scholarly journals The various ways that anadromous salmonids use lake habitats to complete their life history

2021 ◽  
Vol 78 (1) ◽  
pp. 90-100
Author(s):  
Robert J. Lennox ◽  
Ulrich Pulg ◽  
Brendan Malley ◽  
Sven-Erik Gabrielsen ◽  
Erlend M. Hanssen ◽  
...  
Keyword(s):  
Life History ◽  
High Mortality ◽  
Human Activities ◽  
Life Histories ◽  
Behavioural Thermoregulation ◽  
Knowledge Gaps ◽  
Iteroparous Species ◽  
Oxygen Ice ◽  
Lake Habitats ◽  
Genetics Of Populations

Despite the preponderance of exorheic lakes in rivers home to anadromous salmonids, little research has focused on how salmon, trout, and char use lakes as part of their anadromous life histories. The literature on this subject has so far revealed that some parr move into lakes to feed and grow before smoltification but that smolts moving through lakes tend to have high mortality in disproportion to what is observed in other habitats they migrate in or through. Adults have been observed using lakes for behavioural thermoregulation prior to spawning, and kelts of iteroparous species often exploit lakes to overwinter before returning to sea to recondition. We summarized knowledge on lakes as salmonid habitat and identified knowledge gaps about the use of lakes by anadromous salmonids related to whether lakes are barriers that structure genetics of populations, whether mortality in lakes is compensatory or additive, and whether systems with lakes have higher rates of repeat spawning among iteroparous salmonids. Human activities that alter lakes require further study to understand how changes in temperature, oxygen, ice, or circulation affect navigation and fate.

scholarly journals Generation time, life history and the substitution rate of neutral mutations

2014 ◽  
Vol 10 (11) ◽  
pp. 20140801 ◽  
Author(s):  
Jussi Lehtonen ◽  
Robert Lanfear
Keyword(s):  
Life History ◽  
Generation Time ◽  
Life Histories ◽  
Life History Traits ◽  
Theoretical Understanding ◽  
Substitution Rates ◽  
Demographic Theory ◽  
Full Life ◽  
Iteroparous Species ◽  
Neutral Mutations

Our understanding of molecular evolution is hampered by a lack of quantitative predictions about how life-history (LH) traits should correlate with substitution rates. Comparative studies have shown that neutral substitution rates vary substantially between species, and evidence shows that much of this diversity is associated with variation in LH traits. However, while these studies often agree, some unexplained and contradictory results have emerged. Explaining these results is difficult without a clear theoretical understanding of the problem. In this study, we derive predictions for the relationships between LH traits and substitution rates in iteroparous species by using demographic theory to relate commonly measured life-history traits to genetic generation time, and by implication to neutral substitution rates. This provides some surprisingly simple explanations for otherwise confusing patterns, such as the association between fecundity and substitution rates. The same framework can be applied to more complex life histories if full life-tables are available.

Hormones and Behavior

2019 ◽  
pp. 11-26
Author(s):  
Maren N. Vitousek ◽  
Laura A. Schoenle
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Traits ◽  
Developmental Plasticity ◽  
Endocrine System ◽  
Phenotypic Traits ◽  
Social Environments ◽  
Trade Offs ◽  
And Behavior

Hormones mediate the expression of life history traits—phenotypic traits that contribute to lifetime fitness (i.e., reproductive timing, growth rate, number and size of offspring). The endocrine system shapes phenotype by organizing tissues during developmental periods and by activating changes in behavior, physiology, and morphology in response to varying physical and social environments. Because hormones can simultaneously regulate many traits (hormonal pleiotropy), they are important mediators of life history trade-offs among growth, reproduction, and survival. This chapter reviews the role of hormones in shaping life histories with an emphasis on developmental plasticity and reversible flexibility in endocrine and life history traits. It also discusses the advantages of studying hormone–behavior interactions from an evolutionary perspective. Recent research in evolutionary endocrinology has provided insight into the heritability of endocrine traits, how selection on hormone systems may influence the evolution of life histories, and the role of hormonal pleiotropy in driving or constraining evolution.

scholarly journals Classical soloists’ life histories and the music conservatoire

2021 ◽  
pp. 025576142199115
Author(s):  
Tim Palmer ◽  
David Baker
Keyword(s):  
Higher Education ◽  
Life History ◽  
Life Histories ◽  
Qualitative Data ◽  
Classical Music ◽  
Loss Of Autonomy ◽  
Cultural Interest ◽  
Concert Pianist ◽  
Analytic Induction ◽  
Musical Excellence

This article explores the life histories of virtuoso classical music soloists with particular reference to conservatoire provision. Detailed life-history interviews were conducted with six virtuosi between May 2018 and January 2019. These participants were three singers, two cellists and a concert pianist. Resultant qualitative data were stored in an NVivo software database and understood through a process of analytic induction. Key findings spotlight the significance of Higher Education, a connection between broad creative and cultural interest and musical excellence, and a significant role for conservatoires in diversifying their training and easing transition into the career. The soloists also warned of dangers relating to controlling teachers, loss of autonomy and a need to convey their career realities to students.

Inadvertent Exemplars: Life History Portraits of Two Socially Just Principals

2012 ◽  
Vol 22 (1) ◽  
pp. 79-115 ◽  
Author(s):  
Martin Scanlan
Keyword(s):  
Social Justice ◽  
Life History ◽  
Elementary Schools ◽  
Middle Class ◽  
Life Histories ◽  
Public Elementary Schools ◽  
White Middle Class ◽  
English Speaking ◽  
Native English Speaking

This study creates life history portraits of two White middle-class native-English-speaking principals demonstrating commitments to social justice in their work in public elementary schools serving disproportionately high populations of students who are marginalized by poverty, race, and linguistic heritage. Through self-reported life histories of these principals, I create portraits that illustrate how these practitioners draw motivation, commitment, and sustenance in varied, complicated, and at times contradictory ways.

A comparative study of the life histories of Nematodirus battus and N. filicollis, nematode parasites of sheep

Parasitology ◽  
1959 ◽  
Vol 49 (3-4) ◽  
pp. 374-386 ◽  
Author(s):  
R. J. Thomas
Keyword(s):  
Life History ◽  
Intestinal Mucosa ◽  
Related Species ◽  
Life Histories ◽  
Basic Pattern ◽  
Culture Methods ◽  
Closely Related Species ◽  
Nematode Parasites ◽  
History Of ◽  
Comparative Description

1. The life history of N. battus is described, and a comparative description of the life history of N. filicollis is given.2. The life histories of these two species are compared with those of N. spathiger and N. helvetianus, two closely related species, and are shown to follow the same basic pattern, with minor variations in timing which appear to be specific in nature, and not related to differences in culture methods or host species.3. The pathogenesis of Nematodirus species is discussed and related to the migration of larvae into the intestinal mucosa during development.

Meristem allocation and life-history evolution in herbaceous plants

2006 ◽  
Vol 84 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Stephen P. Bonser ◽  
Lonnie W. Aarssen
Keyword(s):  
Life History ◽  
Apical Dominance ◽  
Reproductive Effort ◽  
Life History Evolution ◽  
Meristem Development ◽  
Vegetative Traits ◽  
History Evolution ◽  
Meristem Allocation ◽  
Branching Intensity ◽  
Iteroparous Species

Generalisations of life histories in plants are often framed in terms of allocation to reproduction. For example, relative allocation to reproduction is commonly found to be higher in semelparous than in iteroparous plant species. However, the association between vegetative traits and life history has been largely unexplored. In higher plants, reproductive and vegetative function can be measured in terms of meristem allocation. Under this approach, two vegetative traits (apical dominance (the suppression of axillary meristem development) and branching intensity (the commitment of axillary meristems to branches)) can be measured as well as one reproductive trait (reproductive effort). We used phylogenetically independent contrasts to compare reproductive and vegetative function in annual semelparous and perennial iteroparous species. Twenty congeneric species pairs (each species pair represented by one semelparous and one iteroparous species) across nine families were selected based on availability of herbarium specimens. Semelparous life-history evolution was associated with higher reproductive effort. Conversely, iteroparous life-history evolution was associated with higher apical dominance. Branching intensity was not associated with life history. An evolutionary association between life history and apical dominance but not branching intensity suggests a complex relationship between allocation to vegetative traits and the evolution of plant strategies across environments.

III.—The Life-history and Cytology of Didymium nigripes Fr.

1932 ◽  
Vol 57 (1) ◽  
pp. 93-142 ◽  
Author(s):  
Elsie J. Cadman
Keyword(s):  
Life History ◽  
Life Histories ◽  
Important Research ◽  
Great Work ◽  
Animal Kingdom ◽  
History Of ◽  
Natural Groups

Since 1860, in which year De Bary published his great work Die Mycetozoen, the investigation of the life-history of members of the Mycetozoa has aroused a considerable amount of interest, and a great deal of important research has been carried out in this connection. The group of organisms is particularly interesting, because it lies on the borderline between plant and animal kingdoms, and it is very possible that a detailed investigation of several species of the Mycetozoa might be of considerable assistance in elucidating certain obscure points in the life-histories of higher members of both the great natural groups. The term “Mycetozoa,” which we owe to De Bary, will be used throughout in preference to the older term “Myxogastres” invented by Fries (32, p. 2), and that of “Myxomycetes” first employed by Link (32, p. 2). “Mycetozoon,” or “fungus-like animal,” is a very appropriate description of a member of the group, since during part of its life-history it exhibits distinctly animal-like characters, and the individuals move rapidly by means of flagella, whilst later, during the development of the sporangium, a plant-like form is assumed. The combination of plant and animal characters has given rise to much discussion as to the position of the Mycetozoa in plant or animal kingdom, and the group has been claimed by both zoologists and botanists.

A Primer of Life Histories

2021 ◽  
Author(s):  
Jeffrey A. Hutchings
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Theory ◽  
Life History Traits ◽  
Reproductive Effort ◽  
Effective Means ◽  
Academic Experience ◽  
Sustainable Exploitation ◽  
Evolution Of Life ◽  
Opportune Time

Life histories describe how genotypes schedule their reproductive effort throughout life in response to factors that affect their survival and fecundity. Life histories are solutions that selection has produced to solve the problem of how to persist in a given environment. These solutions differ tremendously within and among species. Some organisms mature within months of attaining life, others within decades; some produce few, large offspring as opposed to numerous, small offspring; some reproduce many times throughout their lives while others die after reproducing just once. The exponential pace of life-history research provides an opportune time to engage and re-engage new generations of students and researchers on the fundamentals and applications of life-history theory. Chapters 1 through 4 describe the fundamentals of life-history theory. Chapters 5 through 8 focus on the evolution of life-history traits. Chapters 9 and 10 summarize how life-history theory and prediction has been applied within the contexts of conservation and sustainable exploitation. This primer offers an effective means of rendering the topic accessible to readers from a broad range of academic experience and research expertise.

scholarly journals The application of life history information to the conservation management of Chrysoritis butterflies (Lepidoptera: Lycaenidae) in South Africa

Koedoe ◽  
2004 ◽  
Vol 47 (1) ◽  
Author(s):  
R.F. Terblanche ◽  
H. Van Hamburg
Keyword(s):  
South Africa ◽  
Life History ◽  
Life Histories ◽  
Host Plants ◽  
Conservation Management ◽  
Aesthetic Value ◽  
Wing Patterns ◽  
In The Wild ◽  
History Of ◽  
Voucher Specimens

Due to their intricate life histories and the unique wing patterns and colouring the butterflies of the genus Chrysoritis are of significant conservation and aesthetic value. Thisoverview probes into practical examples of butterfly life history research applicable to environmental management of this relatively well-known invertebrate group in South Africa. Despite the pioneer work on life histories of Chrysoritis in the past, more should be done to understand the life history of the butterflies in the wild, especially their natural host plants and the behaviour of adults and larvae. A system of voucher specimens of host plants should be introduced in South Africa. Although various host plant species in nature are used by the members of Chrysoritis, including the Chrysoritis chrysaor group, the choice of these in nature by each species is significant for conservation management and in the case of Chrysoritis aureus perhaps even as a specific characteristic.A revision of the ant genus Crematogaster will benefit the conservation management of Chrysoritis species since some of these ant species may consist of a number of specieswith much more restricted distributions than previously thought. Rigorous quantified tudies of population dynamics of Chrysoritis butterflies are absent and the introductionof such studies will benefit conservation management of these localised butterflies extensively.

Socialist Modernisation in Mongolia as Narrated after Socialism

Inner Asia ◽  
2010 ◽  
Vol 12 (1) ◽  
pp. 5-23 ◽  
Author(s):  
Yuki Konagaya
Keyword(s):  
Life History ◽  
Oral History ◽  
Life Histories ◽  
Oral Histories ◽  
View Point ◽  
The Past ◽  
Ex Post ◽  
History Narratives

AbstractIn this article I introduce our collection of oral histories composed of life histories recorded between 2001 and 2006. First, I discuss some devices implemented in the process of collecting life histories, which was to make oral histories 'polyphonic'. I then suggest that oral history always has a 'dual' tense, in that people talk about 'the past' from the view point of 'the present'. This is illustrated by six cases of statesmen narrating their views about socialist modernisation. Finally, using one of the cases, I demonstrate the co-existence of non-official or private opinions along with official opinions about the socialist period in life-history narratives in the post-socialist period. I call this 'ex-post value'.

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