Tertiary Origin Research Articles

Coal Waste Dumping, Mine Reclamation and Pit Lake Management in the Open Cast Mines of Tikak and Tirap Colliery, Tinsukia District, Assam, India

Coal or black gold usually occurs in layers known as coal seams. The coal reserves of India are of tertiary origin and are of peat, sub-bituminous and bituminous nature. The Tirap and Tikak coalfields are the largest coalfields of Ledo-Margherita area in the District of Tinsukia. While Tikak coalfield is operational, Tirap has been closed on environmental grounds. Both the coalfields have undergone the activity of mine reclamation and pit lake formation. Coal waste mountains extensively mark the landscape. The Rat-Hole mining is also operational in the area resulting in illegal mining and unpredictable fires due to oxidation and release of poisonous gases. Deliberate efforts by the mining authorities have been seen in the management of the mines. The process of mine reclamation has already begun in both the coalfields and there has been a significant transformation after the plantations took place. The barren lands are planted once the mining gets completed for the zone. A unique feature of surface mine is the presence of pit lakes. They are the lakes formed in the depressions caused by mining and often coincide with the level of the ground water table. These lakes are filled with ground water, precipitation, water from mountains and other surface run-off. They have high potential in serving the aquatic needs of nearby communities, recreation and provides home to flora and fauna if taken utmost care of. Case study approach has been chosen to understand the sustainability efforts of the mines. The effectiveness of mine reclamation has been studied to understand its present and future benefits. Pit lakes and its role in aquatic sustainability have been analyzed as they are basically created and regulated to mitigate environmental impacts from mining operations. Pit lakes are being seen as an important site to have its inclusion in the Ramsar list in India. These efforts are leading its way towards green mines and sustainability.

An integrative approach supports the taxonomic distinction of the Sardo-Corsican endemic Euphorbia semiperfoliata from the widespread E. amygdaloides (Euphorbiaceae)

In the western Mediterranean, Corsica and Sardinia are characterised by high plant diversity and endemism, and exhibit a tight biogeographic connection. One of the endemic taxa thriving in forests, macchia, along riversides and in mountain grasslands of both islands is Euphorbia semiperfoliata. It was often considered a subspecies of the widespread European forest plant Euphorbia amygdaloides, or deemed closely related with the western Asian E. macroceras and E. oblongifolia. Here, we explored the evolutionary origin of E. semiperfoliata using nuclear ITS sequences that showed that E. semiperfoliata is divergent from E. amygdaloides and the other species of E. sect. Patellares, which indicates its old, likely Tertiary origin. In addition, its relative genome size is different from E. amygdaloides and other species and several morphological characters revealed by morphometric analyses differentiate E. semiperfoliata from E. amygdaloides. Finally, we provide a taxonomic treatment for E. semiperfoliata, including the typification and a morphological description.

Phylogeographical Analyses of a Relict Fern of Palaeotropical Flora (Vandenboschia speciosa): Distribution and Diversity Model in Relation to the Geological and Climate Events of the Late Miocene and Early Pliocene.

Fern phylogeographic studies have mostly focused on the influence of the Pleistocene climate on fern distributions and the prevalence of long-distance dispersal. The effect of pre-Pleistocene events on the distributions of fern species is largely unexplored. Here, we elucidate a hypothetical scenario for the evolutionary history of Vandenboschia speciosa, hypothesised to be of Tertiary palaeotropical flora with a peculiar perennial gametophyte. We sequenced 40 populations across the species range in one plastid region and two variants of the nuclear gapCp gene and conducted time-calibrated phylogenetic, phylogeographical, and species distribution modelling analyses. Vandenboschia speciosa is an allopolyploid and had a Tertiary origin. Late Miocene aridification possibly caused the long persistence in independent refugia on the Eurosiberian Atlantic and Mediterranean coasts, with the independent evolution of gene pools resulting in two evolutionary units. The Cantabrian Cornice, a major refugium, could also be a secondary contact zone during Quaternary glacial cycles. Central European populations resulted from multiple post-glacial, long-distance dispersals. Vandenboschia speciosa reached Macaronesia during the Pliocene–Pleistocene, with a phylogeographical link between the Canary Islands, Madeira, and southern Iberia, and between the Azores and northwestern Europe. Our results support the idea that the geological and climate events of the Late Miocene/Early Pliocene shifted Tertiary fern distribution patterns in Europe.

Macaronesia Acts as a Museum of Genetic Diversity of Relict Ferns: The Case of Diplazium caudatum (Athyriaceae).

Macaronesia has been considered a refuge region of the formerly widespread subtropical lauroid flora that lived in Southern Europe during the Tertiary. The study of relict angiosperms has shown that Macaronesian relict taxa preserve genetic variation and revealed general patterns of colonization and dispersal. However, information on the conservation of genetic diversity and range dynamics rapidly diminishes when referring to pteridophytes, despite their dominance of the herbaceous stratum in the European tropical palaeoflora. Here we aim to elucidate the pattern of genetic diversity and phylogeography of Diplazium caudatum, a hypothesized species of the Tertiary Palaeotropical flora and currently with its populations restricted across Macaronesia and disjunctly in the Sierras de Algeciras (Andalusia, southern Iberian Peninsula). We analysed 12 populations across the species range using eight microsatellite loci, sequences of a region of plastid DNA, and carry out species-distribution modelling analyses. Our dating results confirm the Tertiary origin of this species. The Macaronesian archipelagos served as a refuge during at least the Quaternary glacial cycles, where populations of D. caudatum preserved higher levels of genetic variation than mainland populations. Our data suggest the disappearance of the species in the continent and the subsequent recolonization from Macaronesia. The results of the AMOVA analysis and the indices of clonal diversity and linkage disequilibrium suggest that D. caudatum is a species in which inter-gametophytic outcrossing predominates, and that in the Andalusian populations there was a shift in mating system toward increased inbreeding and/or clonality. The model that best explains the genetic diversity distribution pattern observed in Macaronesia is, the initial and recurrent colonization between islands and archipelagos and the relatively recent diversification of restricted area lineages, probably due to the decrease of favorable habitats and competition with lineages previously established. This study extends to ferns the concept of Macaronesia archipelagos as refugia for genetic variation.

Are there any Tertiary relict species in the modern Bulgarian spider fauna (Arachnida: Araneae)?

The species classified by various authors as Tertiary relics in the Bulgarian spider fauna are reviewed. The classification criteria used by previous authors are evaluated and discussed, and an attempt is made to identify the zoogeographical status of these species. Based upon the arguments presented below, it can be concluded that the existence of spider species with Tertiary origin in the modern Bulgarian spider fauna is highly doubtful.

Spatio-temporal formation of the genetic diversity in the Mediterranean dwelling lichen during the Neogene and Quaternary epochs

Genetic patterns of lichenized fungi often display a mosaic-like and difficult to interpret structure blurring their evolutionary history. The genetic diversity and phylogeographic pattern of a mycobiont of the predominantly Mediterranean dwelling lichen Solenopsora candicans were investigated on the base of extensive sampling (361 individuals, 77 populations) across its entire distribution range. We tested whether the genetic pattern of S. candicans mirrors paleoclimatic and paleogeological events in the Mediterranean and adjacent regions. The divergence time estimates indicated a Tertiary origin for S. candicans, with formation of intraspecific diversity initiated in the Late Miocene. The distribution of the most divergent haplotypes, mostly of a pre-Pleistocene origin, was restricted to the eastern or western extremities of the Mediterranean exhibiting Kiermack disjunction. The population genetic diversity analyses indicated multiple diversity centres and refugia for S. candicans across the entire Mediterranean Basin. While the south Mediterranean regions harboured both the Tertiary and Quaternary born diversity, conforming to the ‘cumulative refugia’ paradigm, the Apennine and Balkan Peninsulas in the north hosted mostly younger Pleistocene haplotypes and lineages. The recent population expansion of S. candicans might have occurred in the middle Pleistocene with a population burst in the Apennine and Balkan peninsulas. The presence of unique haplotypes in Central Europe indicates the existence of extra-Mediterranean microrefugia. This study presents the first comprehensive lichen phylogeography from the Mediterranean region and simultaneously reports for the first time the glacial survival of a warm-adapted lichen in the temperate zone.

Divergence history and hydrothermal vent adaptation of decapod crustaceans: A mitogenomic perspective.

Decapod crustaceans, such as alvinocaridid shrimps, bythograeid crabs and galatheid squat lobsters are important fauna in the hydrothermal vents and have well adapted to hydrothermal vent environments. In this study, eighteen mitochondrial genomes (mitogenomes) of hydrothermal vent decapods were used to explore the evolutionary history and their adaptation to the hydrothermal vent habitats. BI and ML algorithms produced consistent phylogeny for Decapoda. The phylogenetic relationship revealed more evolved positions for all the hydrothermal vent groups, indicating they migrated from non-vent environments, instead of the remnants of ancient hydrothermal vent species, which support the extinction/repopulation hypothesis. The divergence time estimation on the Alvinocarididae, Bythograeidae and Galatheoidea nodes are located at 75.20, 56.44 and 47.41–50.43 Ma, respectively, which refers to the Late Cretaceous origin of alvinocaridid shrimps and the Early Tertiary origin of bythograeid crabs and galatheid squat lobsters. These origin stories are thought to associate with the global deep-water anoxic/dysoxic events. Total eleven positively selected sites were detected in the mitochondrial OXPHOS genes of three lineages of hydrothermal vent decapods, suggesting a link between hydrothermal vent adaption and OXPHOS molecular biology in decapods. This study adds to the understanding of the link between mitogenome evolution and ecological adaptation to hydrothermal vent habitats in decapods.

Comparative plastid genomics of Synurophyceae: inverted repeat dynamics and gene content variation

BackgroundThe Synurophyceae is one of most important photosynthetic stramenopile algal lineages in freshwater ecosystems. They are characterized by siliceous scales covering the cell or colony surface and possess plastids of red-algal secondary or tertiary endosymbiotic origin. Despite their ecological and evolutionary significance, the relationships amongst extant Synurophyceae are unclear, as is their relationship to most other stramenopiles.ResultsHere we report a comparative analysis of plastid genomes sequenced from five representative synurophycean algae. Most of these plastid genomes are highly conserved with respect to genome structure and coding capacity, with the exception of gene re-arrangements and partial duplications at the boundary of the inverted repeat and single-copy regions. Several lineage-specific gene loss/gain events and intron insertions were detected (e.g., cemA, dnaB, syfB, and trnL).ConclusionsUnexpectedly, the cemA gene of Synurophyceae shows a strong relationship with sequences from members of the green-algal lineage, suggesting the occurrence of a lateral gene transfer event. Using a molecular clock approach based on silica fossil record data, we infer the timing of genome re-arrangement and gene gain/loss events in the plastid genomes of Synurophyceae.

Phylogeny and biogeography of the narrowly endemic Doronicum cataractarum (Asteraceae) from the eastern European Alps: Pleistocene origin from Alpine ancestors rather than Tertiary relic with southwest Asian affinity

Distribution areas of narrowly endemic species in the European Alps often coincide with Pleistocene refugia, suggesting that allopatric divergence due to Pleistocene range shifts might have been instrumental in their origin. Here, we infer the phylogenetic position of the locally endemic Doronicum cataractarum testing previous hypotheses with respect to its biogeographic and temporal origin (Tertiary origin with southwest Asian affinities versus possibly Pleistocene origin in the Alps). To this end, we extended existing genus-wide data sets of nuclear and plastid DNA sequences and obtained sequences from two hitherto not used low copy nuclear markers. These data sets were analyzed, as single markers and jointly in a concatenated matrix, using maximum parsimony and maximum likelihood. Temporal and spatial origins of D. cataractarum were inferred using mean path lengths and dispersal–vicariance analysis, respectively. Phylogenetic resolution was limited, but several geographically coherent groups were identified, including the Grandiflora group comprising southern and central European mountain species. Congruently, D. cataractarum was inferred as most closely related to Alpine species from the Grandiflora group (D. clusii, D. stiriacum and D. glaciale), but neither to southwest Asian species nor to European D. austriacum. The origin of D. cataractarum was conservatively dated to about 1.9 Mya and inferred to have taken place in the Alps. The striking morphological differences between D. cataractarum and the most closely related species likely are the result of adaptation to different habitats or, alternatively, the presence of plesiomorphic traits in D. cataractarum.

Phylogenetic and biogeographic insights into long-lived Mediterranean Cupressus taxa with a schizo-endemic distribution and Tertiary origin

This work was supported by the National Science Centre [NCN, Contr. Number DEC-2012/07/N/NZ8/01287].

Why Teachers Assign Socially Unequal Marks. A Case for Establishing Tertiary Origin Effects in the Model of Primary and Secondary Effects of Educational Research

Subjective expected utility theory assumes that educational paths result from the interplay of primary effects – students’ cognitive skills – and secondary effects – academic decisions regarding their educational future. We argue that thus far, the assignment of marks has not been accounted for in the scope of Boudon’s model of primary and secondary effects. We propose an elaborated model in which psychological traits are included in the concept of primary effects and introduce a further component, tertiary effects, indicating teachers’ socially unequal assignment of marks. Empirically, we demonstrate that a specific psychological skill set has moderate influence on students’ marks, it does not, however, account for social inequalities in the assignment of marks. Nevertheless, our findings show that social differences in marks can almost entirely be explained by cognitive, psychological and resource-related tertiary effects. Furthermore, there is some evidence that the extent of tertiary effects is associated with the scholastic configuration of educational institutions. Lastly, we observe that teachers unknowingly overvalue children from higher social classes because they deem them more talented, more willing to achieve and better equipped with parental resources than children from lower social classes. A key question for future research is to find reasons for this biased perception. https://doi.org/10.26803/ijlter.17.7.1

The European PaleoendemicHaberlea rhodopensis(Gesneriaceae) Has an Oligocene Origin and a Pleistocene Diversification and Occurs in a Long-Persisting Refugial Area in Southeastern Europe

Premise of research. Even though the Balkan Peninsula is a biodiversity hot spot in southeastern Europe harboring many endemic plants, very little is known about the temporal extent of the phylogeographic history and the contemporary genetic diversity of the endemics there. Haberlea rhodopensis is one of the European Gesneriaceae species occurring in this region and represents appropriate study material to address these questions.Methodology. We generated fossil-dated molecular phylogenies (atpB-rbcL, trnH-psbA, trnLF, ITS) across the Lamiales to determine the origin and age of H. rhodopensis and conducted phylogeographic (trnH-psbA, ITS) and population genetic (ISSRs) analyses on 17 populations from Bulgaria and Greece, covering the entire distribution range of the species, to investigate their biogeographic history, present-day genetic diversity, and differentiation levels.Pivotal results. The European Gesneriaceae genera have a Tertiary origin in the early Oligocene, while the Haberlea lineage emerged in the late Oligocene. Extinctions appear to have marked the history of the genus for a long period of time, and the extant populations diverged in the late Pleistocene. A significant differentiation was apparent between populations from Bulgaria, that is, the Balkan Mountains in the north and the Bulgarian side of the Rhodopi massif in the south, but there was an even stronger differentiation between the latter and populations from Greece. This might be explained by the Rhodopi massif representing a barrier to gene flow, enforced during the Last Glacial Maximum, during which populations descended on opposing north- and south-facing mountain slopes.Conclusions. Haberlea represents an ancient lineage with recent diversification. The extant populations are of recent origin and indicate glacial refugial areas in Bulgaria and Greece. This study sheds light on historic and current phylogenetic and phylogeographic events that shaped the flora of the Balkan Peninsula, an area that has long been recognized for its species diversity and richness. Our data suggest that it may have acted as a persistent refugial area in southeast Europe since the mid-Tertiary.

Has Ever Brahmaea Ledereri Rogenhofer, 1873 Inhabited the Colchis Refugium

The biogeographical background. There are two refugial centers in Transcaucasia: Colchis (along the Black Sea coast) and Hyrcan (Hyrcania) (along the Caspian Sea shore). Elements from Europe and Asia and their biogeographical subdivisions compose flora and fauna, which combined with the diverse geomorphology (Laurasian, Gondvanian), the presence of the impressive mountain ridge of the Great Caucasus, its insularity during 100 million years (from Cretaceous time), have resulted in a high taxonomic (species, genera) richness and endemism. The both refugiais characterized by a rather uniform thermical indexes, considerably the former one. The both shelters consist of an extraordinary abundance and diversity of thermophilic woody flora (trees, shrubs and vines) belonging to Arcto-Tertiary Geoflora. Except species typical for nemoral biota, there are extremely rare species of tropical-subtropical origin, which became extinct in South Caucasus during the Tertiary (at the close of the Pliocene) climate deterioration. In response to cooling climate and physiographic changes, some rare genera became restricted to both refugia of Transcaucasia. Most of them are now confined chiefly within the Hyrcanianrefugium (species of Albizia, Gleditsia, Panthera, Hystrix). Among the invertebrate fauna of Tertiary origin should be considerably mentioned species of remarkable nocturnal Brahmin moth – Brahmaea Walker. The interdisciplinary study of the orthodox view regarding the vicariant event between two species of moths as thoughthey are indigenous of Colchis (B. ledereri) and Talysh (B. christophi) does not actually exist. The reason circumstances to express such opinion remain important due for a variety of reasons which are given below.

PHOLEUONOPSIS (PHOLEUONOPSIS) PERUCENSIS SP. N., A NEW TROGLOBITIC LEIODID BEETLE (COLEOPTERA: LEIODIDAE: CHOLEVINAE: LEPTODIRINI) FROM BOSNIA AND HERZEGOVINA

A new leptodirine beetle species, Pholeuonopsis (Pholeuonopsis) perucensis sp. n., from a cave in Eastern Bosnia and Herzegovina is both described and diagnosed. The structure of both male and female genitalia and other taxonomically important characters are imaged. The new beetle species is clearly distinct from all other congeners. It probably belongs to an old phyletic lineage of Tertiary origin, like other known Pholeuonopsis taxa from the Western Balkan Peninsula. The new species is both an endemic and a relict inhabiting solely Eastern Bosnia and Herzegovina.

The tertiary origin of the allosteric activation of E. coli glucosamine-6-phosphate deaminase studied by sol-gel nanoencapsulation of its T conformer.

The role of tertiary conformational changes associated to ligand binding was explored using the allosteric enzyme glucosamine-6-phosphate (GlcN6P) deaminase from Escherichia coli (EcGNPDA) as an experimental model. This is an enzyme of amino sugar catabolism that deaminates GlcN6P, giving fructose 6-phosphate and ammonia, and is allosterically activated by N-acetylglucosamine 6-phosphate (GlcNAc6P). We resorted to the nanoencapsulation of this enzyme in wet silica sol-gels for studying the role of intrasubunit local mobility in its allosteric activation under the suppression of quaternary transition. The gel-trapped enzyme lost its characteristic homotropic cooperativity while keeping its catalytic properties and the allosteric activation by GlcNAc6P. The nanoencapsulation keeps the enzyme in the T quaternary conformation, making possible the study of its allosteric activation under a condition that is not possible to attain in a soluble phase. The involved local transition was slowed down by nanoencapsulation, thus easing the fluorometric analysis of its relaxation kinetics, which revealed an induced-fit mechanism. The absence of cooperativity produced allosterically activated transitory states displaying velocity against substrate concentration curves with apparent negative cooperativity, due to the simultaneous presence of subunits with different substrate affinities. Reaction kinetics experiments performed at different tertiary conformational relaxation times also reveal the sequential nature of the allosteric activation. We assumed as a minimal model the existence of two tertiary states, t and r, of low and high affinity, respectively, for the substrate and the activator. By fitting the velocity-substrate curves as a linear combination of two hyperbolic functions with K t and K r as KM values, we obtained comparable values to those reported for the quaternary conformers in solution fitted to MWC model. These results are discussed in the background of the known crystallographic structures of T and R EcGNPDA conformers. These results are consistent with the postulates of the Tertiary Two-States (TTS) model.

A Sediment Sink for Possible Tertiary Aeolian Sediment in Galway Bay, Western Ireland

There is substantial evidence to suggest that Ireland during the Tertiary Period was subject to a period of intense chemical weathering. Two exposures illustrating this environment in western Ireland are described, adding to the known examples of this type of weathering elsewhere in Ireland. The surface features of quartz sand grains may be used to distinguish the environments through which they have passed during transport and deposition. Quartz grain surface features photographed by a scanning electron microscope are described from a sediment facies, ~ 10,000 years old, retrieved from cores taken from beneath the floor of Galway Bay. Many of these show the action of glacial activity by characteristic fracture patterns, as might be expected in Holocene sediment in an Irish context. Some of the grains, however, show features that suggest a prior aeolian component to their transport history. These grains are compared with quartz grains previously described and with the product of Tertiary Period weathering recovered from a sand pit at Pollnahallia, Co. Galway. Similarities suggest that some of the sand grains found at depths of ~2-5m beneath the substrate surface of Galway Bay may have originated from chemical weathering and aeolian transport during the late Tertiary Period and then been reworked in glacial and subsequent deltaic environments. Introduction limestone. The stratigraphy at this locality comprises a 5m-thick organic deposit (lignite) containing a Vestiges of Tertiary landscapes and sediments are Pliocene pollen assemblage, possibly up to the Plio still visible in Ireland, despite the subsequent eroPleistocene transition. The lignite is overlain by ~ 8m sional processes of the Pleistocene glacial advances of white silica sand, itself overlain by Pleistocene and retreats. Over 30 years ago, Mitchell (1980) lodgement till. Further details of the geology were proposed that some landforms of central and southpresented in Coxon et al. (2005) and Coxon (2005). ern Ireland were of Tertiary origin. In western Such evidence from western Ireland suggests a Ireland, Coxon (2005) has described buried tors in period during the Tertiary of intense chemical a granite terrain at Gowlaun East in Connemara. weathering of granite and possibly the Dalradian The tors are separated by weathered granite and a schists and metaquartzites of Connemara to pro palaeosol containing pollen that indicates dates of duce quartz-rich sands such as those fortuitously 2.6-5 million years ago (Coxon 2001a). At Pollnapreserved in the gorge at Pollnahallia. Such intense hallia, near Headford, Co. Galway (Fig. IB), Coxon chemical weathering has been recorded elsewhere, and Flegg (1987) described a quartz-rich sand for example, Scotland, during the Tertiary (e.g., Hall deposit situated in gorges and caves in Carboniferous 1991 ; Knox 2002). Irish Journal of Earth Sciences 30 (2012), 41-47 © 2012 Royal Irish Academy doi: 10.3318/1 JES.2012.30.41 41 This content downloaded from 207.46.13.156 on Sat, 10 Sep 2016 05:26:56 UTC All use subject to http://about.jstor.org/terms 42 Irish Journal of Earth Sciences (2012)

Phylogeny and evolutionary divergence times in Apterosperma and Euryodendron: Evidence of a Tertiary origin in south China

Abstract Apterosperma and Euryodendron, monotypic genera in Theaceae (sensu lato), are endemic and restrictedly distributed in south China. The two genera are not included in the major classification systems. However, their systematic position and origin have been subject to intense debate in the last decade. In this study, the phylogeny and divergence times of both Apterosperma and Euryodendron were inferred using combined dataset of chloroplast DNA trnL-F and atpB-rbcL non-coding sequences and nrDNA ITS sequences. The results from Bayesian inference, maximum parsimony, and maximum likelihood consistently showed that (i) Euryodendron is a valid genus, which is closer to Eurya than to Cleyera and (ii) Apterosperma is a genus of the tribe Theeae along with Tutcheria and Camellia. It was first reported that the divergence time of Apterosperma was 61.98 million years ago (mya), whereas that of Euryodendron 20.51 mya, indicating Tertiary origins in south China. The divergence of Apterosperma appears to be the result of increased ecological opportunity after Cretaceous/Tertiary extinction events and related with high temperatures and high humidity environments. By contrast, the origin of Euryodendron may be associated with historical mountain building events as well as the significant climate changes that established cooler temperatures prevailing until today.

Genome Evolution of a Tertiary Dinoflagellate Plastid

The dinoflagellates have repeatedly replaced their ancestral peridinin-plastid by plastids derived from a variety of algal lineages ranging from green algae to diatoms. Here, we have characterized the genome of a dinoflagellate plastid of tertiary origin in order to understand the evolutionary processes that have shaped the organelle since it was acquired as a symbiont cell. To address this, the genome of the haptophyte-derived plastid in Karlodinium veneficum was analyzed by Sanger sequencing of library clones and 454 pyrosequencing of plastid enriched DNA fractions. The sequences were assembled into a single contig of 143 kb, encoding 70 proteins, 3 rRNAs and a nearly full set of tRNAs. Comparative genomics revealed massive rearrangements and gene losses compared to the haptophyte plastid; only a small fraction of the gene clusters usually found in haptophytes as well as other types of plastids are present in K. veneficum. Despite the reduced number of genes, the K. veneficum plastid genome has retained a large size due to expanded intergenic regions. Some of the plastid genes are highly diverged and may be pseudogenes or subject to RNA editing. Gene losses and rearrangements are also features of the genomes of the peridinin-containing plastids, apicomplexa and Chromera, suggesting that the evolutionary processes that once shaped these plastids have occurred at multiple independent occasions over the history of the Alveolata.

Notodiscus (Charopidae) on South Georgia: some implications of shell size, shell shape, and site isolation in a singular sub-Antarctic land snail

AbstractMultivariate analysis shows that shells of Notodiscus sp. (Charopidae: Pulmonata) reported from South Georgia are smaller and proportionately taller than, but otherwise similar to, populations of Notodiscus hookeri (Reeve) from Iles Crozet and Iles Kerguelen. The origin of this solitary, and spatially limited, South Georgia population is enigmatic. It is confined to a remarkably small coastal lowland site which was glaciated at Last Glacial Maximum, precluding a Tertiary relict origin, and on the leeward north-east coast, ruling out post-glacial ocean rafting. The site is close to the King Edward Point settlement, yet the absence of any logistics connections with the Iles Crozet or Iles Kerguelen mitigates against anthropogenic introduction. The close proximity of the population to nests of blue-eyed shag (Phalacrocorax atriceps), Dominican gull (Larus dominicanus) and light-mantled sooty albatross (Phoebetria palpebrata) could imply the snail was originally introduced to South Georgia via these ocean transiting seabirds.

Why red‐dominated autumn leaves in America and yellow‐dominated autumn leaves in Northern Europe?

Why red‐dominated autumn leaves in America and yellow‐dominated autumn leaves in Northern Europe?