Calibration Uncertainty in Molecular Dating: The Assignment of Fossils to Alternative Calibration Points

“…In many dated chronograms, only one possible assignment exists, because only one taxon was sampled from the pertinent group (e.g., the assignment of fossil Melastomataceae leaves in Conti et al, 2002, or the assignment of fossil Eucalyptoid fruits in Sytsma et al, 2004; see also Sanderson and Doyle, 2001). Although unequivocal, this procedure is hardly satisfactory.…”

The evolution of African plant diversity

“…In the Late Cretaceous and Paleogene, India was adjacent to East Africa and may have formed a bridge to south-east Asia (Conti et al, 2002;Rutschmann et al, 2004). Connections across the Atlantic Ocean have generally be regarded to be the result of long distance dispersal by wind or ocean current, and here, too, many disjunctions have been documented (Thorne, 1973;Renner, 2004).…”