Coral biodiversity and evolution: recent molecular contributions

2002 ◽  
Vol 80 (10) ◽  
pp. 1723-1734 ◽  
Author(s):  
Uri Frank ◽  
Ofer Mokady
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Recent Literature ◽  
Morphological Characters ◽  
Reticulate Evolution ◽  
The Past ◽  
Tropical Reefs ◽  
New Concepts ◽  
Molecular Studies ◽  
The Subject

Tropical reefs are among the most diverse ecosystems. Corals, as the most prominent members and framework builders of these communities, deserve special attention, especially in light of the recent decline of coral reefs worldwide. The diversity of corals at various levels has been the subject of many studies, and has traditionally been investigated using morphological characters. This approach has proved insufficient, owing to several ecological and life-history traits of corals. The use of molecular/biochemical approaches has been propelling this discipline forward at an ever-increasing rate for the past decade or so. Reticulate evolution in corals, which has challenged traditional views on the ecology, evolution, and biodiversity of these organisms, is only one example of the results of molecular studies supporting the development of new concepts. We review recent literature reporting studies of the biodiversity, ecology, and evolution of corals in which molecular methods have been employed. We anticipate that in the coming years, an increasing number of studies in molecular biology will generate new and exciting ideas regarding the biology of corals.

scholarly journals Covariation between personalities and individual differences in coping with stress: Converging evidence and hypotheses

2010 ◽  
Vol 56 (6) ◽  
pp. 728-740 ◽  
Author(s):  
Claudio Carere ◽  
Doretta Caramaschi ◽  
Tim W. Fawcett
Keyword(s):  
Individual Differences ◽  
Life History Traits ◽  
Physiological Responses ◽  
Stress Physiology ◽  
Behavioural Ecology ◽  
Coping With Stress ◽  
The Past ◽  
Adaptive Value ◽  
The Subject ◽  
Working Hypotheses

Abstract In the past decade there has been a profusion of studies highlighting covariation between individual differences in stress physiology and behavioural profiles, here called personalities. Such individual differences in ways of coping with stress are relevant both in biomedicine, since different personalities may experience a different stress and disease vulnerability, and in behavioural ecology, since their adaptive value and evolutionary maintenance are the subject of debate. However, the precise way in which individual stress differences and personalities are linked is unclear. Here we provide an updated overview of this covariation across different species and taxa, consider its functional significance and present working hypotheses for how behavioural and physiological responses to stress might be causally linked, affecting life-history traits such as dispersal and life-span.

Mitochondrial cytochrome oxidase I in tetranychid mites: a comparison between molecular phylogeny and changes of morphological and life history traits

1996 ◽  
Vol 86 (4) ◽  
pp. 407-417 ◽  
Author(s):  
Maria Navajas ◽  
Jean Gutierrez ◽  
Jacques Lagnel ◽  
Pierre Boursot
Keyword(s):  
Life History ◽  
Cytochrome Oxidase ◽  
Life History Traits ◽  
Codon Position ◽  
Morphological Characters ◽  
Mitochondrial Cytochrome ◽  
Mode Of Reproduction ◽  
The Third ◽  
Mode Of Life ◽  
Mitochondrial Cytochrome Oxidase

AbstractSpider mites, Tetranychidae, represent one of the most cosmopolitan and economically important groups of terrestrial arthropods; however, many aspects of their evolutionary relationships remain uncertain. We sequenced part of the mitochondrial cytochrome oxidase subunit I (COI) gene in 20 species of phytophagous mites belonging to nine genera and two families (Tetranychidae and Tenuipalpidae), including several agricultural pests. As eported in insects, the sequences were extremely rich in A + T (75% on average), especially in the third codon position (95%). However, one of the genera we studied had a significantly lower A + T content (69% on average, 78% in the third codon position), showing that base composition can change substantially over short periods of time. Most interspecific differences were transversions and their number increased steadily with the number of non-synonymous differences, while the number of transitions remained constant. The phylogeny based on COI sequences was inferred using the maximum likelihood method. The results are compatible as a whole with the traditional classification based on morphological characters, but call for some minor taxonomic revisions. Some morphological characters and life history traits (mode of reproduction, adaptation to the host plant) were also analysed within this phylogenetic framework. At the family level, one can see a trend towards thelytoky becoming rarer compared to the general mode of reproduction of the group, arrhenotoky. There is also an evolutionary tendency towards a more complex mode of life, with the production of silk webs and correlated changes of the locomotion apparatus. However, in the Tetranychidae there seems to have been convergent evolution of these morphological characters together with independent development of a common adaptation to this mode of life in different genera.

Mutational divergence of life-history traits in an obligate parthenogen

Genome ◽  
1994 ◽  
Vol 37 (1) ◽  
pp. 33-35 ◽  
Author(s):  
C. Anna Toline ◽  
Michael Lynch
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Sole Source ◽  
Morphological Characters ◽  
The Other ◽  
Life History Trait ◽  
Adaptive Changes ◽  
Significant Divergence ◽  
Polygenic Variation

Three lines of obligately parthenogenetic Daphnia were allowed to diverge for a 4-year period (approximately 150 generations) with mutation as the sole source of variability. Life-history traits and morphological characters were then surveyed for between-line differences. Significant divergence was found with respect to both number and size of offspring, with no difference in total offspring biomass. No significant differences were found in any of the other characters. These results confirm the hypothesis that purely asexual lines can accumulate enough polygenic variation via mutation to support potentially adaptive changes on a microevolutionary time scale.Key words: Daphnia, life-history trait, mutational divergence, microevolution.

Carbon isotope composition of tree leaves from Guanacaste, Costa Rica: comparison across tropical forests and tree life history

2002 ◽  
Vol 18 (1) ◽  
pp. 151-159 ◽  
Author(s):  
A. JOSHUA LEFFLER ◽  
BRIAN J. ENQUIST
Keyword(s):  
Life History ◽  
Functional Diversity ◽  
Life History Traits ◽  
Isotope Composition ◽  
Tropical Climate ◽  
Tropical Plants ◽  
The Past ◽  
Physiological Diversity ◽  
Tight Association ◽  
Made In

Despite the progress made in understanding the ecophysiology of tropical plants during the past two decades (Lüttge 1997, Mulkey et al. 1996), questions regarding relationships between the environment and physiological diversity remain. It is now recognized that tropical climate can be quite variable (see Coen 1983) which could lead to significant functional diversity (increased variation in life history traits) among species due to the tight association between gas exchange physiology and the environment (see Enquist & Leffler 2001, Guehl et al. 1998, Huc et al. 1994, Martinelli et al. 1998, Sobrado 1993). It remains unclear, however, how the subtleties of variation in tropical climate and tree life history traits are related to the functional diversity of tropical communities (Borchert 1994, 1998).

scholarly journals Microbiota Influences Fitness and Timing of Reproduction in the Fruit Fly Drosophila melanogaster

2021 ◽  
Author(s):  
Melinda K. Matthews ◽  
Jaanna Malcolm ◽  
John M. Chaston
Keyword(s):  
Drosophila Melanogaster ◽  
Life History ◽  
Microbial Communities ◽  
Life History Traits ◽  
Fruit Fly ◽  
Clear Definition ◽  
Animal Life ◽  
Timing Of Reproduction ◽  
The Past ◽  
Definition Of

The ability of associated microorganisms (“microbiota”) to influence animal life history traits has been recognized and investigated, especially in the past 2 decades. For many microbial communities, there is not always a clear definition of whether the microbiota or its members are beneficial, pathogenic, or relatively neutral to their hosts’ fitness.

Introduction

2019 ◽  
pp. 1-16
Keyword(s):  
French Revolution ◽  
Transitional Justice ◽  
Recent Literature ◽  
The Past ◽  
Revolutionary Violence ◽  
The Future ◽  
The Subject ◽  
The French Revolution

The introductory chapter opens up the question of how to approach the aftermath of the Terror. Most of revolutionary historiography is focused on the origins of the event, not on its aftermath. This chapter argues that there is much to learn about the French Revolution and its relevance to our own times by studying the aftermath of the Terror. In articulating the book’s approach to the subject, the chapter draws on the recent literature on transitional justice and trauma, as well as on the much earlier ideas of Edgar Quinet. Approaching the aftermath of the Terror invites us to consider how those who had experienced revolutionary violence faced the past in the context of a movement oriented toward the future.

scholarly journals Description and comparison of the pupae of a further two Culicoides (Avaritia) species from the dung of large herbivores in South Africa (Diptera: Ceratopogonidae)

2009 ◽  
Vol 76 (3) ◽  
Author(s):  
Hilda Nevill ◽  
E.M. Nevill ◽  
G.J. Venter
Keyword(s):  
Distinct Species ◽  
Morphological Characters ◽  
Culicoides Species ◽  
Large Herbivores ◽  
Closely Related Species ◽  
The Past ◽  
Taxonomic Description ◽  
Unpublished Thesis ◽  
The Subject ◽  
Present Description

In 2007 Nevill, Venter, Meiswinkel & Nevill demonstrated that the pupae of five Culicoides species belonging to the Imicola complex of the subgenus Avaritia could readily be differentiated from one another using various morphological characters. Three of the described species, Culicoides bolitinos Meiswinkel 1989; Culicoides loxodontis Meiswinkel 1992 and Culicoides sp. # 107 (= C. kwagga, Meiswinkel, unpublished thesis 1995), were reared from the dung of large herbivores, which included buffaloes, elephants, white and black rhinoceroses and zebras. However, during that study a further two Avaritia species, neither of which belonged to the Imicola complex, were reared from dung and these are the subject of the present study. For the past 20 years the adults of these two new closely related species have been known as Culicoides sp. # 54 pale form (p.f.) Meiswinkel and Culicoides sp. # 54 dark form (d.f.) Meiswinkel. The taxonomic description and formal naming of the adults of these two species has yet to be done. The present description and comparison of their pupae show that they are two clearly distinct species; that there is no group of morphological characters that can be used to differentiate these two species from the previously described five species of the Imicola complex; and finally that there was no difference between the pupae of C. sp. # 54 d.f. nor C. sp. # 54 p.f. reared from the dung of different host animals.

Three sibling species of didemnid ascidians from northern Norway: Didemnum albidum (Verrill, 1871), Didemnum polare (Hartmeyer, 1903), and Didemnum romssae sp.nov.

1996 ◽  
Vol 74 (2) ◽  
pp. 357-379 ◽  
Author(s):  
Jessica A. Marks
Keyword(s):  
Life History ◽  
Sibling Species ◽  
Distinct Species ◽  
Morphological Characters ◽  
Reticulate Evolution ◽  
Life History Variation ◽  
Larval Size ◽  
Colonial Ascidian ◽  
Northern Norway ◽  
Didemnid Ascidians

Recent advances in taxonomy have disclosed the prevalence of cryptic sibling species in marine systems. In didemnid ascidians, morphological variation between species is often slight, and many species may have been overlooked. Species boundaries within this group are often equivocal, and patterns among taxa are reminiscent of those formed by reticulate evolution in plants. Specimens of the sessile colonial ascidian Didemnum albidum (Verrill, 1871) were examined for life-history and morphological characters and found to constitute at least three sympatric sibling species. One of these, Didemnum romssae, is described here as a new species. Colonies were collected from hard-bottom assemblages in Troms and Finnmark counties in northern Norway. Zooid morphology in D. romssae is similar to that of D. albidum, but varies within each species, even for traits usually considered specific. Didemnum romssae is proposed as a distinct species on the basis of consistent differences in (i) the shape and size of calcium carbonate spicules within the common test; (ii) larval size and the number of lateral ampullae; (iii) timing of reproduction; and (iv) the absence of a seasonal nonfeeding, overwintering stage, which occurs in D. albidum. Examination of specimens from museum collections considered synonymous with D. albidum confirmed the presence of a third species, Didemnum polare (Hartmeyer, 1903), which differed from the other two species in zooid and larval morphology as well as spicule shape. Complexes of sibling species such as these provide a tractable system for studying the consequences of life-history variation among closely related taxa.

Evolution of earlyHomo: An integrated biological perspective

Science ◽  
2014 ◽  
Vol 345 (6192) ◽  
pp. 1236828 ◽  
Author(s):  
Susan C. Antón ◽  
Richard Potts ◽  
Leslie C. Aiello
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Homo Sapiens ◽  
Selective Advantage ◽  
Environmental Data ◽  
Evolutionary Time ◽  
The Past ◽  
Biological Perspective ◽  
Dietary Flexibility ◽  
Hind Limbs

Integration of evidence over the past decade has revised understandings about the major adaptations underlying the origin and early evolution of the genusHomo. Many features associated withHomo sapiens, including our large linear bodies, elongated hind limbs, large energy-expensive brains, reduced sexual dimorphism, increased carnivory, and unique life history traits, were once thought to have evolved near the origin of the genus in response to heightened aridity and open habitats in Africa. However, recent analyses of fossil, archaeological, and environmental data indicate that such traits did not arise as a single package. Instead, some arose substantially earlier and some later than previously thought. From ~2.5 to 1.5 million years ago, three lineages of earlyHomoevolved in a context of habitat instability and fragmentation on seasonal, intergenerational, and evolutionary time scales. These contexts gave a selective advantage to traits, such as dietary flexibility and larger body size, that facilitated survival in shifting environments.

Materials for Electron Beam Information Storage

1969 ◽  
Vol 27 ◽  
pp. 152-153 ◽  
Author(s):  
D. E. Speliotis
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Recent Literature ◽  
Electron Beams ◽  
Information Storage ◽  
The Subject ◽  
The Magnetic Field

The interaction of electron beams with a large variety of materials for information storage has been the subject of numerous proposals and studies in the recent literature. The materials range from photographic to thermoplastic and magnetic, and the interactions with the electron beam for writing and reading the information utilize the energy, or the current, or even the magnetic field associated with the electron beam.

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