Biogeographic area relationships in southern New Zealand: a cladistic analysis of Lepidoptera distributions

ABSTRACT. Recently, attention has been directed toward the application of cladistic techniques to reconstruct the history of areas from species distribution data. In this study, hypotheses of area relationships for southern New Zealand are generated from lepidopteran distribution data analysed at two taxonomic levels. Data are shown to possess cladistic structure and area relationships presented here are consistent with the geological history of the southern region of New Zealand. Our results suggest a recolonization of inland lowland regions from the south following a period of extinction during the early Pliocene. Analysis of selected data including only flightless or locally endemic species resulted in little resolution of area relationships but topologies were significantly congruent with a total species dataset. Hypotheses generated from this study are open to testing with congruence analysis using independent species phylogenies.     

Macrolepidoptera diversity in the Indo-Australian tropics: geographic, biotopic and taxonomic variations

Data are presented on the richness of Macrolepidoptera faunas in the Indo-Australian tropics, and on the proportional representation of the various families. Both overall diversity and diversity of families decline with latitude and also with isolation from major land areas. Exceptions are noted.
Measures of alpha-diversity from quantitative light-trap samples indicate that diversity within the tropics is often greatest at altitudes around 1000 m, declining above that level. Diversity is much lower in Pacific archipelagos. Loss of diversity through disturbance and conversion to agriculture is evident and marked. Problems in the measurement of diversity with light-traps are discussed, exemplified by results obtained using different trap types.
Changes in family proportions with habitat type are examined. Family diversity generally decreased with altitude and with disturbance and conversion to agriculture, though there are exceptions to this decline.     

On the diversity of the Cladocera in the tropics

The mythical concept of an impoverished tropical cladoceran fauna is refuted. On a planetary scale, around half of the cladoceran species presently known occur exclusively in the tropics-subtropics, often with considerable restriction to particular geographical subzones. On a regional (political) scale, the situation is often unclear because of the continued fragmentary nature of studies, and because political units are not a good basis for biogeographical comparisons. At the finest level of resolution (lake-perlake comparisons), there appears to be an upper limit of c. 50 cladoceran species per individual lake. No significant difference between lakes in the temperate zone and in the tropics could be established here. Daphnia is largely absent from the tropics, but is replaced by more Sidids, Moinids, and Bosminids, such that the average cladoceran community in the limnetic zone of a tropical lake is not characterized by less species but rather by lower population densities. This, in turn, is considered a consequence of higher prevalent predation levels in the tropics.     

Multiple intercontinental dispersals shaped the distribution area of Hordeum (Poaceae)

The grass genus Hordeum (Poaceae, Triticeae), comprising 31 species distributed in temperate and dry regions of the world, was analysed to determine the relative contributions of vicariance and long-distance dispersal to the extant distribution pattern of the genus. Sequences from three nuclear regions (DMC1, EF-G and ITS) were combined and analysed phylogenetically for all diploid (20 species) and two tetraploid Hordeum species and the outgroup Psathyrostachys. Ages of clades within Hordeum were estimated using a penalized likelihood analysis of sequence divergence. The sequence data resulted in an almost fully resolved phylogenetic tree that allowed the reconstruction of intrageneric migration routes. Hordeum evolved c. 12 million years ago in South-west Asia and spread into Europe and Central Asia. The colonization of the New World and South Africa involved at least six intercontinental exchanges during the last 4 million years (twice Eurasia-North America, North America-South America, twice South America-North America and Europe-South Africa). Repeated long-distance dispersal between the northern and southern hemisphere were important colonization mechanisms in Hordeum.     

Vicariance, dispersal and scale in the aquatic subterranean fauna of karst regions

1. The causes of distribution patterns of stygobionts (obligate subterranean-dwelling aquatic species) were examined with special emphasis on vicariance and dispersal.
2. Dispersal was investigated on the premise that if migration is important, then migration at small scales should predict patterns at larger scales. Data on the copepod fauna of epikarst in Slovenia were especially useful for the study of migration, because data on habitat occupancy could be collected at scales of individual drips located metres apart to the scale of individual caves to entire karst regions. Occupancy of drips in one cave was a remarkably good predictor of occupancy of caves in a region, although not of the overall range of a given species. These results were also supported by occupancy patterns of the general stygobiotic fauna of West Virginia caves, compared at different scales.
3. Vicariance was investigated by noting that proximity to marine embayments increases the likelihood of vicariant speciation. In the U.S.A., only the fauna of the Edwards Aquifer of Texas has a significant component of marine-derived species. Differences in shape of the relationship between species number and number of caves in a county indicated that the marine-derived component represented an addition to rather than a replacement of the other stygobiotic species.
4. Thus, we found evidence for the importance of both vicariance and dispersal. The techniques employed could be used to study these patterns more generally, as more data become available.     

Divergence time of the two regional medaka populations in Japan as a new time scale for comparative genomics of vertebrates

The southern and northern Japanese populations of the medaka fish provide useful tools to gain insights into the comparative genomics and speciation of vertebrates, because they can breed to produce healthy and fertile offspring despite their highly divergent genetic backgrounds compared with those of human–chimpanzee. Comparative genomics analysis has suggested that such large genetic differences between the two populations are caused by higher molecular evolutionary rates among the medakas than those of the hominids. The argument, however, was based on the assumption that the two Japanese populations diverged approximately at the same time (4.0–4.7 Myr ago) as the human–chimpanzee lineage (5.0–6.0 Myr ago). This can be misleading, because the divergence time of the two populations was calculated based on estimated, extremely higher molecular evolutionary rates of other fishes with an implicit assumption of a global molecular clock. Here we show that our estimate, based on a Bayesian relaxed molecular-clock analysis of whole mitogenome sequences from 72 ray-finned fishes (including 14 medakas), is about four times older than that of the previous study (18 Myr). This remarkably older estimate can be reconciled with the vicariant events of the Japanese archipelago, and the resulting rates of molecular evolution are almost identical between the medaka and hominid lineages. Our results further highlight the fact that reproductive isolation may not evolve despite a long period of geographical isolation.     

The dynamics of biogeographic ranges in the deep sea

Anthropogenic disturbances such as fishing, mining, oil drilling, bioprospecting, warming, and acidification in the deep sea are increasing, yet generalities about deep-sea biogeography remain elusive. Owing to the lack of perceived environmental variability and geographical barriers, ranges of deep-sea species were traditionally assumed to be exceedingly large. In contrast, seamount and chemosynthetic habitats with reported high endemicity challenge the broad applicability of a single biogeographic paradigm for the deep sea. New research benefiting from higher resolution sampling, molecular methods and public databases can now more rigorously examine dispersal distances and species ranges on the vast ocean floor. Here, we explore the major outstanding questions in deep-sea biogeography. Based on current evidence, many taxa appear broadly distributed across the deep sea, a pattern replicated in both the abyssal plains and specialized environments such as hydrothermal vents. Cold waters may slow larval metabolism and development augmenting the great intrinsic ability for dispersal among many deep-sea species. Currents, environmental shifts, and topography can prove to be dispersal barriers but are often semipermeable. Evidence of historical events such as points of faunal origin and climatic fluctuations are also evident in contemporary biogeographic ranges. Continued synthetic analysis, database construction, theoretical advancement and field sampling will be required to further refine hypotheses regarding deep-sea biogeography.     

Phylogenetic tests of distribution patterns in South Asia: towards an integrative approach

The last four decades have seen an increasing integration of phylogenetics and biogeography. However, a dearth of phylogenetic studies has precluded such biogeographic analyses in South Asia until recently. Noting the increase in phylogenetic research and interest in phylogenetic biogeography in the region, we outline an integrative framework for studying taxon distribution patterns. While doing so, we pay particular attention to challenges posed by the complex geological and ecological history of the region, and the differences in distribution across taxonomic groups. We outline and compare three widely used phylogenetic biogeographic approaches: topology-based methods (TBMs), pattern-based methods (PBMs) and event-based methods (EBMs). TBMs lack a quantitative framework and utilize only part of the available phylogenetic information. Hence, they are mainly suited for preliminary enquiries. Both PBMs and EBMs have a quantitative framework, but we consider the latter to be particularly suited to the South Asian context since they consider multiple biogeographic processes explicitly, and can accommodate a reticulated history of areas. As an illustration, we present a biogeographic analysis of endemic Sri Lankan agamid lizards. The results provide insights into the relative importance of multiple processes and specific zones in the radiation of two speciose lizard clades.     

The effects of island area, isolation and source population size on the presence of the grayling butterfly Hipparchia semele (L.) (Lepidoptera: Satyrinae) on British and Irish offshore islands

Records of Hipparchia semele on British and Irish islands have been modelled against island area, isolation (sea and land distance) and the size of the nearest potential source populations. All three variables have been found to contribute significantly to the presence or absence of H. semele on the islands. Isolation is a more significant predictor than island area. This result differs from the multiple species case where area was found to be a more important influence than isolation. Records on islands are also shown to depend on the size of populations at the nearest sources; this underpins the relationships identified for the multiple species case, first, between the number of species on islands and at nearest sources and, second, between the incidence of species on islands and at nearest sources. There are clear indications that smaller islands may become increasingly marginalized for H.semele; with ongoing habitat loss, because isolation increases and source populations become sparser, the probability of H. semele recolonizing islands also decreases.     

Colonization of and radiation in South America by butterflies in the subtribe Phyciodina (Lepidoptera: Nymphalidae)

The historical biogeography of insects in South America is largely unknown, as dated phylogenies have not been available for most groups. We have studied the phylogenetic relationships and historical biogeography of a subtribe of butterflies, Phyciodina in the family Nymphalidae, based on one mitochondrial gene (COI) and two nuclear gene regions (EF-1alpha and wingless). The subtribe comprises 89 species mainly found in tropical South America, with a few species in North America and the Greater Antilles. We find that the enigmatic genus Antillea is sister to the rest of Phyciodina, and suggest that it should be included in the subtribe. Several genera are found to be polyphyletic or nested within another genus, and are proposed to be synonymised. These are Dagon, Castilia, Telenassa and Janatella, which we propose should be synonymised with Eresia. Brazilian "Ortilia" form an independent lineage and require a new genus name. The diversification of Phyciodina has probably taken place over the past about 34 MYA. The ancestral phyciodine colonised South America from North America through a possible landspan that connected the Greater Antilles to South America about 34MYA. A vicariance event left the ancestral Antillea on the Greater Antilles, while the ancestral 0e on South America colonised the Guyanan Shield and soon after the Brazilian Shield. We hypothesise that the Brazilian Shield was an important area for the diversification of Phyciodina. From there, the ancestor of Anthanassa, Eresia and Tegosa colonised NW South America, where especially Eresia diversified in concert with the rising of the Andes beginning about 20 MYA. Central America was colonised from NW South America about 15 MYA by the ancestors of Anthanassa and Phyciodes. Our study is the first to use a dated phylogeny to study the historical biogeography of a group of South American species of butterflies.     

New Zealand phylogeography: evolution on a small continent

New Zealand has long been a conundrum to biogeographers, possessing as it does geophysical and biotic features characteristic of both an island and a continent. This schism is reflected in provocative debate among dispersalist, vicariance biogeographic and panbiogeographic schools. A strong history in biogeography has spawned many hypotheses, which have begun to be addressed by a flood of molecular analyses. The time is now ripe to synthesize these findings on a background of geological and ecological knowledge. It has become increasingly apparent that most of the biota of New Zealand has links with other southern lands (particularly Australia) that are much more recent than the breakup of Gondwana. A compilation of molecular phylogenetic analyses of ca 100 plant and animal groups reveals that only 10% of these are even plausibly of archaic origin dating to the vicariant splitting of Zealandia from Gondwana. Effects of lineage extinction and lack of good calibrations in many cases strongly suggest that the actual proportion is even lower, in keeping with extensive Oligocene inundation of Zealandia. A wide compilation of papers covering phylogeographic structuring of terrestrial, freshwater and marine species shows some patterns emerging. These include: east–west splits across the Southern Alps, east–west splits across North Island, north–south splits across South Island, star phylogenies of southern mountain isolates, spread from northern, central and southern areas of high endemism, and recent recolonization (postvolcanic and anthropogenic). Excepting the last of these, most of these patterns seem to date to late Pliocene, coinciding with the rapid uplift of the Southern Alps. The diversity of New Zealand geological processes (sinking, uplift, tilting, sea level change, erosion, volcanism, glaciation) has produced numerous patterns, making generalizations difficult. Many species maintain pre‐Pleistocene lineages, with phylogeographic structuring more similar to the Mediterranean region than northern Europe. This structure reflects the fact that glaciation was far from ubiquitous, despite the topography. Intriguingly, then, origins of the flora and fauna are island‐like, whereas phylogeographic structure often reflects continental geological processes.     

Relationships among fire frequency, rainfall and vegetation patterns in the wet–dry tropics of northern Australia: an analysis based on NOAA-AVHRR data

Aim To quantify the regional‐scale spatio‐temporal relationships among rainfall, vegetation and fire frequency in the Australian wet–dry tropics (AWDT). Location Northern Australia: Cape York Peninsula, central Arnhem, central Kimberly, Einasleigh Uplands, Gulf Fall Uplands and northern Kimberley. Methods Monthly ‘fraction of photosynthetic active radiation absorbed by green vegetation’ (fAPAR) was decomposed into monthly evergreen (EG) and monthly raingreen (RG) components using time‐series techniques applied to monthly normalized difference vegetation index (NDVI) data from Advanced Very High Resolution Radiometer (AVHRR) imagery. Fire affected areas were independently mapped at the same spatio‐temporal resolution from AVHRR imagery. Weather station records were spatially interpolated to create monthly rainfall surfaces. Vegetation structural classes were derived from a digitized map of northern Australian vegetation communities (1 : 1,000,000). Generalized linear models were used to quantify relationships among the fAPAR, EG and RG signals, vegetation structure, rainfall and fire frequency, for the period November 1996–December 2001. Results The fAPAR and EG signals are positively correlated with annual rainfall and canopy cover, notably: EG_{closed forest} > EG_{open heathland} > EG_{open forest} > EG_woodland > EG_{open woodland} > EG_{low woodland} > EG_{low open woodland} > EG_{open grassland}. Vegetation height and fAPAR are positively correlated, excluding the special case of open heathland. The RG signal is highest where intermediate annual rainfall and strong seasonality in rainfall coincide, and is associated with vegetation structure as follows: RG_{open grassland} > RG_woodland > RG_{open forest} > RG_{open heathland} > RG_{low woodland} > RG_{open woodland} > RG_{low open woodland} > RG_{closed forest}. Monthly RG tracks monthly rainfall. Annual proportion of area burnt (PB) is maximal where high RG coincides with low EG (open grassland, several woodland communities). PB is minimal in vegetation where both RG and EG are low (low open woodland); and in vegetation where EG is high (closed forest, open heathland). Conclusions The RG–EG scheme successfully reflects digitally mapped tree and grass covers in relation to rainfall. RG–EG patterns are strongly associated with fire frequency patterns. PB is maximal in areas of high RG, where high biomass production during the wet season supports abundant fine fuel during the dry season. PB is minimal in areas with high EG, where relatively moist fuel limits fire ignition; and in areas with low EG and RG, where a relative short supply of fuel limits fire spread.     

Gene lineages and eastern North American palaeodrainage basins: phylogeography and speciation in salamanders of the Eurycea bislineata species complex

Contemporary North American drainage basins are composites of formerly isolated drainages, suggesting that fragmentation and fusion of palaeodrainage systems may have been an important factor generating current patterns of genetic and species diversity in stream-associated organisms. Here, we combine traditional molecular-phylogenetic, multiple-regression, nested clade, and molecular-demographic analyses to investigate the relationship between phylogeographic variation and the hydrogeological history of eastern North American drainage basins in semiaquatic plethodontid salamanders of the Eurycea bislineata species complex. Four hundred forty-two sequences representing 1108 aligned bases from the mitochondrial genome are reported for the five formally recognized species of the E. bislineata complex and three outgroup taxa. Within the in-group, 270 haplotypes are recovered from 144 sampling locations. Geographic patterns of mtDNA-haplotype coalescence identify 13 putatively independent population-level lineages, suggesting that the current taxonomy of the group underestimates species-level diversity. Spatial and temporal patterns of phylogeographic divergence are strongly associated with historical rather than modern drainage connections, indicating that shifts in major drainage patterns played a pivotal role in the allopatric fragmentation of populations and build-up of lineage diversity in these stream-associated salamanders. More generally, our molecular genetic results corroborate geological and faunistic evidence suggesting that palaeodrainage connections altered by glacial advances and headwater erosion occurring between the mid-Miocene and Pleistocene epochs explain regional patterns of biodiversity in eastern North American streams.     

Phylogenetic biogeography of the leafy liverwort Herbertus (Jungermanniales, Herbertaceae) based on nuclear and chloroplast DNA sequence data: correlation between genetic variation and geographical distribution

Aim The cosmopolitan genus Herbertus is notorious for having a difficult taxonomy and for the fact that there is limited knowledge of species ranges and relationships. Topologies generated from variable molecular markers are used to discuss biogeographical patterns in Herbertus and to compare them with the geological history of continents and outcomes reported for other land plants. Location Africa, Asia, Azores, Europe, southern South America, northern South America, North America, New Zealand. Methods Phylogenetic analyses of nuclear ribosomal internal transcribed spacer and chloroplast (cp) trnL–trnF sequences of 66 accessions of Herbertus and the outgroup species Triandrophyllum subtrifidum and Mastigophora diclados were used to investigate biogeographical patterns in Herbertus. Areas of putative endemism were defined based on the distribution of species included in the analyses. Maximum parsimony analyses were undertaken to reconstruct ancestral areas and intraspecies migration routes. Results The analyses reveal species‐level cladograms with a correlation between genetic variation and the geographical distribution of the related accessions. The southern South American Herbertus runcinatus is sister to the remainder of the genus, which is split into two main clades. One contains the Neotropical–African Herbertus juniperoideus and the New Zealand/Tasmanian Herbertus oldfieldianus. An African accession of H. juniperoideus is nested within Neotropical accessions. The second main clade includes species that inhabit Asia, the Holarctic, Africa, and northern South America. Maximum parsimony analyses indicate that this clade arose in Asia. Herbertus sendtneri originated in Asia and subsequently colonized the Holarctic and northern South America. An Asian origin and colonization into Africa is indicated for H. dicranus. Main conclusions The current distribution of Herbertus cannot be explained by Gondwanan vicariance. A more feasible explanation of the range is a combination of short‐distance dispersal, rare long‐distance dispersal events (especially into regions that faced floral displacements as a result of climatic changes) extinction, recolonization, and diversification. The African Herbertus flora is a mixture of Asian and Neotropical elements. Southern South America harbours an isolated species. The molecular data indicate partial decoupling of molecular and morphological variation in Herbertus. Biogeographical patterns in Herbertus are not dissimilar to those of other groups of bryophytes, but elucidation of the geographical ranges requires a molecular approach. Some patterns could be the result of maintenance of Herbertus in the inner Tropics during glacial maxima, and dispersal into temperate regions in warm phases.     

Mechanisms of communication disruption by pheromone in the control of Lepidoptera: a review

ABSTRACT. Five possible mechanisms involved in the disruption of phero-mone-mediated behaviour in the control of lepidopterous pests are discussed. The various techniques used in the field, laboratory investigations of such mechanisms, and possible limitations in the application of such studies, are reviewed.     

Dispersal and diversity in the earliest North American sauropodomorph dinosaurs, with a description of a new taxon

Sauropodomorph dinosaurs originated in the Southern Hemisphere in the Middle or Late Triassic and are commonly portrayed as spreading rapidly to all corners of Pangaea as part of a uniform Late Triassic to Early Jurassic cosmopolitan dinosaur fauna. Under this model, dispersal allegedly inhibited dinosaurian diversification, while vicariance and local extinction enhanced it. However, apomorphy-based analyses of the known fossil record indicate that sauropodomorphs were absent in North America until the Early Jurassic, reframing the temporal context of their arrival. We describe a new taxon from the Kayenta Formation of Arizona that comprises the third diagnosable sauropodomorph from the Early Jurassic of North America. We analysed its relationships to test whether sauropodomorphs reached North America in a single sweepstakes event or in separate dispersals. Our finding of separate arrivals by all three taxa suggests dispersal as a chief factor in dinosaurian diversification during at least the early Mesozoic. It questions whether a 'cosmopolitan' dinosaur fauna ever existed, and corroborates that vicariance, extinction and dispersal did not operate uniformly in time or under uniform conditions during the Mesozoic. Their relative importance is best measured in narrow time slices and circumscribed geographical regions.     

The age and origin of the Pacific islands: a geological overview

The Pacific Ocean evolved from the Panthalassic Ocean that was first formed ca 750 Ma with the rifting apart of Rodinia. By 160 Ma, the first ocean floor ascribed to the current Pacific plate was produced to the west of a spreading centre in the central Pacific, ultimately growing to become the largest oceanic plate on the Earth. The current Nazca, Cocos and Juan de Fuca (Gorda) plates were initially one plate, produced to the east of the original spreading centre before becoming split into three. The islands of the Pacific have originated as: linear chains of volcanic islands on the above plates either by mantle plume or propagating fracture origin, atolls, uplifted coralline reefs, fragments of continental crust, obducted portions of adjoining lithospheric plates and islands resulting from subduction along convergent plate margins. Out of the 11 linear volcanic chains identified, each is briefly described and its history summarized. The geology of 10 exemplar archipelagos (Japan, Izu-Bonin, Palau, Solomons, Fiji, New Caledonia, New Zealand, Society, Galápagos and Hawaii) is then discussed in detail.     

Phylogeography of the livebearer Xenophallus umbratilis (Teleostei: Poeciliidae): glacial cycles and sea level change predict diversification of a freshwater tropical fish

The biogeography of Central America is viewed as a classic case study in understanding the impact of vicariant events on patterns of biotic dispersal. While many biogeographers have focused on community composition and geographical limits of species at broad scales across Central America, much less work has focused on post-colonization diversification patterns at finer scales. The livebearing freshwater fish Xenophallus umbratilis presents an ideal system for determining the impact of recent Earth history events on biodiversity in northern Costa Rica. Here, we test the hypotheses that marine inundation of the San Carlos and northern Limón basins during the Pliocene and Pleistocene has caused genetic fragmentation among X. umbratilis populations, despite contemporary freshwater connections. To test this idea, we collected mitochondrial (cytochrome b ) sequence data in 162 individuals taken from 27 localities across northern Costa Rica. We employed a variety of analytical approaches, including: maximum parsimony and maximum likelihood, analysis of molecular variance, and demographic analysis of population size through time. We found four major clades within X. umbratilis , each geographically isolated with no shared haplotypes across drainages. Oddly, clades that occupy adjacent drainages are not always sister taxa in the phylogeny, suggesting that colonization in this species is more complex than a simple model of isolation by distance. All our results are consistent with the hypothesis that changes in sea level associated with glacial eustatic cycles have had an important effect in shaping diversification patterns in this species.