The Evolution of Life History Parameters in Teleosts

1984 ◽  
Vol 41 (6) ◽  
pp. 989-1000 ◽  
Author(s):  
Derek A. Roff
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Life History Theory ◽  
Larval Survival ◽  
Reasonable Assumption ◽  
Natural Mortality ◽  
Age At First Reproduction ◽  
Life History Parameters ◽  
First Case ◽  
First Reproduction

Empirical studies have shown that in teleosts there is a significant correlation between the life history parameters, age at first reproduction, natural mortality, and growth rate. In this paper 1 hypothesize that these correlations are the result of evolutionary adjustments due to the trade-off between reproduction, growth, and survival. A simple and reasonable assumption is that the costs of reproduction are sufficient to cause the ltmt function to decrease. A simple expression relating the age at first reproduction is derived from this assumption. This formula accounts for a statistically significant portion (60.6%) of the variation in age at first reproduction in 30 stocks of fish. To extend the model to predict the distribution of life history parameters across all teleosts, an explicit cost function is incorporated. The model is analyzed with respect to two fitness measures, the expected lifetime fecundity and malthusian parameter, r. In the first case it is shown that the optimal age at maturity, T, depends only on the natural mortality rate (M) and the growth rate (k). In the second case, T is a function of k and the logarithm of a parameter, In C; the latter is a product of egg and larval survival, maximum body length (Lx), and the proportionality coefficient of the fecundity/length function. Difficulties of measuring egg and larval survival make the testing of the latter case difficult for particular species. However, this method provides a simple formula for the computation of r; this is shown generally to be approximately zero, thereby adding strength to the assumptions of the first analysis. The distribution patterns of T on k and M on k are predicted and compared with the observed pattern. In general, the predictions are validated: however, certain combinations of k and ln C are shown to occur very infrequently. The prediction of such "empty" regions of the parameter space remains a challenge for future development of life history theory.

scholarly journals Life-history theory, chronic childhood illness and the timing of first reproduction in a British birth cohort

2012 ◽  
Vol 279 (1740) ◽  
pp. 2998-3002 ◽  
Author(s):  
David Waynforth
Keyword(s):  
Life History ◽  
Chronic Disease ◽  
Life Expectancy ◽  
Life History Theory ◽  
Pubertal Development ◽  
Experimental Studies ◽  
Past Research ◽  
Theoretical Models ◽  
Age At First Reproduction ◽  
First Reproduction

Life-history theoretical models show that a typical evolutionarily optimal response of a juvenile organism to high mortality risk is to reach reproductive maturity earlier. Experimental studies in a range of species suggest the existence of adaptive flexibility in reproductive scheduling to maximize fitness just as life-history theory predicts. In humans, supportive evidence has come from studies comparing neighbourhoods with different mortality rates, historical and cross-cultural data. Here, the prediction is tested in a novel way in a large ( n = 9099), longitudinal sample using data comparing age at first reproduction in individuals with and without life-expectancy-reducing chronic disease diagnosed during childhood. Diseases selected for inclusion as chronic illnesses were those unlikely to be significantly affected by shifting allocation of effort away from reproduction towards survival; those which have comparatively large effects on mortality and life expectancy; and those which are not profoundly disabling. The results confirmed the prediction that chronic disease would associate with early age at first reproduction: individuals growing up with a serious chronic disease were 1.6 times more likely to have had a first child by age 30. Analysis of control variables also confirmed past research findings on links between being raised father-absent and early pubertal development and reproduction.

scholarly journals Palaeohistology reveals a slow pace of life for the dwarfed Sicilian elephant

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meike Köhler ◽  
Victoria Herridge ◽  
Carmen Nacarino-Meneses ◽  
Josep Fortuny ◽  
Blanca Moncunill-Solé ◽  
...  
Keyword(s):  
Life History ◽  
Body Mass ◽  
Growth Period ◽  
Extended Period ◽  
Island Rule ◽  
Rule Based ◽  
Age At First Reproduction ◽  
Slow Pace ◽  
First Reproduction ◽  
Adaptive Shifts

AbstractThe 1-m-tall dwarf elephant Palaeoloxodon falconeri from the Pleistocene of Sicily (Italy) is an extreme example of insular dwarfism and epitomizes the Island Rule. Based on scaling of life-history (LH) traits with body mass, P. falconeri is widely considered to be ‘r-selected’ by truncation of the growth period, associated with an early onset of reproduction and an abbreviated lifespan. These conjectures are, however, at odds with predictions from LH models for adaptive shifts in body size on islands. To settle the LH strategy of P. falconeri, we used bone, molar, and tusk histology to infer growth rates, age at first reproduction, and longevity. Our results from all approaches are congruent and provide evidence that the insular dwarf elephant grew at very slow rates over an extended period; attained maturity at the age of 15 years; and had a minimum lifespan of 68 years. This surpasses not only the values predicted from body mass but even those of both its giant sister taxon (P. antiquus) and its large mainland cousin (L. africana). The suite of LH traits of P. falconeri is consistent with the LH data hitherto inferred for other dwarfed insular mammals. P. falconeri, thus, not only epitomizes the Island Rule but it can also be viewed as a paradigm of evolutionary change towards a slow LH that accompanies the process of dwarfing in insular mammals.

scholarly journals Trade-off between age of first reproduction and survival in a female primate

2009 ◽  
Vol 5 (3) ◽  
pp. 339-342 ◽  
Author(s):  
Gregory E. Blomquist
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Rhesus Macaques ◽  
Human Study ◽  
Genetic Correlations ◽  
Adult Survival ◽  
Trade Off ◽  
Trade Offs ◽  
Female Life History ◽  
First Reproduction

Trade-offs are central to life-history theory but difficult to document. Patterns of phenotypic and genetic correlations in rhesus macaques, Macaca mulatta —a long-lived, slow-reproducing primate—are used to test for a trade-off between female age of first reproduction and adult survival. A strong positive genetic correlation indicates that female macaques suffer reduced adult survival when they mature relatively early and implies primate senescence can be explained, in part, by antagonistic pleiotropy. Contrasts with a similar human study implicate the extension of parental effects to later ages as a potential mechanism for circumventing female life-history trade-offs in human evolution.

Using r-K Selection Theory to Predict Natural Mortality

1980 ◽  
Vol 37 (12) ◽  
pp. 2266-2271 ◽  
Author(s):  
Donald R. Gunderson
Keyword(s):  
Body Weight ◽  
Life History ◽  
Growth Parameters ◽  
Stepwise Multiple Regression ◽  
Natural Mortality ◽  
Instantaneous Rate ◽  
Life History Parameters ◽  
Selection Theory ◽  
Weight Index ◽  
Body Weight Index

Theory on r-K selection is used as a basis for examining correlations between instantaneous rate of natural mortality (M), gonad-body weight index, age at maturity, longevity, and Bertalanffy growth parameters (k, L∞) for 10 species of marine fish. All correlations were consistent with r-K selection theory. The gonad-body weight index was found to be more highly correlated with M than any of the other life history parameters examined (r2 = 0.62), and stepwise multiple regression showed that additional variables added little to the predictive ability of the model. The gonad-body weight index appears to be quite useful in predicting M, and development of an analogous index on an energetics basis might enhance its utility in this regard.Key words: natural mortality, r-K selection, life history parameters

scholarly journals Preventing co-infection: a viral strategy with short-term benefits and long-term drawbacks

2021 ◽  
Author(s):  
Michael Hunter ◽  
Diana Fusco
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Negative Impact ◽  
Viral Evolution ◽  
Viral Fitness ◽  
Viral Population ◽  
Short Term ◽  
Life History Parameters ◽  
Wide Range

ABSTRACTViral co-infection occurs when multiple distinct viral particles infect the same host. This can impact viral evolution through intracellular interactions, complementation, reassortment and recombination. In nature many viral species are found to have a wide range of mechanisms to prevent co-infection, which raises the question of how viral evolution is impacted by this strategic choice. Here, we address this question in a model viral system, the ubiquitous bacteriophage and its host bacteria. Using a stochastic model of phage-host interactions in agent-based simulations, we first characterise the behaviour of neutral mutants and find that co-infection decreases the strength of genetic drift. We then quantify how variations in the phage life history parameters affect viral fitness. Importantly, we find that the growth rate (dis)advantage associated with variations in life history parameters can be dramatically different from the competitive (dis)advantage measured in direct-competition simulations. Additionally, we find that co-infection facilitates the fixation of beneficial mutations and the removal of deleterious ones, suggesting that selection is more efficient in co-infecting populations. We also observe, however, that in populations which allow co-infection, a mutant that prevents it displays a substantial competitive advantage over the rest of the population, and will eventually fix even if it displays a much lower growth rate in isolation. Our findings suggest that while preventing co-infection can have a negative impact on the long-term evolution of a viral population, in the short-term it is ultimately a winning strategy, possibly explaining the prevalence of phage capable of preventing co-infection in nature.

scholarly journals Effects of non-toxic filamentous cyanobacteria isolated from tri an reservoir on Daphnia

2020 ◽  
Vol 42 (3) ◽  
Author(s):  
Pham Thanh Luu ◽  
Tran Thi Hoang Yen ◽  
Tran Thanh Thai ◽  
Ngo Xuan Quang ◽  
Hoang Nghia Son
Keyword(s):  
High Performance Liquid Chromatography ◽  
Life History ◽  
Liquid Chromatography ◽  
Secondary Metabolites ◽  
High Performance ◽  
Toxic Effects ◽  
Filamentous Cyanobacteria ◽  
Age At First Reproduction ◽  
Bioactive Secondary Metabolites ◽  
First Reproduction

This study is aimed to examine whether the presence of non-toxic filamentous cyanobacteria can cause toxic effects on Daphnia magna. Six strains of Oscillatoria perornata were isolated from the Tri An Reservoir and cultured in our laboratory for investigation. The results revealed that all strains were negative with the mcyA moleculer marker. The high performance liquid chromatography (HPLC) results showed that toxin was not detected in their culture products, indicating that these strains corresponded to non-toxin producing strains. However, the results of chronic assay indicated that these non-toxin producing O. perornata conferred toxic effects on the tested animals. The age at first reproduction of D. magna was delayed and the survival of D. manga decreased in proportional with the increase of the density of cells of O. perornata exposed. Significant differences in the life history responses were observed for D. mangna exposed to O. perornata. These results suggested that bioactive secondary metabolites other than microcystins produced by the filamentous cyanobacteria O. perornata may contribute to the toxic effects on Daphnia. Besides cyanotoxins, other secondary metabolites must be taken into account when investigating the toxic effects of cyanobacteria.   

scholarly journals Preliminary Estimates of Age, Growth and Natural Mortality of Margate, Haemulon album, and Black Margate, Anisotremus surinamensis, from the Southeastern United States

Fishes ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 44
Author(s):  
Michael L. Burton ◽  
Jennifer C. Potts ◽  
Andrew D. Ostrowski
Keyword(s):  
United States ◽  
Life History ◽  
Atlantic Coast ◽  
Southeastern United States ◽  
Geographic Region ◽  
Fish Growth ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Life History Parameters ◽  
Growth Equations

Ages of margate, Haemulon album (n = 415) and black margate, Anisotremus surinamensis (n = 130) were determined using sectioned sagittal otoliths collected from the Southeastern United States Atlantic coast from 1979 to 2017. Opaque zones were annular, forming between January and June for both species, with peaks in occurrence of otoliths with opaque margins in April for margate and March for black margate. The observed ages for margate were 0–22 years, and the largest fish measured 807 mm TL (total length). Black margate ranged in age from 3 to 17 years, and the largest fish was 641 mm TL. Weight–length relationships were: margate, ln(W) = 2.88 ln(TL) − 10.44 (n = 1327, r2 = 0.97, MSE = 0.02), where W is total weight (grams, g); black margate, ln(W) = 3.02 ln(TL) − 11.10 (n = 451, r2 = 0.95, MSE = 0.01). Von Bertalanffy growth equations were Lt = 731 (1 − e−0.23(t+0.38)) for margate, and Lt = 544 (1 − e−0.13(t+2.61)) for black margate. After re-estimating black margate growth using a bias-correction procedure to account for the lack of younger fish, growth was described by the equation Lt = 523 (1 − e−0.18(t+0.0001)). Age-invariant estimates of natural mortality were M = 0.19 y−1 and M = 0.23 y−1 for margate and black margate, respectively, while age-varying estimates of M ranged from 2.93 −0.23 y−1 for fish aged 0–22 for margate and 7.20 − 0.19 y−1 for fish aged 0–18 for black margate. This study presents the first documentation of life-history parameters for margate from the Atlantic waters off the Southeastern United States, and the first published estimate of black margate life history parameters from any geographic region.

The Effects of Gunshot Residue Components (Pb, Ba, and Sb) on the Life History Traits of Lucilia sericata (Diptera: Calliphoridae)

2021 ◽  
Author(s):  
Meltem Kökdener ◽  
Ahmet Fazıl Yılmaz
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Larval Survival ◽  
Lucilia Sericata ◽  
Gunshot Residue ◽  
Larval Weight ◽  
Adult Weight ◽  
Life History Parameters ◽  
The Impact ◽  
Zoology Department

Abstract The present study aimed to investigate the impact of gunshot residue (GSR) components (Pb, Sb, and Ba) on the life history parameters of Lucilia sericata (Meigen, 1826) (Diptera: Calliphoridae). This experiment was carried out at the Zoology Department, the Ondokuz Mayıs University in 2020. About 50 larvae, respectively were exposed to the chicken liver with four different concentrations of GSR particles and life history parameters recorded. A two-way analysis of variance (Two way ANOVA) was used on the larval weight, and length, development time, percentage of pupal and larval survival. Pearson’s correlation coefficient was used to assess the association between life-history parameters and the concentration of GSR. The total development times decreased with increasing Sb, Ba, and Pb concentrations in the diets 1–3 d when compared to the control The results showed that Ba and Sb significantly decreased larval and pupal survival and GSR decreased the pupa and adult weight as compared to the control. We concluded that life-history parameters of L. sericata are sensitive to GSR residue and heavy metal changes in the environment. The presence of gunshot residue in the corpse should be kept in mind in a criminal investigation.

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