Contrasting geographic structure in evolutionarily divergent Lake Tanganyika catfishes

Geographic isolation is suggested to be among the most important processes in the generation of cichlid fish diversity in East Africa's Great Lakes, both through isolation by distance and fluctuating connectivity caused by changing lake levels. However, even broad scale phylogeographic patterns are currently unknown in many non‐cichlid littoral taxa from these systems. To begin to address this, we generated restriction‐site‐associated DNA sequence (RADseq) data to investigate phylogeographic structure throughout Lake Tanganyika (LT) in two broadly sympatric rocky shore catfish species from independent evolutionary radiations with differing behaviors: the mouthbrooding claroteine, Lophiobagrus cyclurus, and the brood‐parasite mochokid, Synodontis multipunctatus. Our results indicated contrasting patterns between these species, with strong lake‐wide phylogeographic signal in L. cyclurus including a deep divergence between the northern and southern lake basins. Further structuring of these populations was observed across a heterogeneous habitat over much smaller distances. Strong population growth was observed in L. cyclurus sampled from shallow shorelines, suggesting population growth associated with the colonization of new habitats following lake‐level rises. Conversely, S. multipunctatus, which occupies a broader depth range, showed little phylogeographic structure and lower rates of population growth. Our findings suggest that isolation by distance and/or habitat barriers may play a role in the divergence of non‐cichlid fishes in LT, but this effect varies by species.     

A tale of the nearly tail‐less: the effects of Plio‐Pleistocene climate change on the diversification of the African avian genus Sylvietta

Sylvietta is a broadly distributed group of African species inhabiting a wide range of habitats and presents an interesting opportunity to investigate the historic mechanisms that have impacted the biogeography of African avian species. We collected sequence data from 50 individuals and used model‐based phylogenetic methods, molecular divergence estimates and ancestral area estimates to construct a time‐calibrated phylogeny and estimation of biogeographic history. We estimate a southern African origin for Sylvietta, with an initial divergence splitting the genus into two clades. The first consists of arid‐adapted species, with a southern African origin and subsequent diversification north into Ethiopia–Somalia. The second clade is estimated as having a Congolian forest origin with an eastward pattern of colonization and diversification as a result of Plio‐Pleistocene forest dynamics. Additionally, two members of the genus Sylvietta display interesting patterns of intraspecific diversification. Sylvietta rufescens is an arid‐adapted species inhabiting southern Africa, and we recover two subclades with a divergence dating to the Pleistocene, a unique pattern for avian species which may be explained via isolation in arid habitat fragments in the early Pleistocene. Second, Sylvietta virens, a species endemic to Afro‐tropical forests, is recovered with geographically structured genetic diversification across its broad range, an interesting result given that recent investigations of several avian forest species have found similar and substantial geographically structured genetic diversity relating to Plio‐Pleistocene forest fragmentation. Overall, Plio‐Pleistocene habitat cycling played a significant role in driving diversification in Sylvietta, and this investigation highlights the substantial impact of climate‐driven habitat dynamics on the history of sub‐Saharan species.     

A large-scale phylogeny of Synodontis (Mochokidae,Siluriformes) reveals the influence of geological events on continental diversity during the Cenozoic

To explain the spatial variability of fish taxa at a large scale, two alternative proposals are usually evoked. In recent years, the debate has centred on the relative roles of present and historical processes in shaping biodiversity patterns. In Africa, attempts to understand the processes that determine the large scale distribution of fishes and exploration of historical contingencies have been under-investigated given that most of the phylogenetic studies focus on the history of the Great Lakes. Here, we explore phylogeographic events in the evolutionary history of Synodontis (Mohokidae, Siluriformes) over Africa during the Cenozoic focusing on the putative role of historical processes. We discuss how known geological events together with hydrographical changes contributed to shape Synodontis biogeographical history. Synodontis was chosen on the basis of its high diversity and distribution in Africa: it consists of approximately 120 species that are widely distributed in all hydrographic basins except the Maghreb and South Africa. We propose the most comprehensive phylogeny of this catfish genus. Our results provide support for the ‘hydrogeological’ hypothesis, which proposes that palaeohydrological changes linked with the geological context may have been the cause of diversification of freshwater fish deep in the Tertiary. More precisely, the two main geological structures that participated to shape the hydrographical network in Africa, namely the Central African Shear zone and the East African rift system, appear as strong drivers of Synodontis diversification and evolution.     

Evaluation of the fossil fish‐specific diversity in a chadian continental assemblage: Exploration of morphological continuous variation in Synodontis (Ostariophysi,Siluriformes)

In the fossil record, the quantification of continuous morphological variation has become a central issue when dealing with species identification and speciation. In this context, fossil taxa with living representatives hold great promise, because of the potential to characterise patterns of intraspecific morphological variation in extant species prior to any interpretation in the fossil record. The vast majority of catfish families fulfil this prerequisite, as most of them are represented by extant genera. However, although they constitute a major fish group in terms of distribution, and ecological and taxonomic diversity, the quantitative study of their past morphological variation has been neglected, as fossil specimens are generally identified based on the scarcest remains, that is, complete neurocrania that bear discrete characters. Consequently, a part of freshwater catfish history is unprospected and unknown. In this study, we explored the morphological continuous variation of the humeral plate shape in Synodontis catfishes using Elliptic Fourier Analysis (EFA), and compared extant members and fossil counterparts. We analysed 153 extant specimens of 11 Synodontis species present in the Chad basin, in addition to 23 fossil specimens from the Chadian fossiliferous area of Toros Menalla which is dated around 7 Ma. This highly speciose genus, which is one of the most diversified in Africa, exhibits a rich fossil record with several hundred remains mostly identified as Synodontis sp. The analysis of the outline of the humeral plate reveals that some living morphological types were already represented in the Chad Basin 7 My ago, and allows for the discovery of extinct species. Beside illuminating the complex Neogene evolutionary history of Synodontis, these results underline the interest in the ability of isolated remains to reconstruct a past dynamic history and to validate the relevance of EFA as a tool to explore specific diversity through time. J. Morphol. 277:1486–1496, 2016. © 2016 Wiley Periodicals, Inc.     

Time of diversification in the Cape fauna endemisms,inferred by phylogenetic studies of the genus Iselma (Coleoptera: Meloidae: Eleticinae)

The endemic diversification of the Cape zone fauna and the phylogenetic relationships among the 30 species of the blister beetle genus Iselma are investigated. We analysed morphological, molecular (mtDNA 16S) and combined datasets of characters using a number of approaches (maximum parsimony, maximum likelihood, Bayesian inference analyses). We propose hypotheses of diversification times among taxa from molecular clock analyses. Morphological and molecular analyses produced similar results. According to maximum likelihood molecular studies, radiation within the genus Iselma occurred during the Pliocene and Pleistocene, roughly contemporaneously with the shift in African climate, vegetation and faunal assemblages. Two main lineages, one Namibian and one South African, separated c. 4.9 Ma. Within the South African lineage we identify two groups of endemic species, one in Little Karoo and one that extend towards southern Namaqualand. The remaining South African groups of species are spread through Namaqualand and the southwestern Cape area. These include several endemisms, with different times of diversification during the Pleistocene, probably related in part to glacial cycles. These endemisms are distributed in small areas of the following ecosystems: coastal Strandveld, Succulent Karoo and particularly Fynbos.     

Mitochondrial phylogeny and phylogeography of East African squeaker catfishes (Siluriformes: Synodontis)

Background  

Squeaker catfishes (Pisces, Mochokidae, Synodontis) are widely distributed throughout Africa and inhabit a biogeographic range similar to that of the exceptionally diverse cichlid fishes, including the three East African Great Lakes and their surrounding rivers. Since squeaker catfishes also prefer the same types of habitats as many of the cichlid species, we hypothesized that the East African Synodontis species provide an excellent model group for comparative evolutionary and phylogeographic analyses.     

Biogeography and diversification of Holarctic water striders: Cenozoic temperature variation,habitat shifting and multiple intercontinental dispersals

It is now rare to find a semi‐aquatic organism group with which to vigorously test whether their diversification model and distribution pattern are closely related to the Cenozoic temperature variation. This hypothesis is explored for water striders of the genera Aquarius Schellenberg, Gerris Fabricius and Limnoporus Stål, which comprise a monophyletic clade with primarily Holarctic distribution. We sample almost 90% of the currently recognized Aquarius , Gerris and Limnoporus species. Five DNA fragments from 62 species are used to reconstruct a phylogram. Divergence time is estimated using Bayesian relaxed‐clock method and three fossil calibrations. We investigate diversification dynamics, biogeography and ancestral state reconstruction by using maximum‐likelihood, Bayesian and parsimony approaches. Our results showed that the crown of the three genera originated and underwent an initial diversification in Asia at 72 Ma (HPD: 59–86 Ma) in the Late Cretaceous, subsequently expanding into other regions via dispersal. The Bering Land Bridge was the major migration route between Eurasia and North America but was interrupted before the early Oligocene (34 Ma). Ancestors most likely used lentic habitats, and a minimum of two independent shifts to lotic habitats occurred in the initial diversification. Cenozoic temperature variation regulated the evolutionary history of Holarctic water striders of the genera Aquarius , Gerris and Limnoporus . Temperature warming during Stage I (52–66 Ma) was associated with the disappearance of shallow lentic habitats; this phenomenon forced certain lentic lineages to colonize new lotic habitats and promoted the diversification of lineages. Temperature cooling during Stage II (after 34 Ma) was associated with the fragmentation of water habitats of the ‘mixed‐mesophytic’ belt, resulting in the extinction of historical taxa and influencing close lineages that shaped the present disjunct Eurasian–North American distribution.     

Diversification across major biogeographic breaks in the African Shining/Square‐tailed Drongos complex (Passeriformes: Dicruridae)

Surprisingly, little is known about the extent of genetic structure within widely distributed and polytypic African species that are not restricted to a particular habitat type. The few studies that have been conducted suggested that speciation among African vertebrates may be intrinsically tied to habitat and the dynamic nature of biome boundaries. In the present study, we assessed the geographic structure of genetic variation across two sister‐species of drongos, the Square‐tailed Drongo (Dicrurus ludwigii) and the Shining Drongo (D. atripennis), that are distributed across multiple sub‐Saharan biogeographic regions and habitat types. Our results indicate that D. ludwigii consists of two strongly divergent lineages, corresponding to an eastern–southern lineage and a central‐western lineage. Furthermore, the central‐western lineage may be more closely related to D. atripennis, a species restricted to the Guineo‐Congolian forest block, and it should therefore be ranked as a separate species from the eastern–southern lineage. Genetic structure is also recovered within the three primary lineages of the D. atripennis–D. ludwigii complex, suggesting that the true species diversity still remains underestimated. Additional sampling and data are required to resolve the taxonomic status of several further populations. Overall, our results suggest the occurrence of complex diversification patterns across habitat types and biogeographic regions in sub‐Saharan Africa birds.     

Mastacembelid eels support Lake Tanganyika as an evolutionary hotspot of diversification

Background  

Lake Tanganyika (LT) is the oldest of the African Rift Lakes and is one of the richest freshwater ecosystems on Earth, with high levels of faunal diversity and endemism. The endemic species flocks that occur in this lake, such as cichlid fishes, gastropods, catfish and crabs, provide unique comparative systems for the study of patterns and processes of speciation. Mastacembelid eels (Teleostei: Mastacembelidae) are a predominately riverine family of freshwater fish, occurring across Africa and Asia, but which also form a small species flock in LT.     

Biogeographical contingency and the evolution of tropical anchovies (genus Cetengraulis) from temperate anchovies (genus Engraulis)

Aim Similar regimes of selection in different geographical settings can deterministically produce similar adaptive morphologies. We tested the hypothesis that the evolutionary trajectories of fish in upwelling zones can be altered by biogeographic contingencies in the biological and physical environment. Location Eastern Pacific and western Atlantic oceans. Methods We estimated phylogenetic relationships among eastern Pacific temperate anchovies (genus Engraulis) and tropical anchovies (genus Cetengraulis) with neighbour‐joining and Bayesian tree analysis of a 521‐bp segment of mitochondrial DNA cytochrome b. Available sequences for five additional engraulid taxa were included to establish polarity of the tree. Bayesian estimates (BEAST) of time to most recent common ancestor (TMRCA) for the nodes in the phylogeny were calibrated with divergence between Cetengraulis edentulus and Cetengraulis mysticetus precipitated by the rise of the Panama Isthmus 2.8–3.2 Ma. Results Neighbour‐joining and Bayesian trees indicate that South American Engraulis anchoita (Argentina) and Engraulis ringens (Chile) together are basal sister taxa to the California anchovy (Engraulis mordax) and Old World anchovies (Engraulis japonicas, Engraulis australis, Engraulis capensis and Engraulis encrasicolus). The two tropical species of Cetengraulis are sister‐taxa to Californian E. mordax, even though their phenotypes and ecologies differ markedly. A relaxed molecular clock indicates a TMRCA between Californian E. mordax and Cetengraulis at about 4.2 Ma (3.0–6.3 Ma 95% highest probability density). Main conclusions The TMRCA between the California anchovy, E. mordax, and tropical Cetengraulis coincides with the formation of the Gulf of California, which provided opportunities for allopatric isolation during climate oscillations. Mid‐Pliocene warming (3.1–2.9 Ma) may have trapped ancestors of Cetengraulis in the Gulf of California, where they evolved digestive tract morphologies to exploit inshore tropical habitats with low plankton productivities. While populations of several other temperate fishes have become isolated in the Gulf of California, few of these derived species show strong adaptive shifts from temperate sister taxa or range expansions into the tropical provinces of the western Atlantic and eastern Pacific.     

Ancient forest fragmentation or recent radiation? Testing refugial speciation models in chameleons within an African biodiversity hotspot

Aim East Africa is one of the most biologically diverse regions, especially in terms of endemism and species richness. Hypotheses put forward to explain this high diversity invoke a role for forest refugia through: (1) accumulation of new species due to radiation within refugial habitats, or (2) retention of older palaeoendemic species in stable refugia. We tested these alternative hypotheses using data for a diverse genus of East African forest chameleons, Kinyongia. Location East Africa. Methods We constructed a dated phylogeny for Kinyongia using one nuclear and two mitochondrial markers. We identified areas of high phylogenetic diversity (PD) and evolutionary diversity (ED), and mapped ancestral areas to ascertain whether lineage diversification could best be explained by vicariance or dispersal. Results Vicariance best explains the present biogeographic patterns, with divergence between three major Kinyongia clades (Albertine Rift, southern Eastern Arc, northern Eastern Arc) in the early Miocene/Oligocene (> 20 Ma). Lineage diversification within these clades pre‐dates the Pliocene (> 6 Ma). These dates are much older than the Plio‐Pleistocene climatic shifts associated with cladogenesis in other East African taxa (e.g. birds), and instead point to a scenario whereby palaeoendemics are retained in refugia, rather than more recent radiations within refugia. Estimates of PD show that diversity was highest in the Uluguru, Nguru and East Usambara Mountains and several lineages (from Mount Kenya, South Pare and the Uluguru Mountains) stand out as being evolutionarily distinct as a result of isolation in forest refugia. PD was lower than expected by chance, suggesting that the phylogenetic signal is influenced by an unusually low number of extant lineages with long branch lengths, which is probably due to the retention of palaeoendemic lineages. Main conclusions The biogeographic patterns associated with Kinyongia are the result of long evolutionary histories in isolation. The phylogeny is dominated by ancient lineages whose origins date back to the early Miocene/Oligocene as a result of continental wide forest fragmentation and contraction due to long term climatic changes in Africa. The maintenance of palaeoendemic lineages in refugia has contributed substantially to the remarkably high biodiversity of East Africa.     

Cryptic species and co‐diversification in sand scorpions from the Karakum and Kyzylkum deserts of Central Asia

Little is known about species diversification within the deserts of Central Asia. For example, the degree of lineage divergence and timing of population differentiation, as well as potential biogeographic barriers driving diversification, are nearly unknown. Here, we analysed a multi‐locus data set for a widespread sand scorpion (Mesobuthus gorelovi) to evaluate cryptic species diversity and phylogeographic patterns across the Karakum and Kyzylkum deserts. We also combined these data with previously published sequence data to test for a signal of co‐diversification. A consensus species delimitation approach indicated that the widespread M. gorelovi is likely composed of up to five distinct species that began to diversify at the Miocene–Pliocene boundary. We observed shared patterns of lineage divergence across the Amu Darya River region in three scorpion taxa and found support for a shared history of assemblage diversification across this biogeographic barrier. Thus, major river systems appear to facilitate diversification among desert scorpions.     

Area and the rapid radiation of Hawaiian Bidens (Asteraceae)

Aim To estimate the rate of adaptive radiation of endemic Hawaiian Bidens and to compare their diversification rates with those of other plants in Hawaii and elsewhere with rapid rates of radiation. Location Hawaii. Methods Fifty‐nine samples representing all 19 Hawaiian species, six Hawaiian subspecies, two Hawaiian hybrids and an additional two Central American and two African Bidens species had their DNA extracted, amplified by polymerase chain reaction and sequenced for four chloroplast and two nuclear loci, resulting in a total of approximately 5400 base pairs per individual. Internal transcribed spacer sequences for additional outgroup taxa, including 13 non‐Hawaiian Bidens, were obtained from GenBank. Phylogenetic relationships were assessed by maximum likelihood and Bayesian inference. The age of the most recent common ancestor and diversification rates of Hawaiian Bidens were estimated using the methods of previously published studies to allow for direct comparison with other studies. Calculations were made on a per‐unit‐area basis. Results We estimate the age of the Hawaiian clade to be 1.3–3.1 million years old, with an estimated diversification rate of 0.3–2.3 species/million years and 4.8 × 10^?5 to 1.3 × 10^?4 species Myr^?1 km^?2. Bidens species are found in Europe, Africa, Asia and North and South America, but the Hawaiian species have greater diversity of growth form, floral morphology, dispersal mode and habitat type than observed in the rest of the genus world‐wide. Despite this diversity, we found little genetic differentiation among the Hawaiian species. This is similar to the results from other molecular studies on Hawaiian plant taxa, including others with great morphological variability (e.g. silverswords, lobeliads and mints). Main conclusions On a per‐unit‐area basis, Hawaiian Bidens have among the highest rates of speciation for plant radiations documented to date. The rapid diversification within such a small area was probably facilitated by the habitat diversity of the Hawaiian Islands and the adaptive loss of dispersal potential. Our findings point to the need to consider the spatial context of diversification – specifically, the relative scale of habitable area, environmental heterogeneity and dispersal ability – to understand the rate and extent of adaptive radiation.     

A long‐standing Pleistocene refugium in southern Africa and a mosaic of refugia in East Africa: insights from mtDNA and the common eland antelope

Aim Previous genetic studies of African savanna ungulates have indicated Pleistocene refugial areas in East and southern Africa, and recent palynological, palaeovegetation and fossil studies have suggested the presence of a long‐standing refugium in the south and a mosaic of refugia in the east. Phylogeographic analysis of the common eland antelope, Taurotragus oryx (Bovidae), was used to assess these hypotheses and the existence of genetic signatures of Pleistocene climate change. Location The sub‐Saharan savanna biome of East and southern Africa. Methods Mitochondrial DNA control‐region fragments (414 bp) from 122 individuals of common eland were analysed to elucidate the phylogeography, genetic diversity, spatial population structuring, historical migration and demographic history of the species. The phylogeographic split among major genetic lineages was dated using Bayesian coalescent‐based methods and a calibrated fossil root of 1.6 Ma for the split between the common eland and the giant eland, Taurotragus derbianus. Results Two major phylogeographic lineages comprising East and southern African localities, respectively, were separated by a net nucleotide distance of 4.7%. A third intermediate lineage comprised only three haplotypes, from Zimbabwe in southern Africa. The estimated mutation rate of 0.097 Myr^?1 revealed a more recent common ancestor for the eastern lineage (0.21 Ma; 0.07–0.37) than for the southern lineage (0.35 Ma; 0.10–0.62). Compared with the latter, the eastern lineage showed pronounced geographic structuring, lower overall nucleotide diversity, higher population differentiation, and isolation‐by‐distance among populations. Main conclusions The data support the hypothesis of Pleistocene refugia occurring in East and southern Africa. In agreement with palynological, palaeovegetation and fossil studies, our data strongly support the presence of a longer‐standing population in the south and a mosaic of Pleistocene refugia in the east, verifying the efficacy of genetic tools in addressing such questions. The more recent origin of the common eland inhabiting East Africa could result from colonization following extinction from the region. Only two other dated African ungulate phylogenies have been published, applying different methods, and the similarity of dates obtained from the three distinct approaches indicates a significant event c. 200 ka, which left a strong genetic signature across a range of ungulate taxa.     

A morphological key for the identification of southern African Synodontis species Cuvier, 1816 (Teleostei: Mochokidae)

The identification of the southern African Synodontis species is hampered by variable and overlapping morphological characteristics such as colour, pigmentation patterns and morphometric ratios. Species are often misidentified due to the complicated nature of the present identification keys. The morphological key proposed in this note uses simplified characters including the shape of the humeral process, size of the outer mandibular barbel, teeth rows, position of the mouth, basal membrane of the maxillary barbel and length of the maxillary barbels, plus the natural distribution range of certain species to facilitate positive identification of southern African Synodontis specimens.     

Speciation with gene flow in whiptail lizards from a Neotropical xeric biome

Two main hypotheses have been proposed to explain the diversification of the Caatinga biota. The riverine barrier hypothesis (RBH) claims that the São Francisco River (SFR) is a major biogeographic barrier to gene flow. The Pleistocene climatic fluctuation hypothesis (PCH) states that gene flow, geographic genetic structure and demographic signatures on endemic Caatinga taxa were influenced by Quaternary climate fluctuation cycles. Herein, we analyse genetic diversity and structure, phylogeographic history, and diversification of a widespread Caatinga lizard (Cnemidophorus ocellifer) based on large geographical sampling for multiple loci to test the predictions derived from the RBH and PCH. We inferred two well‐delimited lineages (Northeast and Southwest) that have diverged along the Cerrado–Caatinga border during the Mid‐Late Miocene (6–14 Ma) despite the presence of gene flow. We reject both major hypotheses proposed to explain diversification in the Caatinga. Surprisingly, our results revealed a striking complex diversification pattern where the Northeast lineage originated as a founder effect from a few individuals located along the edge of the Southwest lineage that eventually expanded throughout the Caatinga. The Southwest lineage is more diverse, older and associated with the Cerrado–Caatinga boundaries. Finally, we suggest that C. ocellifer from the Caatinga is composed of two distinct species. Our data support speciation in the presence of gene flow and highlight the role of environmental gradients in the diversification process.     

The ancient Britons: groundwater fauna survived extreme climate change over tens of millions of years across NW Europe

Global climate changes during the Cenozoic (65.5–0 Ma) caused major biological range shifts and extinctions. In northern Europe, for example, a pattern of few endemics and the dominance of wide‐ranging species is thought to have been determined by the Pleistocene (2.59–0.01 Ma) glaciations. This study, in contrast, reveals an ancient subsurface fauna endemic to Britain and Ireland. Using a Bayesian phylogenetic approach, we found that two species of stygobitic invertebrates (genus Niphargus) have not only survived the entire Pleistocene in refugia but have persisted for at least 19.5 million years. Other Niphargus species form distinct cryptic taxa that diverged from their nearest continental relative between 5.6 and 1.0 Ma. The study also reveals an unusual biogeographical pattern in the Niphargus genus. It originated in north‐west Europe approximately 87 Ma and underwent a gradual range expansion. Phylogenetic diversity and species age are highest in north‐west Europe, suggesting resilience to extreme climate change and strongly contrasting the patterns seen in surface fauna. However, species diversity is highest in south‐east Europe, indicating that once the genus spread to these areas (approximately 25 Ma), geomorphological and climatic conditions enabled much higher diversification. Our study highlights that groundwater ecosystems provide an important contribution to biodiversity and offers insight into the interactions between biological and climatic processes.     

Biogeographic barriers in south‐eastern Australia drive phylogeographic divergence in the garden skink,Lampropholis guichenoti

Aim To investigate the impact of climatic oscillations and recognized biogeographic barriers on the evolutionary history of the garden skink (Lampropholis guichenoti), a common and widespread vertebrate in south‐eastern Australia. Location South‐eastern Australia. Methods Sequence data were obtained from the ND4 mitochondrial gene for 123 individuals from 64 populations across the entire distribution of the garden skink. A range of phylogenetic (maximum likelihood, Bayesian) and phylogeographic analyses (genetic diversity, Tajima’s D, Φ_ST, mismatch distribution) were conducted to examine the evolutionary history and diversification of the garden skink. Results A deep phylogeographic break (c. 14%), estimated to have occurred in the mid–late Miocene, was found between ‘northern’ and ‘southern’ populations across the Hunter Valley in northern New South Wales. Divergences among the geographically structured clades within the ‘northern’ (five clades) and ‘southern’ (seven clades) lineages occurred during the Pliocene, with the location of the major breaks corresponding to the recognized biogeographic barriers in south‐eastern Australia. Main conclusions Climatic fluctuations and the presence of several elevational and habitat barriers in south‐eastern Australia appear to be responsible for the diversification of the garden skink over the last 10 Myr. Further molecular and morphological work will be required to determine whether the two genetic lineages represent distinct species.     

Deep divergence among mitochondrial lineages in African jackals

Recently, molecular analyses revealed that African and Eurasian golden jackals are distinct species. This finding suggests re‐investigation of the phylogenetic relationships and taxonomy of other African members of the Canidae. Here, we provide a study on the phylogenetic relationship between populations of African jackals Lupulella mesomelas and L. adusta inferred from 962 bp of the mitochondrial cytochrome b (cytb) gene. As expected from its disjunct distribution, with one population in eastern Africa and the other one in southern Africa, we found two mitochondrial lineages within L. mesomelas, which diverged about 2.5 million years ago (Ma). In contrast, in L. adusta with its more continuous distribution in sub‐Saharan Africa, we found only a shallower genetic diversification, with the exception of the West African population, which diverged around 1.4 Ma from the Central and East African populations. Both divergence ages are older than, for example the 1.1–0.9 million years between the grey wolf Canis lupus and the African golden wolf C. lupaster. One taxonomic implication of our findings might be that the two L. mesomelas populations warrant species status. However, genome‐wide data with adequate geographical sampling are needed to substantiate our results.     

‘After Africa’: the evolutionary history and systematics of the genus Charaxes Ochsenheimer (Lepidoptera: Nymphalidae) in the Indo‐Pacific region

The predominantly Afrotropical genus Charaxes is represented by 31 known species outside of Africa (excluding subgenus Polyura Billberg). We explored the biogeographic history of the genus using every known non‐African species, with several African species as outgroup taxa. A phylogenetic hypothesis is proposed, based on molecular characters of the mitochondrial genes cytochrome oxidase subunit I (COI) and NADH dehydrogenase 5 (ND5), and the nuclear wingless gene. Phylogenetic analyses based on maximum parsimony and Bayesian inference of the combined dataset implies that the Indo‐Pacific Charaxes form a monophyletic assemblage, with the exception of Charaxes solon Fabricius. Eight major lineages are recognized in the Indo‐Pacific, here designated the solon (+African), elwesi, harmodius, amycus, mars, eurialus, latona, nitebis, and bernardus clades. Species group relationships are concordant with morphology and, based on the phylogeny, we present the first systematic appraisal and classification of all non‐African species. A biogeographical analysis reveals that, after the genus originated in Africa, the evolutionary history of Charaxes in the Indo‐Pacific, in particular Wallacea, may be correlated with the inferred geological and climatic history of the region. We propose that Wallacea was the area of origin of all Charaxes (excluding C. solon) occurring to the east of Wallace's [1863] Line. The earliest Indo‐Pacific lineages appear to have diverged subsequent to the initial fragmentation of a palaeo‐continent approximately 13 million years ago. Further diversification in Indo‐Pacific Charaxes appears primarily related to climatic changes during the Pliocene and possibly as recently as the Pleistocene. Although both dispersal and vicariance have played important roles in the evolution of the genus within the region, the latter has been particularly responsible for diversification of Charaxes in Wallacea. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 457–481.