On the importance of life history and age structure in biological invasions

2011 ◽  
Vol 222 (3) ◽  
pp. 485-492 ◽  
Author(s):  
Johannes Järemo ◽  
Göran Bengtsson
Keyword(s):  
Life History ◽  
Biological Invasions ◽  
Age Structure

Life History Traits in a Population of Pelobates syriacus (Boettger, 1889) from Turkey

2020 ◽  
Vol 27 (4) ◽  
pp. 195-200
Author(s):  
Ufuk Bülbül ◽  
Halime Koç ◽  
Yasemin Odabaş ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
...  
Keyword(s):  
Life History ◽  
Age Structure ◽  
Life History Traits ◽  
Spadefoot Toad ◽  
Males And Females

Age structure of the eastern spadefoot toad, Pelobates syriacus from the Kızılırmak Delta (Turkey) were assessed using phalangeal skeletochronology. Snout-vent length (SVL) ranged from 42.05 to 86.63 mm in males and 34.03 to 53.27 mm in females. Age of adults ranged from 2 to 8 years in males and 3 to 5 years in females. For both sexes, SVL was significantly correlated with age. Males and females of the toads reached maturity at 2 years of age.

Evidence of long and discontinuous juvenile periods in Trillium catesbaei under contrasting levels of herbivory

Botany ◽  
2014 ◽  
Vol 92 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Christopher R. Webster ◽  
Michael A. Jenkins
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Age Structure ◽  
Morphological Characteristics ◽  
Population Viability ◽  
Plant Age ◽  
Life History Stage ◽  
Structure And Morphology ◽  
Single Leaf ◽  
Poor Indicator

We investigated the influence of chronic herbivory by white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) on the age structure and morphology of Trillium catesbaei Elliott. At sites with contrasting histories of deer abundance (Cades Cove, high; Whiteoak Sink, low), we measured morphological characteristics and determined minimum plant age for 60 plants (30 per site) in the single-leaf life-history stage. We chose this stage because its presence is considered an indication of successful reproduction by the previous generation, but its value could be inflated if plants regress or remain in this stage for extended periods. Our results suggest that T. catesbaei may spend upwards of a decade in this stage. Cades Cove single leaves were significantly older (p = 0.011) than those at Whiteoak Sink. Rhizome recession (decay of the oldest portion) was more common at Cades Cove, suggesting greater regression to this stage from three-leaf stages. Although minimum plant age was significantly associated with vegetative attributes (p < 0.002) at Whiteoak Sink, these attributes were decoupled at Cades Cove (p ≥ 0.642). Collectively, our results suggest that chronic herbivory may lead to a long and regressive residency period in the single-leaf stage. Consequently, in Trillium populations heavily impacted by deer, the number of single-leaf plants may be a poor indicator of reproductive success and population viability.

scholarly journals How life history can sway the fixation probability of mutants

2016 ◽  
Author(s):  
Xiang-Yi Li ◽  
Shun Kurokawa ◽  
Stefano Giaimo ◽  
Arne Traulsen
Keyword(s):  
Life History ◽  
Age Structure ◽  
Evolutionary Dynamics ◽  
Selective Advantage ◽  
Fixation Probability ◽  
Relative Importance ◽  
Demographic Structure ◽  
Frequency Dependent ◽  
Intermediate Fraction ◽  
Size And Structure

AbstractIn this work, we study the effects of demographic structure on evolutionary dynamics, when selection acts on reproduction, survival, or both. In contrast with the previously discovered pattern that the fixation probability of a neutral mutant decreases while population becomes younger, we show that a mutant with constant selective advantage may have a maximum or a minimum of the fixation probability in populations with an intermediate fraction of young individuals. This highlights the importance of life history and demographic structure in studying evolutionary dynamics. We also illustrate the fundamental differences between selection on reproduction and on survival when age structure is present. In addition, we evaluate the relative importance of size and structure of the population in determining the fixation probability of the mutant. Our work lays the foundation for studying also density and frequency dependent effects in populations when demographic structures cannot be neglected.

scholarly journals The importance of life history and population regulation for the evolution of social learning

2020 ◽  
Vol 375 (1803) ◽  
pp. 20190492 ◽  
Author(s):  
Dominik Deffner ◽  
Richard McElreath
Keyword(s):  
Life History ◽  
Social Learning ◽  
Age Structure ◽  
Life Histories ◽  
Population Regulation ◽  
Individual Learning ◽  
Vital Rates ◽  
Strategic Learning ◽  
Cognition And Culture ◽  
Exemplary Model

Social learning and life history interact in human adaptation, but nearly all models of the evolution of social learning omit age structure and population regulation. Further progress is hindered by a poor appreciation of how life history affects selection on learning. We discuss why life history and age structure are important for social learning and present an exemplary model of the evolution of social learning in which demographic properties of the population arise endogenously from assumptions about per capita vital rates and different forms of population regulation. We find that, counterintuitively, a stronger reliance on social learning is favoured in organisms characterized by ‘fast’ life histories with high mortality and fertility rates compared to ‘slower’ life histories typical of primates. Long lifespans make early investment in learning more profitable and increase the probability that the environment switches within generations. Both effects favour more individual learning. Additionally, under fertility regulation (as opposed to mortality regulation), more juveniles are born shortly after switches in the environment when many adults are not adapted, creating selection for more individual learning. To explain the empirical association between social learning and long life spans and to appreciate the implications for human evolution, we need further modelling frameworks allowing strategic learning and cumulative culture. This article is part of the theme issue ‘Life history and learning: how childhood, caregiving and old age shape cognition and culture in humans and other animals’.

Population age structure and growth in four syntopic amphibian species inhabiting a large river floodplain

2003 ◽  
Vol 81 (6) ◽  
pp. 1096-1106 ◽  
Author(s):  
Dan Cogalniceanu ◽  
Claude Miaud
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Age Structure ◽  
Environmental Conditions ◽  
Age Distribution ◽  
Large River ◽  
Danube River ◽  
Population Age Structure ◽  
River Floodplain ◽  
River Floodplains

River floodplains are disturbance-dominated landscapes where floods are major regulators of both aquatic and nearby terrestrial communities. Amphibians are common inhabitants of floodplains and their life cycle depends on both aquatic and terrestrial habitats. We focused on how different syntopic species of amphibians reacted to the environmental conditions of a large river floodplain. We examined life-history traits such as population age structure and growth in small- and large-bodied species of anurans and urodeles in the lower Danube River floodplain in Romania. Two newt species, Triturus vulgaris (small-bodied) and Triturus dobrogicus (large-bodied), and two anuran taxa, Bombina bombina (small-bodied) and the Rana esculenta complex (large-bodied), were included in the study. The ages of individuals estimated by skeletochronology varied from 3 to 5–6 years for T. vulgaris and from 2–3 to 4–5 years for T. dobrogicus. In the anurans, ages varied from 2 to 5 years in B. bombina and from 4 to 10 years in the R. esculenta complex. The numbers of breeding opportunities (i.e., the number of years the adults reproduce) are similar in both newt species (3), while growth rates and age at maturity differ between the large- and small-bodied species. In anurans, the number of breeding opportunities for the smallest species, B. bombina (4), is associated with a high growth rate and earlier maturation. In the larger R. esculenta complex, the higher number of breeding opportunities (7) is associated with a low growth rate and delayed maturation. The study of age distribution and associated parameters provides useful information on population life history. We discuss how age structure and growth of amphibian populations in large river floodplains can be used as indicators of environmental conditions.

Consequences of Habitat Fragmentation on Age Structure and Life History in a Tortoise Population1

Biotropica ◽  
2003 ◽  
Vol 35 (4) ◽  
pp. 550-555 ◽  
Author(s):  
Cesar Aponte ◽  
Guillermo R. Barreto ◽  
John Terborgh
Keyword(s):  
Life History ◽  
Habitat Fragmentation ◽  
Age Structure

Dynamics of an Exploited Population of Lake Whitefish (Coregonus clupeaformis)

1977 ◽  
Vol 34 (7) ◽  
pp. 942-953 ◽  
Author(s):  
Graham Bell ◽  
Paul Handford ◽  
Carl Dietz
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Age Structure ◽  
Annual Rate ◽  
Multiple Regression Equation ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
History Of ◽  
Almost All ◽  
Key Words Population Dynamics

The life history of the exploited lake whitefish (Coregonus clupeaformis) population of Lesser Slave Lake, Alberta, is described. Mean age is high, having increased under continued exploitation during the last 30 yr. A method of estimating the population age structure is described. The apparent annual rate of survival of adult fish has fluctuated markedly, but on average seems to lie in the interval 0.40–0.50; the annual rate of natural survival is estimated to be 0.53. Juveniles survive better than adults. Rate of survival during the 1st yr of life was estimated to be about 0.0002. Maturity was late, the median age at first reproduction being 6–61/2 yr. The regressions of fecundity on age and length are described; length now contributes almost all the attributable variance to maturity and fecundity. The sex ratio fluctuates in time; this is caused by the fluctuations in age structure, since sex ratio varies with age. The relationship between sex ratio and age is used to calculate the relative rates of survival of male and female fish.These data are used to construct a life table and to compute population parameters. It is inferred that the ability of the population to respond to exploitation has been eroded during the last 30 yr. In some respects, the life history of the Lesser Slave Lake stock appears to be unusual.After about 30 yr of large-amplitude oscillation the whitefish population collapsed in 1965. This does not seem to have been caused by chronic overfishing. In the first place, the rate of fishing mortality is no more than moderate. Secondly, a multiple regression equation describing whitefish catch in 48 other Alberta lakes in which there has been no overall decline in catch successfully predicts the observed mean catch at Lesser Slave Lake. The oscillations in catch are claimed to reflect a limit cycle in the abundance of the whitefish, driven by a lagged relationship between a predator (the fishermen) and its prey (the whitefish). Whether or not this cycle was deterministically stable, such behavior will inevitably put the population in risk of extinction during troughs in the cycle. We suggest that current management policies may encourage the destabilization of whitefish populations, and we propose a remedy. Key words: population dynamics, population regulation, life history, exploitation, survival, fecundity, Coregonus clupeaformis

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