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A new fossil site in a previously unexplored part of western Madagascar (the Beanka Protected Area) has yielded remains of many recently extinct vertebrates, including giant lemurs (Babakotia radofilai, Palaeopropithecus kelyus, Pachylemur sp., and Archaeolemur edwardsi), carnivores (Cryptoprocta spelea), the aardvark-like Plesiorycteropus sp., and giant ground cuckoos (Coua). Many of these represent considerable range extensions. Extant species that were extirpated from the region (e.g., Prolemur simus) are also present. Calibrated radiocarbon ages for 10 bones from extinct primates span the last three millennia. The largely undisturbed taphonomy of bone deposits supports the interpretation that many specimens fell in from a rock ledge above the entrance. Some primates and other mammals may have been prey items of avian predators, but human predation is also evident. Strontium isotope ratios (87Sr/86Sr) suggest that fossils were local to the area. Pottery sherds and bones of extinct and extant vertebrates with cut and chop marks indicate human activity in previous centuries. Scarcity of charcoal and human artifacts suggests only occasional visitation to the site by humans. The fossil assemblage from this site is unusual in that, while it contains many sloth lemurs, it lacks ratites, hippopotami, and crocodiles typical of nearly all other Holocene subfossil sites on Madagascar.
Silphium spp. have garnered interest in Europe as a bioenergy crop and in North America as a perennial oilseed crop. However, very little has been done at this early stage of domestication to characterize wild collections for many key characteristics, including important oilseed traits. The objective of this work was to develop a basic understanding of how biogeography and associated population genetic forces have shaped seed phenotypes in plant collections across the native range of Silphium integrifolium Michx. (Asteraceae: Heliantheae), the primary domestication candidate for oilseed use. A collection of 53 accessions was grown in a common environment in Salina, KS, which is a location well within the native range of the species in central North America. Plants from each collection site were randomly mated by hand to produce seed representative of each accession, and the seeds subjected to seed dimensional trait, oil content and oil composition analyses. Kernel width varied along a latitudinal cline of collection site, while kernel length varied across a longitudinal cline. Palmitic and linoleic acids were inversely correlated with each other and varied along a longitudinal cline of the collection site. The results indicate that accessions collected from more southwesterly sites tended to have larger seed and those from more westerly sites had higher linoleic acid content and lower palmitic and myristic acids, which are all desirable phenotypes for an oilseed Silphium.
Three broad contributions have recently emerged from South African marine biology. First, even strong environmental and biological effects like upwelling are context dependent, nested in biogeography and differ from fine to coarse taxonomic scales. This can lead to small-scale spatial predictability in grazing effects. While top-down control, including fishing, is critical in shallow subtidal systems, the intertidal exhibits stronger bottom-up regulation. Second, phylogeographic patterns can be strong, without coinciding with biogeographic boundaries. This is important because intra-specific genetic lineages can show critical differences in behaviour and physiology, making species responses to environmental change and biological interactions variable at the population level. Third, many non-indigenous species have come to light. Few have become invasive, but they can have dramatic effects, positive and negative. Their simple distributional patterns emerge from complex interactions of many variables, making predicting species distributions under climate change difficult.
The rocky intertidal of the Argentinean coast extends 7,000 km from Río de la Plata (36°S) to Tierra del Fuego (54°S). Intertidal rocky platforms increase in frequency and extent from north to south. In the north, part of this extension has a microtidal nature changing to meso- and macro-tidal in southern Patagonia. The rocky shores of Argentina are characterised by low biodiversity and low biomass compared with other parts of the world. There is an increase in biodiversity at high latitudes, an opposite trend to the current paradigm. Facilitation, competition and grazers shape these patterns at local scales, while there are few predators and their size is frequently small, having lower effects than predators in other coasts. The role of invasive species and anthropogenic impacts on the rocky shores are reviewed as well as the global change effect along the coast. We conclude by considering the knowledge gaps and the special features of Argentine rocky shores which are shaped by their environmental setting and phylogeographic history leading to low diversity, missing functional groups for some taxa and a gradient of increasing diversity towards the poles.
Biogeography, phylogeography and ecology of the diverse assemblage that inhabits the south-east Pacific along the Humboldt Current system (HCS) has received increasing attention. Regions separated by biogeographic break evidence changes in the functional structure of consumer assemblages, likely related to a replacement from tropical to temperate species. The deep temporal signature of coastal oceanography on coastal biogeography and phylogeography is underpinned by the spatial structure of bottom-up effects of ecological processes, which also influence the strong top-down regulation of consumers on the structure of rocky shore communities. Uncertainties still remain about how coastal oceanographic processes regulate species range expansion/contraction and how biotic interactions and environmental filtering define dynamic biogeographic patterns along marine environments. Explicit predictions should be made regarding the persistence and dynamics of species ranges, and changing ecological interactions among species in the face of intensified human harvesting (e.g., kelps) and global change. Clear cooling trends are observed across the HCS, human harvesting is intensifying and presence of coastal artificial infrastructure could trigger species range shift. Aquaculture expansion and the introduction of exotic non-native species have the potential to alter community structure and functioning. Hence, ecosystem services should be managed, and necessary interventions carefully planned to ensure sustainability of use of natural marine resources and coastal ecosystem integrity.
The ‘deep sea’ encompasses a broad range of habitats that differ greatly in their assemblages and ecosystem functioning. Habitats may be described by a combination of environmental factors (e.g., depth, slope) and biotic factors (e.g., source of primary productivity). We review recent attempts to define deep-sea biogeographic provinces based on spatial and temporal variations in oceanographic conditions, and consider potential boundaries to distributional ranges, in particular habitats based on recent phylogeographic studies. We briefly discuss abiotic interactions in various habitats, noting the particular influence of local hydrodynamics. We consider competition and predation at whale falls and hydrothermal vents, discuss symbiotic interactions particularly with respect to deep-sea corals, which are particularly prevalent in submarine canyons and seamounts, and consider the difficulties of inferring processes from patterns.
The rocky shores of New Zealand (NZ) and Australia provide many interesting comparisons in their intertidal species and structuring processes. Both countries are in the biogeographic realm of temperate Australasia and share many common species and closely related taxa. Here we review similarities and contrasts in communities and structuring processes, especially involving grazing invertebrates and macroalgae. We consider the similarity of the structure of intertidal shores of NZ and south-eastern Australia, a suite of important trophic interactions within and between regions, the utility of local-scale experiments in understanding large-scale processes and how we might better plan for and manage our coasts. The major comparisons are between warm-temperate areas of northern NZ and New South Wales, and the cooler areas of southern NZ and south-eastern Australia. In the quest for ‘ecosystem’-level understanding, which perforce involves large-scale events, there is an increasing tendency to minimise or ignore the hard-won insights gained from well-structured experiments across multiple sites. Because all large-scale effects must be manifested at local sites, it is incumbent on us to determine what scales up or down, and the caveats that make comparisons across biogeographic regions challenging. Here, we discuss these issues using austral shores as models.
The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
We summarise processes determining large-scale patterns of distribution and abundance of macroinfauna from Florida to Newfoundland, ~25°N to 52°N, focussing on intertidal and shallow subtidal (~ 5 m depth) muddy sands and sandy muds, habitats with abundant experimental data. Within the theme of geographic distribution of processes, mechanisms and patterns we suggest latitudinal patterns will likely change most as climate changes intensify. Published studies support the following major biogeographic patterns: (1) reduced importance of large disturbance predators north of Cape Cod, driven by latitudinal shifts in thermal regimes; (2) large digging predators from Delaware Bay (39.25°N) southwards dramatically reduce infaunal densities, restricting competitive interactions; (3) disturbance refugia, e.g., Zostera, drive southern spatial patterns; (4) rising seawater temperatures and reduced water clarity limit the extent and diversity of rooted plants in the south and mid-Atlantic; (5) latitudinal changes in tidal regimes result in greater aerial exposure in the north, magnifying latitudinal sea surface temperature changes; (6) ice cover intensifies to the north and (7) the Boston−Washington, DC megalopolis accentuates human signatures through eutrophication between 36.5°N and 42.6°N. Finally, we discuss potential shifts with climate change in these latitudinal patterns and processes.
Understanding factors that influence the spatial and temporal distributions of blood parasites is important to help predict how host species and their parasites may respond to global change. Factors that may influence parasite distributions are land cover and host dispersal patterns, which may result in exposure of a host to novel parasites, or escape from parasites of their origin. We screened golden-winged warblers from across the United States and Canada for blood parasites, and investigated whether land-use patterns or host dispersal affected the prevalence and composition of haemosporidian assemblages. Parasite prevalence varied strongly with study area, and areas with high agricultural cover had a significantly higher prevalence of Leucocytozoon and Parahaemoproteus parasites. Lineages of Parahaemoproteus and Leucocytozoon were genetically differentiated among study areas, and prevalence and composition of parasite assemblages indicated an increase in parasite prevalence and accumulation of unique parasite lineages from the southeast to the northwest. This matches the historical range expansion and natal dispersal patterns of golden-winged warblers, and suggests that golden-winged warblers may have been sensitive to novel parasites as they dispersed. The high prevalence and diversity of parasite lineages in the north-west extent of their breeding range (Manitoba) indicates that this population may face unique pressures.
During the expedition POS397 ‘GroMet’ in 2010 the sediments of the Great Meteor Seamount (GMS) plateau were sampled quantitatively for the first time, allowing statistical analysis of the community structure of Harpacticoida and Canuelloida. Analysis of similarity revealed no differences between three geographic regions at family/species level. Analysis of diversity indicated slightly greater diversity in the south, with more species belonging to more genera/families. Dispersal opportunities possibly occurring at the plateau (emergence, erosion, rafting) are discussed. Of 18 investigated families 106 species were identified, but only 5.66% were already scientifically known and widely distributed. Within the investigated families, 37.74% of the species belonged to shallow-water genera, leading to the conclusion that the plateau was once connected to shallow-water habitats, perhaps functioning as a stepping stone, but is now geographically isolated. This isolation is most likely due to seafloor spreading of the Atlantic Ocean and descending of the GMS. On the plateau, six species with wider distribution ranges were present, indicating that species may arrive accidentally, but their means of settlement remains unknown. Comparisons of the identified GMS plateau fauna with that of other seamounts and mid-oceanic islands revealed similar communities at family level, but at species level the GMS shares only one species with the Seine Seamount; all other elevations had more species in common. Hence, the GMS plateau is considered to be isolated regarding benthic Copepoda but may play an important role in meiofaunal species distribution, as it represents a shallow-water habitat within the deep sea.
Unlike most bird species, individual kingfisher species (Aves: Alcedinidae) are typically parasitized by only a single genus of louse (Alcedoffula, Alcedoecus, or Emersoniella). These louse genera are typically specific to a particular kingfisher subfamily. Specifically, Alcedoecus and Emersoniella parasitize Halcyoninae, whereas Alcedoffula parasitizes Alcedininae and Cerylinae. Although Emersoniella is geographically restricted to the Indo-Pacific region, Alcedoecus and Alcedoffula are geographically widespread. We used DNA sequences from two genes, the mitochondrial COI and nuclear EF-1α genes, to infer phylogenies for the two geographically widespread genera of kingfisher lice, Alcedoffula and Alcedoecus. These phylogenies included 47 kingfisher lice sampled from 11 of the 19 currently recognized genera of kingfishers. We compared louse phylogenies to host phylogenies to reconstruct their cophylogenetic history. Two distinct clades occur within Alcedoffula, one that infests Alcedininae and a second that infests Cerylinae. All species of Alcedoecus were found only on host species of the subfamily Halcyoninae. Cophylogenetic analysis indicated that Alcedoecus, as well as the clade of Alcedoffula occurring on Alcedininae, do not show evidence of cospeciation. In contrast, the clade of Alcedoffula occurring on Cerylinae showed strong evidence of cospeciation.
The Umbilicaria polyphylla aggregate (U. polyphylla (L.) Baumg., U. subpolyphylla Oxner and U. iberica Sancho & Krzewicka) is discussed based on morphological, chemical and molecular data. Umbilicaria iberica is proposed to be a later synonym of U. subpolyphylla. The constructed nrITS + mtLSU phylogeny, which includes specimens with wide geographical ranges, shows that both U. polyphylla and U. subpolyphylla are monophyletic and closely related. Both species have the same type of thalloconidia and identical secondary metabolites. Umbilicaria subpolyphylla has prominent phenotypic differences when compared to U. polyphylla including the monophyllous thallus with a dull upper surface and an elevated, slightly wrinkled centre, often covered with white pruina, and a medulla of the ‘U. havaasii’ type. Phylogenetic evidence for the bipolar distribution of both U. polyphylla and U. subpolyphylla is provided. Sympatric speciation in one region followed by long-distance dispersal seems to be the most plausible phylogeographical explanation for the observed patterns. Umbilicaria subpolyphylla is found in southern temperate-subtropical (Mediterranean) mountains, at least in Europe.
A new insular species of Paraethomys (Muridae, Rodentia) with medium-sized hypsodont teeth is described from the Zanclean of Mallorca (Balearic Islands, western Mediterranean). The m1 displays the most distinctive traits: hypsodonty, a high occurrence of an unusual anterior cingulum, a well-developed labial cingulum, high accessory labial cuspids resembling the Apodemus pattern and a funnel between c1 and the hypoconid. Paraethomys balearicus sp. nov. preserves traits close to those present in the earliest populations of Paraethomys meini from the upper Turolian, such as a developed posterior spur on t3 in the M1, a connection between t4 and t8 in the M1, a narrow connection between t6 and t9 in the M1 and the occasional presence of an individualized t9 and a t12 in some M2s. The relationship between the new taxon and its direct mainland ancestor gives additional support to a Messinian origin for the so-called Myotragus fauna, which became isolated after the refilling of the Mediterranean Sea 5.33 Ma ago. The absence of Paraethomys in other known younger Mallorcan sites suggests that its extinction most probably occurred at an indeterminate time during the Pliocene Epoch.
Icacinaceae Miers are a family of trees, shrubs, and lianas with a current pantropical distribution. The family is well known in the fossil record, especially from the Palaeogene of Europe and North America, with the modern genus Iodes being particularly well represented. Here, we describe five new species of Iodes based on fossil endocarps with horn-like protrusions from the late Palaeocene Rivecourt deposits (Oise, France). Moreover, we propose a new combination for Iodes israelii Soudry & Gregor, as Icacinicarytes israelii (Soudry & Gregor) Del Rio, Thomas & De Franceschi, because it lacks the diagnostic morphological and anatomical characters of the genus Iodes. The significance of papillae, which has been emphasised in the literature, is discussed in light of new data, and a more standardised system of terminology is proposed. Given that, among modern members of Iodes, horn-like protrusions are only known from Asian species; the fossils described here suggest an affinity between the late Palaeocene flora of Europe and the modern flora of Asia. Finally, this study represents the first detailed investigation of Icacinaceae from the Paris Basin, where palaeocarpology remains understudied.
The biogeographic histories of parasites and pathogens are infrequently compared with those of free-living species, including their hosts. Documenting the frequency with which parasites and pathogens disperse across geographic regions contributes to understanding not only their evolution, but also the likelihood that they may become emerging infectious diseases. Haemosporidian parasites of birds (parasite genera Plasmodium, Haemoproteus and Leucocytozoon) are globally distributed, dipteran-vectored parasites. To date, over 2000 avian haemosporidian lineages have been designated by molecular barcoding methods. To achieve their current distributions, some lineages must have dispersed long distances, often over water. Here we quantify such events using the global avian haemosporidian database MalAvi and additional records primarily from the Americas. We scored lineages as belonging to one or more global biogeographic regions based on infection records. Most lineages were restricted to a single region but some were globally distributed. We also used part of the cytochrome b gene to create genus-level parasite phylogenies and scored well-supported nodes as having descendant lineages in regional sympatry or allopatry. Descendant sister lineages of Plasmodium, Haemoproteus and Leucocytozoon were distributed in allopatry in 11, 16 and 15% of investigated nodes, respectively. Although a small but significant fraction of the molecular variance in cytochrome b of all three genera could be explained by biogeographic region, global parasite dispersal likely contributed to the majority of the unexplained variance. Our results suggest that avian haemosporidian parasites have faced few geographic barriers to dispersal over their evolutionary history.
Many of the most diverse clades of Late Palaeozoic echinoids (sea urchins) originated in the Devonian period. Our understanding of diversity dynamics of these Late Palaeozoic clades are thus informed by new systematic descriptions of some of their earliest members. The Proterocidaridae are a diverse and morphologically distinct clade of stem group echinoids with flattened tests and enlarged adoral pore pairs, which are first known from the Upper Devonian. We herein report on a new species of Hyattechinus, Hyattechinus anglicus n. sp., from the Upper Devonian of the North Devon Basin, Devon, UK. This is the first Devonian Hyattechinus known from outside of the Appalachian Basin, USA, and provides novel information regarding the palaeogeographic and stratigraphic distribution of proterocidarids in Late Devonian times. We additionally update the stratigraphic distribution of Devonian Hyattechinus from the Appalachian Basin, following recent biostratigraphic resolution of their occurrences. Hyattechinus appears to have been present in the Rheic echinoderm fauna during Late Devonian times, and comparison of the palaeoenvironmental setting of Hyattechinus anglicus with that of other Hyattechinus from the Famennian of the Appalachian Basin suggests that the genus may have preferred siliciclastic settings. Furthermore, this new taxon increases the diversity of echinoids from the Upper Devonian of Devon to three species.
Siphonophores are colonial hydrozoans that feed on zooplankton including fish larvae, and occur throughout the world's oceans from surface waters to ocean depths. Here we describe the composition of hyponeustonic siphonophores (0–3 m depth) from the tropical Colombian Pacific Ocean based on 131 plankton samples collected between June–October from 2001–2004. Samples were dominated by species of Calycophorae, with only three species of Physonectae identified, consistent with their deeper depth distribution. Muggiaea atlantica, Chelophyes contorta, Diphyes dispar, and Eudoxoides mitra were the most common of the 21 species identified. We found moderate structuring of the siphonophore community by the salinity gradient from inshore to offshore, and greater richness during the night because of diel vertical migration. Temperature did not play a significant role in structuring siphonophore communities, perhaps because of the narrow temperature range observed (3.5 °C). We extend the known temperature and salinity range of several species, including M. atlantica up to temperatures of 28.6 °C and salinities down to 24.7. Interestingly, only polygastric stages of M. atlantica were found, suggesting the reproductive stage of M. atlantica in tropical waters might be found in deeper waters. Chelophyes appendiculata was rare in our study and C. contorta was common, providing evidence they have a potential allopatric relationship, with C. contorta replacing C. appendiculata in warm water. Finally, we found siphonophore abundance was positively related to the abundance of copepods and fish eggs, with the top 13 most abundant species all having positive correlations, suggesting siphonophore abundances are tightly controlled by their food.
Mitochondrial and nuclear sequence data from two Antarctic ameronothroid mites, Halozetes belgicae and Alaskozetes antarcticus, were used to address three key questions important for understanding both the evolution of biodiversity and its future conservation in the Antarctic Peninsula Region: i) Do populations of mites across the Antarctic Peninsula and Scotia Arc constitute distinct genetic lineages? ii) What implications does the spatial genetic structure in these species have for current understanding of the region’s glacial history? iii) What are the conservation implications of these findings? Our results indicate that both mite species have been present in the Antarctic since at least the Pliocene. At the regional scale, both species are comprised of a number of divergent, but sympatric, lineages that are genetically as distinct as some species within the genera Halozetes and Alaskozetes. At the local scale, complex structure suggests limited and stochastic post-Holocene dispersal. For both species, considerable spatial genetic structure exists across the region, similar to that found in other terrestrial invertebrates. These results support the implementation of stringent biosecurity measures for moving between the Scotia Arc islands and the Antarctic Peninsula, and throughout the latter, to conserve both evolutionary history and future evolutionary trajectories.
This paper concerns itself with the contributions that the Humanities make to the understanding of islands and their bettered environmental conservation. Most distinctively, the Humanities comprise Literary Studies, Studies in Art and Culture (including Indigenous and Gender Studies) and Philosophy (with Aesthetics and the History of Ideas), but they also encompass Archaeology, History, Linguistics, Studies in Religion and, of late, Media and Communication Studies, even though members of this latter cluster frequently deploy methods from the social sciences. The goal here is to explore many of the implications such Human Studies and their sub-branches may have for island conservation, above all informed by the History of Ideas, in order to introduce the relevant key issues and inter-relationships and offer the most judicious illustrative materials. Variances in the reach and special attention of all these branches of knowledge are vast and intricate, while complex relativities apply both in the types of island situations and in expectations about what can or should be conserved. Since the mass of apposite discussions in the literature cannot possibly be summarized here, this article circumvents the difficulties by means of a special double-edged review. It ranges over the history of human consciousness of insular worlds, as reflected in mythic, legendary and historical materials, yet en route it uncovers how Humanities research can elucidate the human responses to islands through known time and shows how developing meaning-making has generally enhanced the appeal of sea-locked environments as worth conserving.