Anagenetic evolution in island plants

Aim  Plants in islands have often evolved through adaptive radiation, providing the classical model of evolution of closely related species each with strikingly different morphological and ecological features and with low levels of genetic divergence. We emphasize the importance of an alternative (anagenetic) model of evolution, whereby a single island endemic evolves from a progenitor and slowly builds up genetic variation through time.
Location  Continental and oceanic islands.
Methods  We surveyed 2640 endemic angiosperm species in 13 island systems of the world, both oceanic and continental, for anagenetic and cladogenetic patterns of speciation. Genetic data were evaluated from a progenitor and derivative species pair in Ullung Island, Korea, and Japan.
Results  We show that the anagenetic model of evolution is much more important in oceanic islands than previously believed, accounting for levels of endemic specific diversity from 7% in the Hawaiian Islands to 88% in Ullung Island, Korea, with a mean for all islands of 25%. Examination of an anagenetically derived endemic species in Ullung Island reveals genetic (amplified fragment length polymorphism) variation equal or nearly equal to that of its continental progenitor.
Main conclusions  We hypothesize that, during anagenetic speciation, initial founder populations proliferate, and then accumulate genetic variation slowly through time by mutation and recombination in a relatively uniform environment, with drift and/or selection yielding genetic and morphological divergence sufficient for the recognition of new species. Low-elevation islands with low habitat heterogeneity are highly correlated with high levels of anagenetic evolution, allowing prediction of levels of the two models of evolution from these data alone. Both anagenetic and adaptive radiation models of speciation are needed to explain the observed levels of specific and genetic diversity in oceanic islands.     

Evolutionary ecology and radiation of Hawaiian passerine birds

The Hawaiian islands contain the most spectacular variety of landbirds ever discovered on remote oceanic islands. The Hawaiian honeycreepers, having evolved from a presumably single founding species of cardueline finch, comprise most of this avifauna. Birds from at least three other families of passerines and five families of non-passerines also radiated in Hawaii. Recent discoveries of a fossil avifauna indicate that most radiations were more extensive than previously thought. Classical analysis of the radiation of Hawaiian birds, especially the honeycreepers, focused on characters related to acquisition of food. Recent studies of bill size and shape in relation to food resources, and of foraging mode in relation to interspecific competitors, provide models of how divergence in diet and/or bill morphology might have evolved. Studies of geographic variation among subspecies on different islands and among populations within islands have revealed extensive divergence in characters such as sexual chromatism, nest sites and nest morphology.     

Labile ecotypes accompany rapid cladogenesis in an adaptive radiation of Mandarina (Bradybaenidae) land snails

The endemic land snail genus Mandarina of the oceanic Bonin Islands shows exceptionally diverse morphological and ecological traits. Previous studies have already provided evidence that speciation on different islands of the three main archipelagos was such that similar ecotypes evolved independently in different lineages and islands. Here we present data to show that the same species can have different ecotypes. As most of the characters involved are inherited, then variation between ecotypes must represent genetic differences between populations. We then show that the radiation on the Bonin Islands is derived from a single colonization event, and use a mitochondrial phylogeny to provide evidence for a burst of cladogenesis soon after colonization. As divergent selection has previously been implicated in causing differences between Mandarina species, and theory predicts that most of the speciation should have taken place early in their history, then the study adds to the evidence for an adaptive radiation by ecological speciation in Mandarina . However, while the diversity of ecotypes present at each site is dependent on the regime of natural selection and competition, geography still must have an important role.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 269–282.     

Rapid, independent evolution of flightlessness in four species of Pacific Island rails (Rallidae): an analysis based on mitochondrial sequence data

Flightless rails were once ubiquitous in the avifauna of Pacific oceanic islands. Most species have become extinct since human colonization of islands began about 2000 years ago. In this study, we use mitochondrial sequence data to estimate the phylogenetic relationships and ages of four species of flightless insular rails in the genus Porzana : palmeri , from Laysan Island in the Hawaiian archipelago; sandwichensis , from the island of Hawaii; monasa , from Kosrae Island in Micronesia; and atra , from Henderson Island in the Pitcairn group. Although all four species survived into historic times, all but atra are now extinct. The optimal trees show that palmeri is descended from Porzana pusilla , a volant crake distributed widely throughout the Old World. Porzana sandwichensis , P. monasa , and P. atra are each descended from the lineage leading to P. tabuensis , a volant rail widespread in northern and eastern Australia and on islands north to Micronesia and the Philippines and east through Polynesia. Loss of flight appears to have evolved rapidly in these insular rails, based on both sequence divergence values and data on the ages of the islands. In the case of the Laysan Rail ( palmeri ), divergences including loss of flight probably evolved in less than 125,000 years .     

MULTIPLE COLONIZATIONS OF ASPLENIUM ADIANTUM-NIGRUM ONTO THE HAWAIIAN ARCHIPELAGO

The extreme isolation and mid-Pacific origin of the Hawaiian archipelago has ensured that all indigenous organisms have arrived via long-distance dispersal or have evolved from successfully colonizing species. Although this isolation has also produced high rates of species endemism in angiosperms (89% or more), that rate in pteridophytes is considerably less (76%). The ratio of native species to the estimated number of original successful colonizing species in angiosperms (3.4) is more than double that for pteridophytes (1.6). One possible explanation for the lower speciation rate in pteridophytes is that populations of these species are more likely to experience interpopulational gene flow because of the great vagility of their wind-dispersed spores. We conducted isozymic surveys of populations from the island of Hawaii of the indigenous allotetraploid species Asplenium adiantum-nigrum, putatively derived from two strictly European diploid taxa. Our data support multiple hybrid origins for the populations surveyed, with a minimum of 3, and possibly as many as 17, discrete hybridization events having produced the genetic diversity observed. Since the parental taxa are not found in Hawaii, each hybrid lineage must have arrived in the archipelago independently of the others. Similar long-distance, repeated dispersal events may be occurring between insular and noninsular populations of other native pteridophytes in Hawaii and in other insular regions of the world, thus contributing to the relatively low rates of speciation and insular endemism in this ancient group of plants.     

A general dynamic theory of oceanic island biogeography

Aim MacArthur and Wilson’s dynamic equilibrium model of island biogeography provides a powerful framework for understanding the ecological processes acting on insular populations. However, their model is known to be less successful when applied to systems and processes operating on evolutionary and geological timescales. Here, we present a general dynamic model (GDM) of oceanic island biogeography that aims to provide a general explanation of biodiversity patterns through describing the relationships between fundamental biogeographical processes – speciation, immigration, extinction – through time and in relation to island ontogeny. Location Analyses are presented for the Azores, Canaries, Galápagos, Marquesas and Hawaii. Methods We develop a theoretical argument from first principles using a series of graphical models to convey key properties and mechanisms involved in the GDM. Based on the premises (1) that emergent properties of island biotas are a function of rates of immigration, speciation and extinction, (2) that evolutionary dynamics predominate in large, remote islands, and (3) that oceanic islands are relatively short‐lived landmasses showing a characteristic humped trend in carrying capacity (via island area, topographic variation, etc.) over their life span, we derive a series of predictions concerning biotic properties of oceanic islands. We test a subset of these predictions using regression analyses based largely on data sets for native species and single‐island endemics (SIEs) for particular taxa from each archipelago, and using maximum island age estimates from the literature. The empirical analyses test the power of a simple model of diversity derived from the GDM: the log(Area) + Time + Time² model (ATT²), relative to other simpler time and area models, using several diversity metrics. Results The ATT² model provides a more satisfactory explanation than the alternative models evaluated (for example the standard diversity–area models) in that it fits a higher proportion of the data sets tested, although it is not always the most parsimonious solution. Main conclusions The theoretical model developed herein is based on the key dynamic biological processes (migration, speciation, extinction) combined with a simple but general representation of the life cycle of oceanic islands, providing a framework for explaining patterns of biodiversity, endemism and diversification on a range of oceanic archipelagos. The properties and predictions derived from the model are shown to be broadly supported (1) by the empirical analyses presented, and (2) with reference to previous phylogenetic, ecological and geological studies.     

Mating asymmetry and the direction of evolution in the Hawaiian cricket genus Laupala

Based on studies from native Hawaiian Drosophila, a model was proposed to explain sexual isolation and mating asymmetry, from which one could potentially infer the 'direction of evolution'. We examined sexual isolation between allopatric cricket species of the genus Laupala, another endemic Hawaiian insect with an elaborate mating system, to begin to explore the nature of sexual isolation and mating asymmetry in closely related Hawaiian organisms. We studied sexual isolation and mating asymmetry in two contrasts. First, an inter-island comparison, including L. makaio from the older island of Maui and L. paranigra from the younger island of Hawaii, and second, an intra-island (Hawaii) comparison, including L. nigra from the older volcano of Mauna Kea and L. paranigra with a primary distribution on the younger volcanoes of Mauna Loa and Kilauea. We used a 'no-choice' experimental design, pairing individual males and females in homospecific or heterospecific combinations. Several behavioural aspects of courtship (proportion of male singing, latency to male singing, production of spermatophores and courtship initiation speed) were quantified as well as the success or failure of matings. We demonstrate asymmetry in sexual isolation between reciprocal combinations of L. makaio and L. paranigra. This result is examined in light of the differences in courtship behaviour manifest in the experiments with these two species. We did not find evidence of asymmetry in sexual isolation between L. nigra and L. paranigra, although differences in courtship initiation speed were evident between reciprocal combinations of these two species. In addition to the geological argument that species on older islands and older volcanoes give rise to species on younger islands and younger volcanoes, we discuss phylogenetic evidence consistent with these biogeographic hypotheses of relationships among the focal taxa. The patterns of asymmetrical sexual isolation and mating asymmetry are consistent with those found in the native Hawaiian Drosophila.     

Molecular phylogeny and divergence times of drosophilid species

The phylogenetic relationships and divergence times of 39 drosophilid species were studied by using the coding region of the Adh gene. Four genera--Scaptodrosophila, Zaprionus, Drosophila, and Scaptomyza (from Hawaii)--and three Drosophila subgenera--Drosophila, Engiscaptomyza, and Sophophora--were included. After conducting statistical analyses of the nucleotide sequences of the Adh, Adhr (Adh-related gene), and nuclear rRNA genes and a 905-bp segment of mitochondrial DNA, we used Scaptodrosophila as the outgroup. The phylogenetic tree obtained showed that the first major division of drosophilid species occurs between subgenus Sophophora (genus Drosophila) and the group including subgenera Drosophila and Engiscaptomyza plus the genera Zaprionus and Scaptomyza. Subgenus Sophophora is then divided into D. willistoni and the clade of D. obscura and D. melanogaster species groups. In the other major drosophilid group, Zaprionus first separates from the other species, and then D. immigrans leaves the remaining group of species. This remaining group then splits into the D. repleta group and the Hawaiian drosophilid cluster (Hawaiian Drosophila, Engiscaptomyza, and Scaptomyza). Engiscaptomyza and Scaptomyza are tightly clustered. Each of the D. repleta, D. obscura, and D. melanogaster groups is monophyletic. The splitting of subgenera Drosophila and Sophophora apparently occurred about 40 Mya, whereas the D. repleta group and the Hawaiian drosophilid cluster separated about 32 Mya. By contrast, the splitting of Engiscaptomyza and Scaptomyza occurred only about 11 Mya, suggesting that Scaptomyza experienced a rapid morphological evolution. The D. obscura and D. melanogaster groups apparently diverged about 25 Mya. Many of the D. repleta group species studied here have two functional Adh genes (Adh-1 and Adh-2), and these duplicated genes can be explained by two duplication events.      

Allozyme diversity and the evolution ofSymplocos (Symplocaceae) on the Bonin (Ogasawara) Islands

To study the origin and speciation of plants in oceanic islands, electrophoretic analyses have been done on three endemic species ofSymplocos in the Bonin Islands as well as on three other species;S. kuroki, S. nakaharae andS. tanakae which are considered to be closely related to the Bonin endemics. There occur three species:S. kawakamii, S. pergracilis andS. boninensis in Bonin. The genusSymplocos is one which is considered to be diversified in the Bonin Islands. Seven enzyme systems presumed to be encoded by 18 loci were examined. The genetic diversity was low in the island species, as reported in some oceanic island plants of Hawaii and the Bonin Islands. The three endemics share high genetic identities and they clustered together in the tree drawn by the UPGMA method, suggesting that they are a monophyletic group, that is, they result from a single introduction.     

Factors driving adaptive radiation in plants of oceanic islands: a case study from the Juan Fernández Archipelago

Adaptive radiation is a common evolutionary phenomenon in oceanic islands. From one successful immigrant population, dispersal into different island environments and directional selection can rapidly yield a series of morphologically distinct species, each adapted to its own particular environment. Not all island immigrants, however, follow this evolutionary pathway. Others successfully arrive and establish viable populations, but they remain in the same ecological zone and only slowly diverge over millions of years. This transformational speciation, or anagenesis, is also common in oceanic archipelagos. The critical question is why do some groups radiate adaptively and others not? The Juan Fernández Islands contain 105 endemic taxa of angiosperms, 49% of which have originated by adaptive radiation (cladogenesis) and 51% by anagenesis, hence providing an opportunity to examine characteristics of taxa that have undergone both types of speciation in the same general island environment. Life form, dispersal mode, and total number of species in progenitors (genera) of endemic angiosperms in the archipelago were investigated from literature sources and compared with modes of speciation (cladogenesis vs. anagenesis). It is suggested that immigrants tending to undergo adaptive radiation are herbaceous perennial herbs, with leaky self-incompatible breeding systems, good intra-island dispersal capabilities, and flexible structural and physiological systems. Perhaps more importantly, the progenitors of adaptively radiated groups in islands are those that have already been successful in adaptations to different environments in source areas, and which have also undergone eco-geographic speciation. Evolutionary success via adaptive radiation in oceanic islands, therefore, is less a novel feature of island lineages but rather a continuation of tendency for successful adaptive speciation in lineages of continental source regions.     

Climate drives community‐wide divergence within species over a limited spatial scale: evidence from an oceanic island

Geographic isolation substantially contributes to species endemism on oceanic islands when speciation involves the colonisation of a new island. However, less is understood about the drivers of speciation within islands. What is lacking is a general understanding of the geographic scale of gene flow limitation within islands, and thus the spatial scale and drivers of geographical speciation within insular contexts. Using a community of beetle species, we show that when dispersal ability and climate tolerance are restricted, microclimatic variation over distances of only a few kilometres can maintain strong geographic isolation extending back several millions of years. Further to this, we demonstrate congruent diversification with gene flow across species, mediated by Quaternary climate oscillations that have facilitated a dynamic of isolation and secondary contact. The unprecedented scale of parallel species responses to a common environmental driver for evolutionary change has profound consequences for understanding past and future species responses to climate variation.     

A generalized model of island biogeography

MacArthur and Wilson’s equilibrium theory is one of the most influential theories in ecology. Although evolution on islands is to be important to island biodiversity, speciation has not been well integrated into island biogeography models. By incorporating speciation and factors influencing it into the MacArthur-Wilson model, we propose a generalized model unifying ecological and evolutionary processes and island features. Intra-island speciation may play an important role in both island species richness and endemism, and the contribution of speciation to local species diversity may eventually be greater than that of immigration under certain conditions. Those conditions are related to the per species speciation rate, per species extinction rate, and island features, and they are independent of immigration rate. The model predicts that large islands will have a high, though not the highest, proportional endemism when other parameters are fixed. Based on the generalized model, changes in species richness and endemism on an oceanic island over time were predicted to be similar to empirical observations. Our model provides an ideal starting point for re-evaluating the role of speciation and re-analyzing available data on island species diversity, especially those biased by the MacArthur-Wilson model.     

Remarkable new evidence for island radiation in birds

If island biogeography has a sweet spot, it's where islands generate their own species diversity rather than merely taking on mainland immigrants. In birds and other highly dispersive taxa, however, this 'zone of radiation', may be vanishingly small. Darwin's finches and Hawaiian Honeycreepers are among only a handful of examples of island radiation in birds (Price 2008), suggesting that winged powers of dispersal make sufficient isolation from mainland colonists unlikely, while also hindering speciation within and among isolated islands. Nevertheless, two studies in this issue of Molecular Ecology join a string of other recent analyses suggesting that island radiation in birds remains under-appreciated (see also Moyle et al. 2009; Kisel & Barraclough 2010; Rosindell & Phillimore 2011). Melo et al. (2011) use a phylogenetic analysis of white-eyes on islands in the Gulf of Guinea to identify two previously overlooked island radiations, and reveal replicated adaptive divergence on islands where species occur in pairs. Sly et al. (2011), meanwhile, consider possible explanations for speciation and geographic differentiation within a large island, and find the same type of oceanic barriers that are critical to bird speciation across archipelagos may also contribute to divergence that appears to have occurred within a single island.     

Quantifying island isolation – insights from global patterns of insular plant species richness

Isolation is a driving factor of species richness and other island community attributes. Most empirical studies have investigated the effect of isolation measured as distance to the nearest continent. Here we expanded this perspective by comparing the explanatory power of seventeen isolation metrics in sixty‐eight variations for vascular plant species richness on 453 islands worldwide. Our objectives were to identify ecologically meaningful metrics and to quantify their relative importance for species richness in a globally representative data set. We considered the distances to the nearest mainland and to other islands, stepping stone distances, the area of surrounding landmasses, prevailing wind and ocean currents and climatic similarity between source and target areas. These factors are closely linked to colonization and maintenance of plant species richness on islands. We tested the metrics in spatial multi‐predictor models accounting for area, climate, topography and island geology. Besides area, isolation was the second most important factor determining species richness on the studied islands. A model including the proportion of surrounding land area as the isolation metric had the highest predictive power, explaining 86.1% of the variation. Distances to large islands, stepping stone distances and distances to climatically similar landmasses performed slightly better than distance to the nearest mainland. The effect of isolation was weaker for large islands suggesting that speciation counteracts the negative effect of isolation on immigration on large islands. Continental islands were less affected by isolation than oceanic islands. Our results suggest that a variety of immigration mechanisms influence plant species richness on islands and we show that this can be detected at macro‐scales. Although the distance to the nearest mainland is an adequate and easy‐to‐calculate measure of isolation, accounting for stepping stones, large islands as source landmasses, climatic similarity and the area of surrounding landmasses increases the explanatory power of isolation for species richness.     

Chromosomal sequences and interisland colonizations in hawaiian Drosophila

Of 103 picture-winged Drosophila species endemic to the high Hawaiian islands, all but three are endemic to single islands or island complexes. They are presumed to have evolved in situ on each island. The banding pattern sequences of the five major polytene chromosomes of these species have been mapped to a single set of Standard sequences. Sequential variation among these chromosomes is due to 213 paracentric inversions. An atlas of their break points is provided. Geographical, morphological and behavioral data may be used to supplement the cytological information in tracing ancestry. Starting at the newer end of the archipelago, the 26 species of the Island of Hawaii (less than 700,000 years old) are inferred to have been derived from 19 founders, 15 from the Maui complex, three from Oahu and one from Kauai. The existence of 40 Maui complex species is explicable as resulting from 12 founders, ten from Oahu and two from Kauai. The 29 Oahu species can be explained by 12 founder events, five from Kauai and seven from Maui complex (summary in Figure 5). Although the ancestry of two Kauai species can be traced to newer islands, the ten remaining ones on this island (age about 5.6 million years) are apparently ancient elements in the fauna, relating ultimately to Palearctic continental sources.     

Biodiversity on oceanic islands:a palaeoecological assessment

Islands are bounded ecosystems and serve as excellent laboratories for assessing changes in Biodiversity. Some oceanic islands, such as Madagascar, Bermuda and notably the islands in the Pacific (e.g. Hawaii), are home to unique forms of endemic plants and animals that have evolved in isolation over millions of years. The palaeoecological record indicates that such islands are characterized by waves of extinctions concomitant with colonization by humans. By way of contrast, the biota of the islands of the north Atlantic (Greenland, Iceland and Faroe) do not follow the expected pattern and the few extinctions recorded are very localized. This is not a result of the scale of human impact, which is as great as on other islands, but relates to the virtual lack of endemics. The dearth of endemic forms and the disharmonic nature of these island communities indicates a youthful biota and the operation of severe filters and sweepstakes during colonisation over the last 10,000 years. This paper draws upon an extensive invertebrate fossil record to contrast and examine these spatial and temporal patterns in island Biodiversity.     

The impact of Quaternary Ice Ages on mammalian evolution

The Quaternary was a time of extensive evolution among mammals. Most living species arose at this time, and many of them show adaptations to peculiarly Quaternary environments. The latter include continental northern steppe and tundra, and the formation of lakes and offshore islands. Although some species evolved fixed adaptations to specialist habitats, others developed flexible adaptations enabling them to inhabit broad niches and to survive major environmental changes. Adaptation to short-term (migratory and seasonal) habitat change probably played a part in pre-adapting mammal species to the longer-term cyclical changes of the Quaternary. Fossil evidence indicates that environmental changes of the order of thousands of years have been sufficient to produce subspeciation, but speciation has typically required one hundred thousand to a few hundred thousand years, although there are both shorter and longer exceptions. The persistence of taxa in environments imposing strong selective regimes may have been important in forcing major adaptive change. Individual Milankovitch cycles are not necessarily implicated in this process, but nor did they generally inhibit evolutionary change among mammals: many evolutionary divergences built over multiple climatic cycles. Deduction of speciation timing requires input from fossils and modern phenotypic and breeding data, to complement and constrain mitochondrial DNA coalescence dates which appear commonly to overestimate taxic divergence dates and durations of speciation. Migrational and evolutionary responses to climate change are not mutually exclusive but, on the contrary, may be synergistic. Finally, preliminary analysis suggests that faunal turnover, including an important element of speciation, was elevated in the Quaternary compared with the Neogene, at least in some biomes. Macroevolutionary species selection or sorting has apparently resulted in a modern mammalian fauna enriched with fast-reproducing and/or adaptively generalist species.     

The evolution of male and female mating preferences in Drosophila speciation*

The relative importance of male and female mating preferences in causing sexual isolation between species remains a major unresolved question in speciation. Despite previous work showing that male courtship bias and/or female copulation bias for conspecifics occur in many taxa, the present study is one of the first large‐scale works to study their relative divergence. To achieve this, we used data from the literature and present experiments across 66 Drosophila species pairs. Our results revealed that male and female mate preferences are both ubiquitous in Drosophila but evolved largely independently, suggesting different underlying evolutionary and genetic mechanisms. Moreover, their relative divergence strongly depends on the geographical relationship of species. Between allopatric species, male courtship and female copulation preferences diverged at very similar rates, evolving approximately linearly with time of divergence. In sharp contrast, between sympatric species pairs, female preferences diverged much more rapidly than male preferences and were the only drivers of enhanced sexual isolation in sympatry and Reproductive Character Displacement (RCD). Not only does this result suggest that females are primarily responsible for such processes as reinforcement, but it also implies that evolved female preferences may reduce selection for further divergence of male courtship preferences in sympatry.     

Patterns of diversification on old volcanic islands as revealed by the woodlouse-hunter spider genus Dysdera (Araneae, Dysderidae) in the eastern Canary Islands

Long-term erosion and subsidence cause dramatic alterations in the physical and ecological features of oceanic islands. Although oceanic islands have been extensively used as models for the study of speciation, little attention has been given to investigating evolutionary patterns in old volcanic islands that have suffered severe climatic degradation. The spider genus Dysdera has diversified across the Canary Islands and has evolved endemisms in the low-elevation, xeric eastern islands, which sharply contrast with the younger, higher, and more humid western islands. A combined phylogenetic analysis of seven mitochondrial and nuclear genes reveals that the eastern Canaries were colonized twice, although only one lineage underwent in situ diversification. Origins of the speciose lineage remain obscure, but probably preceded diversification of present-day Iberian and North African species. A second colonization of the eastern Canaries from North Africa has occurred in more recent times. Molecular analyses reveal several instances of geographically coherent cryptic lineages further supported by morphometric evidence. Analyses of diversification rates suggest deceleration of diversification over the course of time, and this is compatible with increasing extinction rates due to drastic yet continuous ecological changes. Extinction may also explain incongruent patterns of morphological differentiation and species coexistence. Despite a general trend towards community impoverishment, there is also evidence for recent speciation events linked to ecological shifts, which may illustrate the origins of nonspeciose relic lineages on islands.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 589–615.     

Molecular phylogeny of the endemic Philippine rodent Apomys (Muridae) and the dynamics of diversification in an oceanic archipelago

We analysed the phylogenetic relationships of ten of the 13 known species of the genus Apomys using DNA sequences from cytochrome b . Apomys, endemic to oceanic portions of the Philippine archipelago, diversified during the Pliocene as these oceanic islands arose de novo . Several of the speciation events probably took place on Luzon or Mindanao, the two largest, oldest, and most topographically complex islands. Only one speciation event is associated with vicariance due to Pleistocene sea-level fluctuation, and a Pleistocene diversification model in which isolation is driven by sea-level changes is inconsistent with the data. Tectonic vicariance is nearly absent from the Philippines, in which tectonic coalescence plays a significant role. Most speciation events (about two-thirds) are associated with dispersal to newly developed oceanic islands. The data imply that the species have persisted for long periods, measured in millions of years after their origins; further implications therefore are that faunal turnover is very slow, and persistence over geological time spans is more prominent than repeated colonization and extinction. Neither the equilibrium nor the vicariance model of biogeography adequately encompasses these results; a model incorporating colonization, extinction, and speciation is necessary and must incorporate long-term persistence to accommodate our observations.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society, 2003, 80 , 699–715.