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1.
TOVE H. JORGENSEN JENS M. OLESEN 《Botanical journal of the Linnean Society. Linnean Society of London》2000,132(3):223-240
Growth forms of 22 species of Aeonium (Crassulaceae) were quantified. Since all species are simple in their modular construction, models were developed to predict module length, branching mode and flowering probability using linear and logistic regression. When combined, the parameters of these models are species specific. A discriminant analysis generates a statistically significant separation of species at the level of phylogenetic sections. The results therefore demonstrate the phylogenetic value of growth rules in plants. This dynamic approach strongly contrasts with the traditional static view on forms in systematics and morphology. It also leaves scope for predicting the evolutionary pathways of morphological change which have caused the great diversity of growth forms in the genus Aeonium. 相似文献
2.
HENRIK ENGHOFF 《Biological journal of the Linnean Society. Linnean Society of London》1992,46(1-2):153-161
Endemic species swarms constitute large fractions of the millipede faunas of Madeira (29 species of the Cylindroiulus madeirae group, plus six species of Acipes , out of a total of 60 species) and the Canary Islands (46 species of Dolichoiulus , plus four species of the Glomeris alluaudi-group , out of a total of about 79 species). The poorer faunas of the Azores (22 species) and the Cape Verde Islands (15 species) in contrast only include a few endemics. The Cylindroiulus madeirae group and Dolichoiulus show a high degree of diversity of structure (size, colour, leg length etc.) and habitat (laurisilva, xeric habitats, caves). The C. madeirae group, unlike Dolichoiulus , is strongly concentrated in the laurisilva. In this habitat, microhabitat differentiation is pronounced in both swarms. 相似文献
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Scalibregmatidae is a small annelid family of subsurface deposit feeders in sand or mud, which are generally well adapted to infaunal burrowing. The overall morphology of Scalibregmatidae is very similar, with thick bodies, small parapodia, and no prostomial appendages or short horns. The only exception is members of the genera Axiokebuita and Speleobregma that most frequently inhabit crevices or gravel and possess extensive ventral ciliated palps and globular adhesive pygidium. Character reconstruction using maximum likelihood and Bayesian methods show that ciliated palps and adhesive pygidium are synapomorphies of the Axiokebuita–Speleobregma clade. The most likely transformation series is from horns to ciliated palps, the origin of which correlates with the occurrence of Axiokebuita and Speleobregma in crevices or gravel. The wide spaces among rocks or granules yield high permeability and inertial water flow, preventing deposition of organic matter. Under these flow conditions that differ significantly from those of sand or mud bottom, ciliated palps aid to the collection of suspended particles and an adhesive pygidium provides attachment. With palps being a highly debated character in annelid evolution, it is remarkable that prominent ciliated palps are gained within a lineage of ancestrally nonpalpate annelids, most likely increasing their fitness when colonizing a new environment. 相似文献
5.
Gillespie RG Claridge EM Goodacre SL 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2008,363(1508):3335-3346
The islands of French Polynesia cover an area the size of Europe, though total land area is smaller than Rhode Island. Each hot spot archipelago (Societies, Marquesas, Australs) is chronologically arranged. With the advent of molecular techniques, relatively precise estimations of timing and source of colonization have become feasible. We compile data for the region, first examining colonization (some lineages dispersed from the west, others from the east). Within archipelagos, blackflies (Simulium) provide the best example of adaptive radiation in the Societies, though a similar radiation occurs in weevils (Rhyncogonus). Both lineages indicate that Tahiti hosts the highest diversity. The more remote Marquesas show clear examples of adaptive radiation in birds, arthropods and snails. The Austral Islands, though generally depauperate, host astonishing diversity on the single island of Rapa, while lineages on other islands are generally widespread but with large genetic distances between islands. More recent human colonization has changed the face of Polynesian biogeography. Molecular markers highlight the rapidity of Polynesian human (plus commensal) migrations and the importance of admixture from other populations during the period of prehistoric human voyages. However, recent increase in traffic has brought many new, invasive species to the region, with the future of the indigenous biota uncertain. 相似文献
6.
We describe 10 polymorphic tetranucleotide microsatellite loci from the eastern Canary Island lacertid lizard, Gallotia atlantica. Loci were isolated from a partial genomic library that had been enriched for AAAG repeat sequence. All loci were highly polymorphic (eight alleles or more) with observed heterozygosities from 0.75 to 1.00. At least four loci were successfully amplified and polymorphic in the Gran Canarian lacertid, Gallotia stehlini. These loci will be used to examine correlations between patterns of gene flow and recent volcanism on the island of Lanzarote. 相似文献
7.
DENIS F. OWEN F.L.S. DAVID A. S. SMITH F.L.S. 《Biological journal of the Linnean Society. Linnean Society of London》1993,49(4):355-365
A sample of 2013 meadow brown butterflies, Maniola jurtina , was obtained in the Algarve, southern Portugal, on behalf of E.B. Ford, the founder of ecological genetics. Variation in the meadow brown occupied Ford's attention for more than 40 years. Ford died in 1988; most of his collection had earlier been destroyed, but the meadow browns remained and became available for analysis. The butterflies were scored for spotting characters on both fore- and hindwings. The population is homogeneous over the entire area of the Algarve and there is no conclusive evidence of a difference between the two years of collection (1986 and 1987). It is probably also homogeneous with southern Iberia in general, an area unique in the western Palaearctic range of the species as it is characterized by a high spot average in males and a low spot average in females. Algarve butterflies differ markedly from those of the Canary Islands, where there is considerable inter-island heterogeneity, supporting the view that the Canary Island populations did not originate from southern Iberia. In the Algarve, many females aestivate and by September there is an essentially all-female population. These are low-spotted and differ significantly from females active in May and June at the start of the annual (one generation) flight season. 相似文献
8.
Martin Haase Carola Greve Rainer Hutterer Bernhard Misof 《Zoological Journal of the Linnean Society》2014,171(1):92-107
Time‐trees are commonly calibrated based on fossils attributed to internal nodes, thus defining the minimum age of these nodes. However, in the absence of synapomorphies, the phylogenetic position of a fossil can only be inferred based on similarity. In this study, we objectively allocated fossil shells to internal nodes based on the reconstruction of ancestral shapes and sizes in a geometric morphometric framework. Our phylogenetic analysis of 24 (putative sub)species was based on 2524 amplified fragment length polymorphism loci. In this well‐supported tree the taxa occurring in north‐west Africa and on the Iberian peninsula were paraphyletic with respect to the (sub)species from the Canary and Selvagen Islands, indicating a continental origin of the genus in contrast to our earlier sequence‐based account. Ancestral shell shapes and sizes were inferred based on landmark data using squared‐change parsimony. In a subsequent principal component analysis, only three of 20 fossil shells could be unequivocally allocated to internal nodes. However, these fossils were all Quaternary, and thus too young to infer meaningfully narrow confidence intervals for divergence estimates that probably reach back into the Miocene or even Oligocene. The apparent failure of allocating older fossils to internal nodes and achieving a reliable tree calibration was caused by the absence of phylogenetic signal in the shells of Theba due to extensive, sometimes rapid, convergent evolution, including reversals. © 2014 The Linnean Society of London 相似文献
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AGUEDO MARRERO RAFAEL S. ALMEIDA MANUEL GONZÁLEZ-MARTÍN 《Botanical journal of the Linnean Society. Linnean Society of London》1998,128(3):291-314
The arborescent taxa of Dracaena which form the dragon tree group comprise five species found in Macaronesia, Morocco (D. draco), East Africa (D. ombet, D. schizantha), Arabia (D. serrulata) and the island of Socotra (D. cinnabari). A new species of dragon tree, Dracaena tamaranae A. Marrero, R. S. Almeida & M. Gonzalez-Martin, is described from Gran Canaria, Canary Islands. This new species differs from D. draco, the only other Dracaena species currently known in Macaronesia, in having a growth form and inflorescence type and leaves more similar to the East African and Arabian species of Dracaena. In contrast, D. draco appears to be related to D. cinnabari. In this paper, we also present a study of the taxonomy, habitat and ecology of all the species of the dragon tree group. These are found in thermo-sclerophyllous plant communities of tropical-subtropical regions which are rather xerophilous and have a rainfall range of 200–500 mm. Our study indicates two independent colonization events for Dracaena in Macaronesia. In addition, we suggest that the dragon tree group provides an example of two major biogeographical disjunctions between East and West Africa. We postulate that this group has a Tethyan origin, a hypothesis supported by fossil and palaeoclimatic data, and thus parallels the distribution and dispersal pattern of other taxonomic groups. 相似文献
11.
A. Traveset M. Nogales J. A. Alcover J. D. Delgado M. López-Darias D. Godoy J. M. Igual P. Bover 《Biological invasions》2009,11(7):1653-1670
Invasions of alien rodents have shown to have devastating effects on insular ecosystems. Here we review the ecological impacts
of these species on the biodiversity of the Balearic and the Canary Islands. A total of seven species of introduced rodents
(two rats, three mice, one dormouse, and one squirrel) have been recorded (six in the Balearics and four in the Canaries).
Some of them can occasionally be important predators of nesting seabirds, contributing to the decline of endangered populations
in both archipelagos. Rats are also known to prey upon terrestrial birds, such as the two endemic Canarian pigeons. Furthermore,
rats actively consume both vegetative and reproductive tissues of a high number of plants, with potential relevant indirect
effects on vegetation by increasing erosion and favoring the establishment of alien plants. In the Balearics, rats and mice
are important seed predators of endemic species and of some plants with a restricted distribution. In the Canaries, rats intensively
prey upon about half of the fleshy-fruited tree species of the laurel forest, including some endemics. In both archipelagos,
alien rodents disrupt native plant–seed dispersal mutualisms, potentially reducing the chances of plant recruitment at the
same time that they modify the structure of plant communities. We further suggest that alien rodents played (and play) a key
role in the past and present transformation of Balearic and Canarian native ecosystems. 相似文献
12.
RAINER HUTTERER TIZIANO MADDALENA OBDULIA M. MOLINA 《Biological journal of the Linnean Society. Linnean Society of London》1992,46(1-2):49-58
Until recently the North Atlantic Islands were believed to house only mammals introduced by humans. Recent work has demonstrated that at least the Canary Islands house(d) a native mammal fauna. New data including chromosome numbers, genetic distances and analysis of vocalizations are given for the two extant shrew species, Crocidura canariensis and C. osorio , and their possible sister taxa are evaluated. Evidence is presented for the hypothesis that the two island species originated from two different lineages of the Palaearctic branch of the genus Crocidura. The data support the present status of the Canary Island shrews as local endemics of high conservation priority. 相似文献
13.
Martin Stervander Juan Carlos Illera Laura Kvist Pedro Barbosa Naomi P. Keehnen Peter Pruisscher Staffan Bensch Bengt Hansson 《Molecular ecology》2015,24(10):2477-2494
Isolated islands and their often unique biota continue to play key roles for understanding the importance of drift, genetic variation and adaptation in the process of population differentiation and speciation. One island system that has inspired and intrigued evolutionary biologists is the blue tit complex (Cyanistes spp.) in Europe and Africa, in particular the complex evolutionary history of the multiple genetically distinct taxa of the Canary Islands. Understanding Afrocanarian colonization events is of particular importance because of recent unconventional suggestions that these island populations acted as source of the widespread population in mainland Africa. We investigated the relationship between mainland and island blue tits using a combination of Sanger sequencing at a population level (20 loci; 12 500 nucleotides) and next‐generation sequencing of single population representatives (>3 200 000 nucleotides), analysed in coalescence and phylogenetic frameworks. We found (i) that Afrocanarian blue tits are monophyletic and represent four major clades, (ii) that the blue tit complex has a continental origin and that the Canary Islands were colonized three times, (iii) that all island populations have low genetic variation, indicating low long‐term effective population sizes and (iv) that populations on La Palma and in Libya represent relicts of an ancestral North African population. Further, demographic reconstructions revealed (v) that the Canary Islands, conforming to traditional views, hold sink populations, which have not served as source for back colonization of the African mainland. Our study demonstrates the importance of complete taxon sampling and an extensive multimarker study design to obtain robust phylogeographical inferences. 相似文献
14.
J. A. MATEO L. F. LOPEZ-JURADO 《Biological journal of the Linnean Society. Linnean Society of London》1992,46(1-2):39-48
The dentition of Gallotia stehlini from one extant and two subfossil populations dated as 4000 and 2000 years before present was studied. Body measurements were similar in the two subfossil populations, but much greater than the largest sizes observed today in G. stehlini. The morphology of the dental cusps in this G. stehlini differs greatly from that of other Lacertidae, including other congeneric Canarian species; this has been connected with a vegetarian diet. A decrease in heterodonty with size of the animal is also seen which contrasts strongly with the models observed in the Mediterranean lacertid lizards. 相似文献
15.
Aim The aim of this paper is to investigate the causes of the current restricted distribution of a narrow-range endemic bird species, the Canary Islands stonechat, Saxicola dacotiae .
Location Eastern islands of the Canary Islands archipelago.
Methods We compared climatic patterns (temperature and rainfall), habitat and microhabitat structure, food availability during a full annual cycle, and the abundance of native avian competitors and predators inside and outside the species' range. Three study areas, located in similar habitats on nearby islands, were studied: northern Fuerteventura, close to the northern border of the species' range; southern Lanzarote, 22 km from the nearest site occupied by stonechats; and the Lobos islet, 10 km from the nearest occupied site and 2 km from the coast of Fuerteventura.
Results The cover of suitable habitats (slopes with high cover of large shrubs, stony fields and ravines) and microhabitats (shrubs and boulders) and the abundance of arthropods during the breeding period of Canary Islands stonechats were lower outside than inside the species' range. Temperature, rainfall and the abundance of competitors and predators inside and outside the species' range did not differ significantly.
Main conclusions Ecological requirements explaining the distribution of the Canary Islands stonechat within its range seem to be the main factor hindering its settlement on nearby islands. Geological and palaeoclimatic processes, as well as past and current human impact, could also have constrained the distribution of this narrow-range endemic bird species. 相似文献
Location Eastern islands of the Canary Islands archipelago.
Methods We compared climatic patterns (temperature and rainfall), habitat and microhabitat structure, food availability during a full annual cycle, and the abundance of native avian competitors and predators inside and outside the species' range. Three study areas, located in similar habitats on nearby islands, were studied: northern Fuerteventura, close to the northern border of the species' range; southern Lanzarote, 22 km from the nearest site occupied by stonechats; and the Lobos islet, 10 km from the nearest occupied site and 2 km from the coast of Fuerteventura.
Results The cover of suitable habitats (slopes with high cover of large shrubs, stony fields and ravines) and microhabitats (shrubs and boulders) and the abundance of arthropods during the breeding period of Canary Islands stonechats were lower outside than inside the species' range. Temperature, rainfall and the abundance of competitors and predators inside and outside the species' range did not differ significantly.
Main conclusions Ecological requirements explaining the distribution of the Canary Islands stonechat within its range seem to be the main factor hindering its settlement on nearby islands. Geological and palaeoclimatic processes, as well as past and current human impact, could also have constrained the distribution of this narrow-range endemic bird species. 相似文献
16.
Wing polymorphism has been reported for several carabid beetles. Traditionally, a great number of ecological and evolutionary studies have focused on this peculiarity, which has implications on dispersal power. Research based on Orthomus berytensis specimens from two sampling areas of Tenerife (Canary Islands, Spain) has shown that this species exhibits a wing dimorphism, instead of being brachypterous. This makes O. berytensis the first Orthomus wing dimorphic species to date. Statistical differences in macropterous percentage between both sexes and localities were found. Also, a sexual dimorphism in elytra length and width was found, both being higher in females. 相似文献
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Motomi Ito 《Population Ecology》1998,40(2):205-212
The Bonin Islands are typical oceanic islands, located at the western part of the North Pacific Ocean and approximately 1,000 km south of mainland Japan. This archipelago consists of about 20 small islands. Although floristic diversity is low due to the small area and limited environmental diversity, the Bonin Islands harbor unique endemic flora as in other well-known oceanic islands. This paper presents a brief summary of the results obtained from recent studies on the endemic flora of the Bonin Islands. The results are reviewed in relation to the four stages of the evolution of endemic flora in the oceanic islands; migration, establishment, enlargement and diversification. The ancestors of the flora originated mostly from tropical and subtropical Southeast Asia or mainland Japan by rare events of long distance dispersal. The proportion of bird-dispersed species is relatively high as for other oceanic islands. Genetic data sets obtained from allozyme variation in some endemic species suggest that migration occurred several million years ago and genetic diversity is correlated with current population size. At the time of establishment, self-compatible plants are expected to have an advantage. However, the percentage of dioecious plants is relatively high. This is partly due to evolutionary changes from hermaphroditic ancestors to dioecy which occurred in two genera in the Bonin Islands. In addition, there are some examples of evolutionary changes from herbaceous ancestors to woody endemics. Adaptive radiation is found in some genera, although the number of congeneric endemic species is less than five. Studies of allozyme variation inPittosporum, Symplocos andCrepidiastrum showed that genetic identity is generally very high between congeneric species in spite of their distinct morphologies. This result suggests that divergence of these species occurred rather recently and distinct morphological differences are based on a limited number of genetic changes. 相似文献
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《Journal of bryology》2013,35(2):154-157
AbstractWe revised both the holotype and an isotype of Riccia teneriffae S.W.Arnell 1962 and additionally revised our own collections of Riccia cavernosa Hoffm. 1795 from the Canary Islands. Since the types of R. teneriffae represent R. cavernosa, and the latter name precedes the former, R. teneriffae should be treated as a synonym of R. cavernosa. In the Canary Islands, R. cavernosa appears to be rare. It has been found on La Gomera, Gran Canaria, Lanzarote, and Tenerife. We report it as new to Fuerteventura. R. cavernosa inhabits ephemeral, thin layers of mud. Very rarely it occurs on basaltic pyroclasts. SEM images of spores are presented. The local distribution is mapped. 相似文献
20.
Maca-Meyer N Cabrera VM Arnay M Flores C Fregel R González AM Larruga JM 《American journal of physical anthropology》2005,127(4):418-426
Mitochondrial DNA sequences and restriction fragment length polymorphisms were retrieved (with >80% efficiency) from a 17th-18th century sample of 213 teeth from Tenerife. The genetic composition of this population reveals an important ethnic heterogeneity. Although the majority of detected haplotypes are of European origin, the high frequency of sub-Saharan African haplotypes (15.63%), compared to that of the present-day population (6.6%), confirms the importance of the Canary Islands in the black slave trade of that epoch. The aboriginal substrate, inferred from the U6b1 haplotypes (8.59%), has also decreased due to European input. Finally, the presence of Amerindian lineages (1.5%) reveals that the Canary Islands have also received genetic flow from America. 相似文献