Oedipal mating as a factor in sex allocation in haplodiploids

1993 ◽  
Vol 341 (1296) ◽  
pp. 195-202 ◽  

Most theoretical work on brood sex ratio bias is based on life histories involving potential sibmating, where inseminated females colonize a habitat producing progeny that mate randomly among themselves. However, another type of life history can favour female biased broods; it involves motherson matings and is uniquely accessible to haplodiploids. Colonization is accomplished by immature stages (mating is postdispersal) and female bias is favoured at low colonization densities by the fact that, unlike isolated males, isolated females are not lost to the gene pool because they can mate with their parthenogenetically produced sons. We present a mathematical model of the life history including parameters describing colonization density, degree of aggregation, the penalty incurred when a female must wait to mate with her parthenogenetically produced son, and inbreeding. Low colonization density favours female bias as does increased aggregation; a high penalty associated with waiting for maturation of a son with which to mate means that some proportion of males among progeny will be favoured even at very low colonization densities. Life histories that fit the model are known in nematodes and mites.

2020 ◽  
Author(s):  
Sha Jiang ◽  
Harman Jaggi ◽  
Wenyun Zuo ◽  
Madan K. Oli ◽  
Jean-Michel Gaillard ◽  
...  

AbstractTransient dynamics are crucial for understanding ecological and life-history dynamics. In this study, we analyze damping time, the time taken by a population to converge to a stable (st)age structure following a perturbation, for over 600 species of animals and plants. We expected damping time to be associated with both generation time Tc and demographic dispersion σ based on previous theoretical work. Surprisingly, we find that damping time (calculated from the population projection matrix) is approximately proportional to Tc across taxa on the log-log scale, regardless of σ. The result suggests that species at the slow end of fast-slow continuum (characterized with long generation time, late maturity, low fecundity) are more vulnerable to external disturbances as they take more time to recover compared to species with fast life-histories. The finding on damping time led us to next examine the relationship between generation time and demographic dispersion. Our result reveals that the two life-history variables are positively correlated on a log-log scale across taxa, implying long generation time promotes demographic dispersion in reproductive events. Finally, we discuss our results in the context of metabolic theory and contribute to existing allometric scaling relationships.


1964 ◽  
Vol 96 (1-2) ◽  
pp. 159-159
Author(s):  
H. J. Teskey

Relatively little is known of the life history, ecology and behaviour of most species of Tabanidae. Knowledge of their immature stages is particularly deficient. The larvae of only 46, or about ⅛, of the North American species have been described and many of these descriptions are inadequate. The present research was initiated in 1960 to describe and classify tabanid larvae and to contribute information on larval habitats and life histories.


1990 ◽  
Vol 68 (6) ◽  
pp. 1227-1232 ◽  
Author(s):  
Heather C. Proctor ◽  
Gordon Pritchard

The life history of a member of the widely distributed Unionicola crassipes complex (Acari: Unionicolidae) in a foothills pond in Alberta, Canada, differs from those previously described for this taxon. Two years are required for a female to develop from an egg to an ovipositing adult. Fertilized females overwinter and oviposit in the sponge Eunapius fragilis in early May. Larvae emerge in late May to early June and parasitize chironomids of the genus Tanytarsus. Engorged larvae drop from their insect hosts and return to sponges for the protonymph resting stage. Active, predaceous deutonymphs develop from protonymphs in early summer. Deutonymphs overwinter and enter the tritonymph resting stage, also in sponges, in early May. Summer adults emerge from the tritonymph stage in late May to early June. Males emerge first, but there is an overall female bias to the sex ratio of emerging adults. Growth of sclerotized and unsclerotized parts occurs in adults over the summer, during which time females appear to suffer greater mortality than males, because the sex ratio is 1:1 in September. It is primarily mated females that overwinter for a second time. A population decline in the summer of 1987 was correlated with degeneration of sponges; variation in the life histories of sponge-associated water mites is discussed in light of this correlation.


2002 ◽  
Vol 357 (1419) ◽  
pp. 373-380 ◽  
Author(s):  
J. Komdeur ◽  
I. Pen

We review some recent theoretical and empirical developments in the study of sex allocation in birds. The advent of reliable molecular sexing techniques has led to a sharp increase in the number of studies that report biased offspring sex ratios in birds. However, compelling evidence for adaptive sex allocation in birds is still very scant. We argue that there are two reasons for this: (i) standard sex allocation models, very helpful in understanding sex allocation of invertebrates, do not sufficiently take the complexities of bird life histories and physiology into account. Recent theoretical work might bring us a step closer to more realistic models; (ii) experimental field and laboratory studies on sex allocation in birds are scarce. Recent experimental work both in the laboratory and in the field shows that this is a promising approach.


Author(s):  
Maren N. Vitousek ◽  
Laura A. Schoenle

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.


2019 ◽  
Vol 144 (4) ◽  
pp. 389-411 ◽  
Author(s):  
Ramsés Djidjou‐Demasse ◽  
Gbenga J. Abiodun ◽  
Abiodun M. Adeola ◽  
Joel O. Botai

2021 ◽  
pp. 025576142199115
Author(s):  
Tim Palmer ◽  
David Baker

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.


2012 ◽  
Vol 22 (1) ◽  
pp. 79-115 ◽  
Author(s):  
Martin Scanlan

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.


Parasitology ◽  
1959 ◽  
Vol 49 (3-4) ◽  
pp. 374-386 ◽  
Author(s):  
R. J. Thomas

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.


1932 ◽  
Vol 57 (1) ◽  
pp. 93-142 ◽  
Author(s):  
Elsie J. Cadman

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.


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