Adama Faye - Academia.edu (original) (raw)
Papers by Adama Faye
Land use impacts and their contribution to climate change ..
Land use impacts and their contribution to climate change ..
Botanical Journal of the Linnean Society, 2016
Even though African rain forests display high levels of local species diversity and endemism, the... more Even though African rain forests display high levels of local species diversity and endemism, their lower continental species diversity when compared with the Neotropics and Asia is paradoxical. This disparity is mainly thought to be linked to either important extinction events during the Pleistocene or at the Eocene-Oligocene boundary. African rattans or climbing palms are one of the most diverse clades of palms in Africa, representing one-third of all known species. Here, we reconstruct the phylogeny and temporal evolution of African rattans (Arecaceae: Calamoideae: Lepidocaryeae: Ancistrophyllinae) to test the two main hypotheses of palm evolution in Africa. We constructed a near-complete, dated species-level phylogenetic tree for subtribe Ancistrophyllinae using plastid and nuclear markers. The generic relationships between Ancistrophyllinae were fully resolved and species-level relationships are well to weakly supported. Ancistrophyllinae diversified during the Eocene with most species originating during the late Miocene after 10 Mya. This result is in agreement with several other studies suggesting a pre-Pleistocene origin of the extant African flora. Ancistrophyllinae display an anti-sigmoidal lineage-through-time plot with a moderate overall extinction fraction. Our simulations suggest important roles for an ancient extinction event at the Oligocene-Eocene boundary. In contrast, the hypothesis of an important extinction event in palms during the late Pliocene at 3 Mya is not supported. We suggest that the evolutionary history of African rattans has undergone a constant diversification rate punctuated by one or several important extinction events during the first part of the Cenozoic with most species diversity accumulating during the late Miocene and Pliocene.
Understanding the evolutionary patterns of genetic diversity of cultivated plants and their wild ... more Understanding the evolutionary patterns of genetic diversity of cultivated plants and their wild relatives is a fundamental aspect of agrobiodiversity research. Documenting genetic diversity and understanding the evolutionary histories of crops will have important impacts in terms of food security in southern countries such as Africa. In this study, we develop a generalized method for sequencing full chloroplast genomes via hybridization enrichment suitable for multiplexing a large number of individuals. We will present application of the method to the study of wild pearl millet, wild and cultivated yams, fonio and to African rice.
Systematic Botany, 2014
Over one third of African palms are rattans, e.g. climbing palms. The subtribe Ancistrophyllinae ... more Over one third of African palms are rattans, e.g. climbing palms. The subtribe Ancistrophyllinae (subfamily Calamoideae) contains most of these with 21 species represented by three genera: Eremospatha, Laccosperma, and Oncocalamus. African rattans are mainly restricted to the tropical rain forests of Central and West Africa and play an important role in the local economy thanks to their use in furniture making. Here, we present a species level phylogeny of the Ancistrophyllinae based on four plastid intergenic spacers (psbA-trnH, psbZ-trnfM, atpI-atpH, and rps3-rpl16) sequenced for 80% of the species found in the subtribe (17/21). Data were analyzed using maximum parsimony, maximum likelihood, and Bayesian inference methods. Our results show that subtribe Ancistrophyllinae is strongly supported as monophyletic, as are the three genera. However, relationships among the genera remain unresolved. Our analyses provide details on the relationships among species within Eremospatha and Laccosperma, but not in Oncocalamus. The species E. cabrae and E. dransfieldii were recovered with strong support as sister, together forming a highly divergent clade sister to the rest of the genus. The four plastid markers used here provide useful levels of resolution and could be considered in other species-level analyses in palms.
Several hypotheses have been advanced to explain the paucity of the African palm flora. The main ... more Several hypotheses have been advanced to explain the paucity of the African palm flora. The main hypothesis stipulates that palms underwent high extinction rates linked to an increase in aridity of the climate since the Miocene (Moore 1973; Morley 2000) leading to fewer species than in other tropical regions. This was supported to some extent by the fossil record (Pan et al. 2005) and by a worldwide ecological study of palms (Kissling et al. 2012). In contrast, a study of global diversification rates at the family level did not detect a significant decrease in rates for African palms (Baker & Couvreur 2012), suggesting that African palms might not have been affected by the change in climate as previously suggested. However, to date, detailed knowledge of palm species evolutionary dynamics are lacking hampering any solid understanding of palm history in Africa. To this end, we shall reconstruct the phylogeny in order to understand the evolutionary dynamics of the African rattan clade, Ancistrophyllineae. This clade comprises three genera representing 21
Molecular Ecology Resources, 2014
Land use impacts and their contribution to climate change ..
Land use impacts and their contribution to climate change ..
Botanical Journal of the Linnean Society, 2016
Even though African rain forests display high levels of local species diversity and endemism, the... more Even though African rain forests display high levels of local species diversity and endemism, their lower continental species diversity when compared with the Neotropics and Asia is paradoxical. This disparity is mainly thought to be linked to either important extinction events during the Pleistocene or at the Eocene-Oligocene boundary. African rattans or climbing palms are one of the most diverse clades of palms in Africa, representing one-third of all known species. Here, we reconstruct the phylogeny and temporal evolution of African rattans (Arecaceae: Calamoideae: Lepidocaryeae: Ancistrophyllinae) to test the two main hypotheses of palm evolution in Africa. We constructed a near-complete, dated species-level phylogenetic tree for subtribe Ancistrophyllinae using plastid and nuclear markers. The generic relationships between Ancistrophyllinae were fully resolved and species-level relationships are well to weakly supported. Ancistrophyllinae diversified during the Eocene with most species originating during the late Miocene after 10 Mya. This result is in agreement with several other studies suggesting a pre-Pleistocene origin of the extant African flora. Ancistrophyllinae display an anti-sigmoidal lineage-through-time plot with a moderate overall extinction fraction. Our simulations suggest important roles for an ancient extinction event at the Oligocene-Eocene boundary. In contrast, the hypothesis of an important extinction event in palms during the late Pliocene at 3 Mya is not supported. We suggest that the evolutionary history of African rattans has undergone a constant diversification rate punctuated by one or several important extinction events during the first part of the Cenozoic with most species diversity accumulating during the late Miocene and Pliocene.
Understanding the evolutionary patterns of genetic diversity of cultivated plants and their wild ... more Understanding the evolutionary patterns of genetic diversity of cultivated plants and their wild relatives is a fundamental aspect of agrobiodiversity research. Documenting genetic diversity and understanding the evolutionary histories of crops will have important impacts in terms of food security in southern countries such as Africa. In this study, we develop a generalized method for sequencing full chloroplast genomes via hybridization enrichment suitable for multiplexing a large number of individuals. We will present application of the method to the study of wild pearl millet, wild and cultivated yams, fonio and to African rice.
Systematic Botany, 2014
Over one third of African palms are rattans, e.g. climbing palms. The subtribe Ancistrophyllinae ... more Over one third of African palms are rattans, e.g. climbing palms. The subtribe Ancistrophyllinae (subfamily Calamoideae) contains most of these with 21 species represented by three genera: Eremospatha, Laccosperma, and Oncocalamus. African rattans are mainly restricted to the tropical rain forests of Central and West Africa and play an important role in the local economy thanks to their use in furniture making. Here, we present a species level phylogeny of the Ancistrophyllinae based on four plastid intergenic spacers (psbA-trnH, psbZ-trnfM, atpI-atpH, and rps3-rpl16) sequenced for 80% of the species found in the subtribe (17/21). Data were analyzed using maximum parsimony, maximum likelihood, and Bayesian inference methods. Our results show that subtribe Ancistrophyllinae is strongly supported as monophyletic, as are the three genera. However, relationships among the genera remain unresolved. Our analyses provide details on the relationships among species within Eremospatha and Laccosperma, but not in Oncocalamus. The species E. cabrae and E. dransfieldii were recovered with strong support as sister, together forming a highly divergent clade sister to the rest of the genus. The four plastid markers used here provide useful levels of resolution and could be considered in other species-level analyses in palms.
Several hypotheses have been advanced to explain the paucity of the African palm flora. The main ... more Several hypotheses have been advanced to explain the paucity of the African palm flora. The main hypothesis stipulates that palms underwent high extinction rates linked to an increase in aridity of the climate since the Miocene (Moore 1973; Morley 2000) leading to fewer species than in other tropical regions. This was supported to some extent by the fossil record (Pan et al. 2005) and by a worldwide ecological study of palms (Kissling et al. 2012). In contrast, a study of global diversification rates at the family level did not detect a significant decrease in rates for African palms (Baker & Couvreur 2012), suggesting that African palms might not have been affected by the change in climate as previously suggested. However, to date, detailed knowledge of palm species evolutionary dynamics are lacking hampering any solid understanding of palm history in Africa. To this end, we shall reconstruct the phylogeny in order to understand the evolutionary dynamics of the African rattan clade, Ancistrophyllineae. This clade comprises three genera representing 21
Molecular Ecology Resources, 2014