The evolution and phylogeography of the African elephant inferred from mitochondrial DNA sequence and nuclear microsatellite markers

Recent genetic results support the recognition of two African elephant species: Loxodonta africana, the savannah elephant, and Loxodonta cyclotis, the forest elephant. The study, however, did not include the populations of West Africa, where the taxonomic affinities of elephants have been much debated. We examined mitochondrial cytochrome b control region sequences and four microsatellite loci to investigate the genetic differences between the forest and savannah elephants of West and Central Africa. We then combined our data with published control region sequences from across Africa to examine patterns at the continental level. Our analysis reveals several deeply divergent lineages that do not correspond with the currently recognized taxonomy: (i) the forest elephants of Central Africa; the forest and savannah elephants of West Africa; and (iii) the savannah elephants of eastern, southern and Central Africa. We propose that the complex phylogeographic patterns we detect in African elephants result from repeated continental-scale climatic changes over their five-to-six million year evolutionary history. Until there is consensus on the taxonomy, we suggest that the genetic and ecological distinctness of these lineages should be an important factor in conservation management planning.     

The roles of rivers and Pleistocene refugia in shaping genetic diversity in Praomys misonnei in tropical Africa

Aim This study aims to elucidate the phylogeography of the murid rodent Praomys misonnei and to document whether or not rain forest refugia and rivers structure patterns of diversity within this species. Location Tropical Africa, from Ghana to Kenya. Methods Patterns of genetic structure and signatures of population history (cytochrome b gene) were assessed in a survey of 229 individuals from 54 localities. Using maximum likelihood, Bayesian, network and genetic structure analyses, we inferred intra‐specific relationships and tested hypotheses for historical patterns of gene flow within P. misonnei. Results Our phylogenetic analyses reveal a strong phylogeographical structure. We identified four major geographical clades within P. misonnei: one clade in Ghana and Benin, a Nigerian clade, a West Central African clade and a Central and East African clade. Several subclades were identified within these four major clades. A signal of population expansion was detected in most clades or subclades. Coalescence within all of the major clades of P. misonnei occurred during the Middle Pleistocene and/or the beginning of Late Pleistocene. Main conclusions Our results suggest a role for both Pleistocene refugia and rivers in structuring genetic diversity in P. misonnei. This forest‐dwelling rodent may have been isolated in a number of forest fragments during arid periods and expanded its range during wetter periods. Potential forest refugia may have been localized in Benin–Ghana, south‐western Cameroon, southern Gabon, northern Gabon and eastern Democratic Republic of Congo–western Uganda. The Niger and/or the Cross Rivers, the Oubangui‐Congo, Sanaga, Ogooue and/or Ivindo Rivers probably stopped the re‐expansion of the species from relict areas.     

Phylogeography of Mus (Nannomys) minutoides (Rodentia,Muridae) in West Central African savannahs: singular vicariance in neighbouring populations

We studied the phylogeography of the strict savannah pygmy mice Mus (Nannomys) minutoides in West Central Africa. A total of 846 base pairs of the cytochrome b sequence were obtained for 66 individuals collected in Gabon, Cameroon, Republic of Congo and Central African Republic. These sequences were compared to those of M. minutoides from other African countries and to eight other species of the genus Mus. We performed maximum likelihood, Bayesian and nested clade analyses, as well as neutrality tests and time estimates. We show that M. minutoides is a well‐differentiated monophyletic species that separated from other pygmy mice 1.17 Myr ago. A distinct West Central African M. minutoides clade diverged early from the other African populations of the species, with a more recent common ancestor dating 0.14 Myr. West Central African populations are globally homogeneous, despite the present fragmentation of savannahs by the rain forest. However, our analyses show an unexpected vicariance between geographically close savannahs, embedded in the rain forest in Central Gabon. One of these populations is genetically more similar to very distant peripheral populations than to three closely neighbouring populations situated on both sides of the Ogooué River. A non‐river geographical barrier probably persisted in this area, durably isolating these local populations. This hypothesis about the history of the savannah landscape should be testable through the biogeographical analysis of other strict savannah small mammal species.     

Predicting alpha diversity of African rain forests: models based on climate and satellite‐derived data do not perform better than a purely spatial model

Aim Our aim was to evaluate the extent to which we can predict and map tree alpha diversity across broad spatial scales either by using climate and remote sensing data or by exploiting spatial autocorrelation patterns. Location Tropical rain forest, West Africa and Atlantic Central Africa. Methods Alpha diversity estimates were compiled for trees with diameter at breast height ≥ 10 cm in 573 inventory plots. Linear regression (ordinary least squares, OLS) and random forest (RF) statistical techniques were used to project alpha diversity estimates at unsampled locations using climate data and remote sensing data [Moderate Resolution Imaging Spectroradiometer (MODIS), normalized difference vegetation index (NDVI), Quick Scatterometer (QSCAT), tree cover, elevation]. The prediction reliabilities of OLS and RF models were evaluated using a novel approach and compared to that of a kriging model based on geographic location alone. Results The predictive power of the kriging model was comparable to that of OLS and RF models based on climatic and remote sensing data. The three models provided congruent predictions of alpha diversity in well‐sampled areas but not in poorly inventoried locations. The reliability of the predictions of all three models declined markedly with distance from points with inventory data, becoming very low at distances > 50 km. According to inventory data, Atlantic Central African forests display a higher mean alpha diversity than do West African forests. Main conclusions The lower tree alpha diversity in West Africa than in Atlantic Central Africa may reflect a richer regional species pool in the latter. Our results emphasize and illustrate the need to test model predictions in a spatially explicit manner. Good OLS or RF model predictions from inventory data at short distance largely result from the strong spatial autocorrelation displayed by both the alpha diversity and the predictive variables rather than necessarily from causal relationships. Our results suggest that alpha diversity is driven by history rather than by the contemporary environment. Given the low predictive power of models, we call for a major effort to broaden the geographical extent and intensity of forest assessments to expand our knowledge of African rain forest diversity.     

Local and regional ecological morphology of dung beetle assemblages across four biogeographic regions

Aim Niche partitioning within species assemblages is thought to influence species packing and/or total niche space occupied. The evolution of dung beetles (Scarabaeinae) is likely to have been strongly influenced by inter‐specific competition, leading to niche partitioning. We consider whether local‐scale processes leave a signature in regional patterns of functional diversity in dung beetle assemblages, and investigate the correlation between total exploited ecomorphological space and density of species packing with increased species richness. We test whether ecomorphological space occupied by local assemblages reflects that of their regional species pool, and the extent to which ecomorphological space is convergent or divergent within functional groups across regional pools. Location Neotropics, Africa, Australia and Madagascar. Methods Dung beetle assemblages were collected in a standardized manner from four biogeographic regions. Ecomorphological similarity among the assemblages was assessed by multivariate analysis of 19 linear measurements for 300 species and three functional nesting types (roller, tunneller or dweller), firstly on a local level within the Neotropics and Afrotropics, and then between the regional species pools. Results Key body measurements, in particular the hind tibia, separated rollers and tunnellers into largely non‐overlapping entities along the first three axes of the shape analysis. Three Neotropical assemblages, which vary widely in species numbers, each harboured a similar amount of morphometric variation, resulting in increasingly dense species packing with greater species richness. Similar findings were obtained in two South African assemblages. Assemblages in the four biogeographic regions showed largely similar distributions of ecomorphological variation, including the separation of rollers and tunnellers, despite their distant phylogenetic relationships. Ecomorphological similarity among regions was particularly high in tunnellers, whilst the rollers exhibited greater regional differentiation. Main conclusions Local assemblages evidently represent the full diversity of functional groups available in the regional pool, even in species‐poor assemblages. There is a strong trend towards convergence in morphology separating tunnellers and rollers in phylogenetically independent lineages. The ecomorphological similarity of regional assemblages suggests that morphological convergence is the result of common selective forces active within the assemblages themselves. This lends support to the widely hypothesized effect of inter‐specific interactions and niche partitioning in determining assemblage composition and lineage evolution in the Scarabaeinae.     

Genetic diversity,evolutionary history and implications for conservation of the lion (Panthera leo) in West and Central Africa

Aim In recent decades there has been a marked decline in the numbers of African lions (Panthera leo), especially in West Africa where the species is regionally endangered. Based on the climatological history of western Africa, we hypothesize that West and Central African lions have a unique evolutionary history, which is reflected by their genetic makeup. Location Sub‐Saharan Africa and India, with special focus on West and Central Africa. Method In this study 126 samples, throughout the lion’s complete geographic range, were subjected to phylogenetic analyses. DNA sequences of a mitochondrial region, containing cytochrome b, tRNAPro, tRNAThr and the left part of the control region, were analysed. Results Bayesian, maximum likelihood and maximum parsimony analyses consistently showed a distinction between lions from West and Central Africa and lions from southern and East Africa. West and Central African lions are more closely related to Asiatic lions than to the southern and East African lions. This can be explained by a Pleistocene extinction and subsequent recolonization of West Africa from refugia in the Middle East. This is further supported by the fact that the West and Central African clade shows relatively little genetic diversity and is therefore thought to be an evolutionarily young clade. Main conclusions The taxonomic division between an African and an Asian subspecies does not fully reflect the overall genetic diversity within lions. In order to conserve genetic diversity within the species, genetically distinct lineages should be prioritized. Understanding the geographic pattern of genetic diversity is key to developing conservation strategies, both for in situ management and for breeding of captive stocks.     

Patterns of species richness and turnover in endemic amphibians of the Guineo-Congolian rain forest

Aim

The African Guineo-Congolian (GC) region is a global biodiversity hotspot with high species endemism, bioclimatic heterogeneity, complex landscape features, and multiple biogeographic barriers. Bioclimatic and geographic variables influence global patterns of species richness and endemism, but their relative importance varies across taxa and regions and is poorly understood for many faunas. Here, we test the hypothesis that turnover in endemic amphibians of the GC biodiversity hotspot is influenced mainly by the geographic distance between grid cells and secondarily by rainfall- and temperature-related variables.

Location

West and Central Africa.

Major Taxa Studied

Amphibians.

Methods

We compiled species-occurrence records via field sampling, online databases, and taxonomic literature. Our study used 1205 unique georeferenced records of 222 amphibian species endemic to the GC region. Patterns of species richness were mapped onto a grid with a spatial resolution of 0.5° × 0.5°. We estimated weighted endemism and tested whether endemism was higher than the expected species richness (randomization test). We quantified species turnover using generalized dissimilarity modelling to evaluate the processes underlying observed patterns of species richness in GC endemic amphibians. We explored bioregionalization using agglomerative hierarchical clustering based on the unweighted pair group method with arithmetic averages.

Results

We identified seven areas within the lower GC region – forests in Cameroon, Gabon, Southern Nigeria, Equatorial Guinea, Republic of Congo, Democratic Republic of Congo, and Cote d'Ivoire – as having high species richness of endemic amphibians. The randomization test returned four major areas of significant weighted endemism: Nigeria-Cameroon mountains, forest regions of the Democratic Republic of Congo, Cote d'Ivoire, and Ghana. Our analysis revealed five bioregions for amphibian endemism, four of which were located within the lower Guineo-Congolian forest. Species turnover was strongly related to the geographic distance between grid cells; contributing bioclimatic variables included precipitation of the warmest quarter, mean temperature of the wettest quarter, and mean diurnal temperature range.

Main Conclusions

Our results indicate that geographic distance between grid cells is the primary determinant of turnover in GC endemic amphibians, with secondary but significant effects of rainfall- and temperature-related variables. Our study identifies key areas of endemic amphibian richness that could be prioritized for conservation actions.     

Small mammal community structure in West Africa: a meta‐analysis using null models

Peer‐reviewed studies on the community structure of small mammals (Rodentia and Soricomorpha) from the Gulf of Guinea region of West Africa were reviewed. To detect nonrandom patterns in the various assemblages under study, the original datasets were re‐analysed using null models [two independent randomization algorithms (RA) for niche overlap] and Monte Carlo simulations. The total species richness in the countries considered in this review was 45 species for soricomorphs and 101 for rodents, and the studies reviewed here reported data for 53.3% of these soricomorph species and for 76.2% of these rodent species. Nonrandom habitat niche partitioning was rarely observed in both rodents and soricomorphs. Instead, aggregated use of habitat resources was frequently detected in both groups. Forest habitat was generally selected as aggregating resource type by small mammal assemblages. Thus, contrary to expectations, our review revealed little evidence for interspecific competition along the habitat niche axis in West African small mammals. However, it is possible that the aggregated use of the forest resource by small mammal species may be apparent, but that the various species partitioned space at a lower scale, for instance selecting different microhabitats. Interspecific competition appeared to be stronger in altered habitats, as predicted by previous studies on other forest organisms in West Africa.     

Prevalence and genetic diversity of Batrachochytrium dendrobatidis in Central African island and continental amphibian communities

The fungal pathogen Batrachochytrium dendrobatidis (Bd) infects hundreds of amphibian species and is implicated in global amphibian declines. Bd is comprised of several lineages that differ in pathogenicity, thus, identifying which Bd strains are present in a given amphibian community is essential for understanding host–pathogen dynamics. The presence of Bd has been confirmed in Central Africa, yet vast expanses of this region have not yet been surveyed for Bd prevalence, and the genetic diversity of Bd is largely unknown in this part of the world. Using retrospective surveys of museum specimens and contemporary field surveys, we estimated the prevalence of Bd in Central African island and continental amphibian assemblages, and genotyped strains of Bd present in each community. Our sampling of museum specimens included just a few individuals collected in the Gulf of Guinea archipelago prior to 1998, yet one of these individuals was Bd‐positive indicating that the pathogen has been on Bioko Island since 1966. We detected Bd across all subsequent sample years in our study and found modest support for a relationship between host life history and Bd prevalence, a positive relationship between prevalence and host community species richness, and no significant relationship between elevation and prevalence. The Global Panzootic Lineage (BdGPL) was present in all the island and continental amphibian communities we surveyed. Our results are consistent with a long‐term and widespread distribution of Bd in amphibian communities of Gabon and the Gulf of Guinea archipelago.     

Reptile, amphibian, and lemur diversity of the Malahelo Forest, a biogeographical transition zone in southeastern Madagascar

Ambatorongorongo Mountain lies at the historical intersection betweenhumid, spiny, and littoral forests in southeastern Madagascar. We report theresults of surveys of the herpetofauna and lemurs occurring in Malahelo Forest,a small (<25 ha) forest fragment lying on the western slope ofAmbatorongorongo Mountain. There are at least 41 reptile, 11 amphibian, and 7lemur species in this forest, including several that are endemic to southeasternMadagascar and are at severe risk of extinction. The species richness of theMalahelo fauna is comparable to that of even the largest forest reserves in theregion. We also evaluate the similarity of the Malahelo herpetofauna to that ofnearby humid, spiny, and littoral forests to assess the biogeographic affinitiesof its amphibians and reptile assemblages. Both groups contain speciescharacteristic of each of the three surrounding forest types, but thebiogeographic patterns appear to differ for amphibians and reptiles. Overall,the herpetofauna and lemurs of the Malahelo Forest indicate that it is a remnantof a biogeographic transition zone between the major forest types ofsoutheastern Madagascar. The combination of high species richness, regionalendemics, and unique herpetofaunal and lemur assemblages should make MalaheloForest a high conservation priority, and we give recommendations for protectingwhat remains of this important transitional forest.     

The biogeographical assignment of a west Kenyan rain forest remnant: further evidence from analysis of its reptile fauna

Aim The Kakamega Forest, western Kenya, has been biogeographically assigned to both lowland and montane forest biomes, or has even been considered to be unique. Most frequently it has been linked with the Guineo‐Congolian rain forest block. The present paper aims to test six alternative hypotheses of the zoogeographical relationships between this forest remnant and other African forests using reptiles as a model group. Reptiles are relatively slow dispersers, compared with flying organisms (Aves and Odonata) on which former hypotheses have been based, and may thus result in a more conservative biogeographical analysis. Location Kakamega Forest, Kenya, Sub‐Saharan Africa. Methods The reptile diversity of Kakamega Forest was evaluated by field surveys and data from literature resources. Faunal comparisons of Kakamega Forest with 16 other African forests were conducted by the use of the ‘coefficient of biogeographic resemblance’ using the reptile communities as zoogeographic indicators. Parsimony Analysis of Endemism and Neighbour Joining Analysis of Endemism were used to generate relationship trees based on an occurrence matrix with paup *. Results The analysis clearly supports the hypothesis that the Kakamega Forest is the easternmost fragment of the Guineo‐Congolian rain forest belt, and thus more closely related to the forests of that Central–West African complex than to any forest further east, such as the Kenyan coastal forests. Many Kenyan reptile species occur exclusively in the Kakamega Forest and its associated forest fragments. Main conclusions The Kakamega Forest is the only remnant of the Guineo‐Congolian rain forest in the general area. We assume that the low degree of resemblance identified for the Guineo‐Congolian forest and the East African coastal forest reflect the long history of isolation of the two forest types from each other. Kenyan coastal forests may have been historically connected through forest ‘bridges’ of the southern highlands with the Congo forest belt, allowing reptile species to migrate between them. The probability of a second ‘bridge’ located in the region of southern Tanzanian inselbergs is discussed. Although not particularly rich in reptile species, the area should be considered of high national priority for conservation measures.     

Palaeobotanical studies from tropical Africa: relevance to the evolution of forest, woodland and savannah biomes

Fossil plants provide data on climate, community composition and structure, all of which are relevant to the definition and recognition of biomes. Macrofossils reflect local vegetation, whereas pollen assemblages sample a larger area. The earliest solid evidence for angiosperm tropical rainforest in Africa is based primarily on Late Eocene to Late Oligocene (ca. 39-26 Myr ago) pollen assemblages from Cameroon, which are rich in forest families. Plant macrofossil assemblages from elsewhere in interior Africa for this time interval are rare, but new work at Chilga in the northwestern Ethiopian Highlands documents forest communities at 28 Myr ago. Initial results indicate botanical affinities with lowland West African forest. The earliest known woodland community in tropical Africa is dated at 46 Myr ago in northern Tanzania, as documented by leaves and fruits from lake deposits. The community around the lake was dominated by caesalpinioid legumes, but included Acacia, for which this, to my knowledge, is the earliest record. This community is structurally similar to modern miombo, although it is different at the generic level. The grass-dominated savannah biome began to expand in the Middle Miocene (16 Myr ago), and became widespread in the Late Miocene (ca. 8 Myr ago), as documented by pollen and carbon isotopes from both West and East Africa.     

Phylogenetic position of the endemic Mount Oku rat,Lamottemys okuensis (Rodentia: Muridae), based on molecular and morphological data

Lamottemys okuensis Petter, 1986, is restricted to the Mount Oku montane forest in the central‐northern part of the Cameroon Volcanic Line (CVL; Central West Africa). It is endangered and has a decreasing population trend. The genus is monotypic and little is known about its phylogeny and evolutionary history. Using both molecular and morphological evidence, we tested two competing systematic hypotheses involving Lamottemys: whether it is more closely related to Desmomys or to Oenomys. We also discuss Lamottemys’ biogeographical origin. Molecular phylogenies indicated a sister‐group relationship with the Ethiopian montane forest endemic genus Desmomys. This reinforces the hypothesis of recurrent connections over time between West and East African mountains, probably facilitated by climate changes that led to expansions and contractions of montane environments. Our molecular dating, consistent with a period of intense volcanic activity in Central East Africa and the CVL, suggests that the geological history of East and Central Africa also contributed to promoting the isolation of Lamottemys in the CVL. Moreover, this study provides the most comprehensive phylogenetic analysis for the whole tribe Arvicanthini, sampling 17 of the 18 member genera. In this rodent group, stephanodonty probably appeared independently with grasses expansion. These habitat changes probably promoted the evolution of specialist rodents able to feed on abrasive vegetal matter by a dental adaptation.     

Climate change alters plant biogeography in Mediterranean prairies along the West Coast,USA

Projected changes in climate are expected to have widespread effects on plant community composition and diversity in coming decades. However, multisite, multifactor climate manipulation studies that have examined whether observed responses are regionally consistent and whether multiple climate perturbations are interdependent are rare. Using such an experiment, we quantified how warming and increased precipitation intensity affect the relative dominance of plant functional groups and diversity across a broad climate gradient of Mediterranean prairies. We implemented a fully factorial climate manipulation of warming (+2.5–3.0 °C) and increased wet‐season precipitation (+20%) at three sites across a 520‐km latitudinal gradient in the Pacific Northwest, USA. After seeding with a nearly identical mix of native species at all sites, we measured plant community composition (i.e., cover, richness, and diversity), temperature, and soil moisture for 3 years. Warming and the resultant drying of soils altered plant community composition, decreased native diversity, and increased total cover, with warmed northern communities becoming more similar to communities further south. In particular, after two full years of warming, annual cover increased and forb cover decreased at all sites mirroring the natural biogeographic pattern. This suggests that the extant climate gradient of increasing heat and drought severity is responsible for a large part of the observed biogeographic pattern of increasing annual invasion in US West Coast prairies as one moves further south. Additional precipitation during the rainy season did little to relieve drought stress and had minimal effects on plant community composition. Our results suggest that the projected increase in drought severity (i.e., hotter, drier summers) in Pacific Northwest prairies may lead to increased invasion by annuals and a loss of forbs, similar to what has been observed in central and southern California, resulting in novel species assemblages and shifts in functional composition, which in turn may alter ecosystem functions.     

Phylogeographic structure and regional history of Lemniscomys striatus (Rodentia: Muridae) in tropical Africa

Aim This study aims to elucidate the phylogeography of the murid rodent Lemniscomys striatus and to evaluate the relative roles of ecological change, habitat patchiness, rivers and geological barriers in structuring patterns of diversity. Location Sub‐Saharan Africa. Methods The extent of phylogeographic patterns and molecular genetic diversity (cytochrome b gene) were addressed in a survey of 128 individuals of L. striatus from 42 localities. Using maximum parsimony, maximum likelihood, Bayesian, network and genetic structure analyses, we inferred intraspecific relationships and tested hypotheses for historical patterns of gene flow within L. striatus. Results Our results identified four major geographical clades within L. striatus: a West African clade, a Benin‐Nigeria clade, a Central African clade, and an East African clade. Several subclades were identified within these four major clades. Restricted gene flow with isolation by distance was recorded, which is congruent with the low dispersal ability of such a small murid rodent. No clear signal of population expansion was detected within clades or subclades. Main conclusions The western rift system and the Volta and Niger rivers may have acted as long‐term extrinsic barriers to gene flow, resulting in the emergence of the four main clades of L. striatus. The observed pattern of mitochondrial variation observed within each clade probably results from late Pleistocene climatic and vegetation changes: during adverse conditions (forest expansion), L. striatus may have survived only in refugia, and then experienced range expansion under favourable conditions (savanna expansion).     

Evidence of history in explaining diversity patterns in tropical riverine fish

Aim Documentation of the ongoing effect of rain forest refuges at the last glacial maximum (LGM) on patterns of tropical freshwater fish diversity. Location Tropical South and Central America, and West Africa. Methods LGM rain forest regions and species richness by drainage were compiled from published data. GIS mapping was applied to compile drainage area and contemporary primary productivity. We used multiple regression analyses, applied separately for Tropical South America, Central America and West Africa, to assess differences in species richness between drainages that were connected and disconnected to rain forest refuge zones during the LGM. Spatial autocorrelation of the residuals was tested using Moran's I statistic. We added an intercontinental comparison to our analyses to see if a historical signal would persist even when a regional historical effect (climate at the LGM) had already been accounted for. Results Both area and history (contact with LGM rain forest refuge) explained the greatest proportions of variance in the geographical pattern of riverine species richness. In the three examined regions, we found highest richness in drainages that were connected to the rain forest refuges. No significant residual spatial autocorrelation was detected after considering area, primary productivity and LGM rain forest refuges. These results show that past climatic events still affect West African and Latin American regional and continental freshwater fish richness. At the continental scale, we found South American rivers more species‐rich than expected on the basis of their area, productivity and connectedness to rain forest refuge. Conversely, Central American rivers were less species‐diverse than expected by the grouped model. African rivers were intermediate. Therefore, a historical signal persists even when a regional historical effect (climate at the LGM) had already been accounted for. Main conclusions It has been hypothesized that past climatic events have limited impact on species richness because species have tracked environmental changes through range shifts. However, when considering organisms with physically constrained dispersal (such as freshwater fish), past events leave a perceptible imprint on present species diversity. Furthermore, we considered regions that have comparable contemporary climatic and environmental characteristics, explaining the absence of a productivity effect. From the LGM to the present day (a time scale of 18,000 years), extinction processes should have played a predominant role in shaping the current diversity pattern. By contrast, the continental effects could reflect historical contingencies explained by differences in speciation and extinction rates between continents at higher time scales (millions of years).     

Taxonomy of the African giant pouched rats (Nesomyidae: Cricetomys): molecular and craniometric evidence support an unexpected high species diversity

Our study combined a mitochondrial cytochrome b phylogeny with cranial measurements from giant pouched rats collected across sub‐Saharan Africa. The mitochondrial phylogeny resolves two West African clades and a clade with east and central Africa representatives. This last clade can be further divided into four subclades. Altogether they represent six species (Cricetomys gambianus, Cricetomys ansorgei, Cricetomys emini, and three undescribed taxa) that can be distinguished on the basis of their mitochondrial DNA sequences and craniometry. In the absence of adequate craniometric data the existence of Cricetomys kivuensis cannot be confirmed by our data. Our combined molecular and craniometric data allowed us to broadly delineate the distribution ranges of the detected species. Cricetomys gambianus occurs in the savannah and forest clearings of West Africa. Cricetomys ansorgei is distributed in the savannah of East and southern Africa. Cricetomys emini, as currently recognized across the Guineo‐Congolian forest of Africa, is shown to be diphyletic. Cricetomys sp. 1, a separate operational taxonomic unit closely resembling C. emini, occurs in the forest zone of West Africa. An undescribed sister‐species of C. ansorgei, Cricetomys sp. 2, occurs in the forest of Central Africa along the left bank of the Congo River. Cricetomys sp. 3 occurs on the right bank of the Congo River from Cameroon to the Republic of Congo, whereas the true C. emini also occurs on the right bank of the Congo River but appears to be restricted to the Democratic Republic of Congo. Cranial phenotype within the genus tends to conform to ecological zonation (either forest or savannah) rather than to phylogenetic affiliation of the species concerned, suggesting that diversifying selection across environmental gradients could be responsible for biological diversification within the genus.     

Autosomal and mtDNA Markers Affirm the Distinctiveness of Lions in West and Central Africa

The evolutionary history of a species is key for understanding the taxonomy and for the design of effective management strategies for species conservation. The knowledge about the phylogenetic position of the lion (Panthera leo) in West/Central Africa is largely based on mitochondrial markers. Previous studies using mtDNA only have shown this region to hold a distinct evolutionary lineage. In addition, anthropogenic factors have led to a strong decline in West/Central African lion numbers, thus, the conservation value of these populations is particularly high. Here, we investigate whether autosomal markers are concordant with previously described phylogeographic patterns, and confirm the unique position of the West/Central African lion. Analysis of 20 microsatellites and 1,454 bp of the mitochondrial DNA in 16 lion populations representing the entire geographic range of the species found congruence in both types of markers, identifying four clusters: 1) West/Central Africa, 2) East Africa, 3) Southern Africa and 4) India. This is not in line with the current taxonomy, as defined by the IUCN, which only recognizes an African and an Asiatic subspecies. There are no indications that genetic diversity in West/Central Africa lions is lower than in either East or Southern Africa, however, given this genetic distinction and the recent declines of lion numbers in this region, we strongly recommend prioritization of conservation projects in West/Central Africa. As the current taxonomic nomenclature does not reflect the evolutionary history of the lion, we suggest that a taxonomic revision of the lion is warranted.     

Are local patterns of anthropoid primate diversity related to patterns of diversity at a larger scale?

Aims (1) To determine the relationship between local and regional anthropoid primate species richness. (2) To establish the spatial and temporal scale at which the ultimate processes influencing patterns of primate species coexistence operate. Location Continental landmasses of Africa, South America and Asia (India to China, and all islands as far south as New Guinea). Methods The local–regional species richness relationship for anthropoid primates is estimated by regressing local richness against regional richness (independent variable). Local richness is estimated in small, replicate local assemblages sampled in regions that vary in total species richness. A strong linear relationship is taken as evidence that local assemblages are unsaturated and local richness results from proportional sampling of the regional pool. An asymptotic curvilinear relationship is interpreted to reflect saturated communities, where strong biotic interactions limit local richness and local processes structure the species assemblage. As a further test of the assumption of local assemblage saturation, we looked for density compensation in high‐density local primate assemblages. Results The local–regional species richness relationship was linear for Africa and South America, and the slope of the relationship did not differ between the two continents. For Asia, curvilinearity best described the relationship between local and regional richness. Asian primate assemblages appear to be saturated and this is confirmed by density compensation among Asian primates. However, density compensation was also observed among African primates. The apparent assemblage saturation in Asia is not a species–area phenomenon related to the small size of the isolated islands and their forest blocks, since similar low local species richness occurs in large forests on mainland and/or peninsular Asia. Main conclusions In Africa and South America local primate assemblage composition appears to reflect the influence of biogeographic processes operating on regional spatial scales and historical time scales. In Asia the composition of primate assemblages are by‐and‐large subject to ecological constraint operating over a relatively small spatial and temporal scale. The possible local influence of the El Niño Southern Oscillations on the evolution and selection of life‐history characteristics among Asian primates, and in determining local patterns of primate species coexistence, warrants closer inspection.