scholarly journals Drought frequency predicts life history strategies in Heliophila

2018 ◽  
Author(s):  
J. Grey Monroe ◽  
Brian Gill ◽  
Kathryn Turner ◽  
John K McKay
Keyword(s):  
Life History ◽  
Life Histories ◽  
Evolutionary Biology ◽  
Life History Theory ◽  
Life History Strategy ◽  
Empirical Support ◽  
Life History Strategies ◽  
Perennial Species ◽  
Drought Frequency ◽  
Occurrence Records

Explaining variation in life history strategies is a long-standing goal of evolutionary biology. For plants, annual and perennial life histories are thought to reflect adaptation to environments that differ in the frequency of stress events such as drought. Here we test this hypothesis in Heliophila (Brassicaceae), a diverse genus of flowering plants native to Africa, by integrating 34 years of satellite-based drought measurements with 2192 herbaria occurrence records. Consistent with predictions from classic life history theory, we find that perennial Heliophila species occur in environments where droughts are significantly less frequent compared to annuals. These associations are predictive while controlling for phylogeny, lending support to the hypothesis that drought related natural selection has influenced the distributions of these strategies. Additionally, the collection dates of annual and perennial species indicate that annuals escape drought prone seasons during the seed phase of their life cycle. Together, these findings provide empirical support for classic hypotheses about the drivers of life history strategy in plants - that perennials out compete annuals in environments with less frequent drought and that annuals are adapted to environments with more frequent drought by escaping drought prone seasons as seeds.

Life History Strategies

2018 ◽  
pp. 95-126
Author(s):  
Marco Del Giudice
Keyword(s):  
Life History ◽  
Individual Differences ◽  
Life History Theory ◽  
Human Life ◽  
Life History Strategy ◽  
Current Theory ◽  
Life History Strategies ◽  
Extended Model ◽  
Life History Variation ◽  
Basic Model

The chapter introduces the basics of life history theory, the concept of life history strategy, and the fast–slow continuum of variation. After reviewing applications to animal behavior and physiology, the chapter reviews current theory and evidence on individual differences in humans as manifestations of alternative life history strategies. The chapter first presents a “basic model” of human life history–related traits, then advances an “extended model” that identifies multiple cognitive-behavioral profiles within fast and slow strategies. Specifically, it is proposed that slow strategies comprise prosocial/caregiving and skilled/provisioning profiles, whereas fast strategies comprise antisocial/exploitative and seductive/creative profiles. The chapter also reviews potential neurobiological markers of life history variation and considers key methodological issues in this area.

scholarly journals Between semelparity and iteroparity: empirical evidence for a continuum of modes of parity

2017 ◽  
Author(s):  
P. William Hughes
Keyword(s):  
Life History ◽  
Mathematical Models ◽  
Molecular Basis ◽  
Life Histories ◽  
Life History Theory ◽  
Reproductive Effort ◽  
Theoretical Biology ◽  
Relative Fitness ◽  
Life History Strategies ◽  
Molecular Evidence

ABSTRACTThe number of times an organism reproduces (i.e. its mode of parity) is a fundamental life-history character, and evolutionary and ecological models that compare the relative fitness of strategies are common in life history theory and theoretical biology. Despite the success of mathematical models designed to compare intrinsic rates of increase between annual-semelparous and perennial-iteroparous reproductive schedules, there is widespread evidence that variation in reproductive allocation among semelparous and iteroparous organisms alike is continuous. This paper reviews the ecological and molecular evidence for the continuity and plasticity of modes of parity––that is, the idea that annual-semelparous and perennial-iteroparous life histories are better understood as endpoints along a continuum of possible strategies. I conclude that parity should be understood as a continuum of different modes of parity, which differ by the degree to which they disperse or concentrate reproductive effort in time. I further argue that there are three main implications of this conclusion: (1) That seasonality should not be conflated with parity; (2) that mathematical models purporting to explain the evolution of semelparous life histories from iteroparous ones (or vice versa) should not assume that organisms can only display either an annual-semelparous life history or a perennial-iteroparous one; and (3) that evolutionary ecologists should examine the physiological or molecular basis of traits underlying different modes of parity, in order to obtain a general understanding of how different life history strategies can evolve from one another.

Divergent life histories and other ecological adaptations: Examples of social-class differences in attention, cognition, and attunement to others

2017 ◽  
Vol 40 ◽  
Author(s):  
Igor Grossmann ◽  
Michael E. W. Varnum
Keyword(s):  
Socioeconomic Status ◽  
Life History ◽  
Social Class ◽  
Life Histories ◽  
Life History Theory ◽  
Psychological Effects ◽  
Life History Strategies ◽  
Class Differences ◽  
Ecological Adaptations

AbstractMany behavioral and psychological effects of socioeconomic status (SES), beyond those presented by Pepper & Nettle cannot be adequately explained by life-history theory. We review such effects and reflect on the corresponding ecological affordances and constraints of low- versus high-SES environments, suggesting that several ecology-specific adaptations, apart from life-history strategies, are responsible for the behavioral and psychological effects of SES.

scholarly journals Life history strategies explain bacterial activity in the soil carbon cycle

2021 ◽  
Author(s):  
Samuel E. Barnett ◽  
Nicholas D. Youngblut ◽  
Chantal N. Koechli ◽  
Daniel H. Buckley
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Life History Strategy ◽  
Community Response ◽  
Stable Isotope Probing ◽  
Bacterial Activity ◽  
Life History Strategies ◽  
Soil System ◽  
C Cycle ◽  
C Assimilation

AbstractSoil microorganisms determine the fate of soil organic matter (SOM), and their activities comprise a major component of the global carbon (C) cycle. We sought to comprehend the physiological and ecological mechanisms underpinning microbial contributions to SOM dynamics by examining the activities of individual microorganisms within a complex soil system. We determined bacterial activity by using a multi-substrate DNA-stable isotope probing experiment to track C assimilation dynamics across thousands of bacteria within an agricultural soil. In this way, we identified 1,286 bacterial taxa assimilating C from SOM. Substrate bioavailability explained significant variation in mineralization rates and microbial assimilation dynamics. We show that, while patterns of C assimilation exhibited little phylogenetic conservation above the species level, these patterns defined functional clusters whose properties exemplified broad differences in life history strategy, particularly along the copiotroph-oligotroph continuum. We also show that these functional clusters explain soil community response to fresh litter, and patterns of microbial biogeography at continental and global scales. Our results add to the growing body of knowledge indicating that life history theory provides a useful framework for understanding microbial contributions to terrestrial C-cycling.

scholarly journals Do human ‘life history strategies’ exist?

2020 ◽  
Author(s):  
Rebecca Sear
Keyword(s):  
Social Sciences ◽  
Life History ◽  
Risk Taking ◽  
Life Histories ◽  
Life History Traits ◽  
Human Life ◽  
Environmental Influences ◽  
Life History Strategy ◽  
Life History Strategies ◽  
Human Sciences

Interest in incorporating life history research from evolutionary biology into the human sciences has grown rapidly in recent years. Two core features of this research have the potential to prove valuable in strengthening theoretical frameworks in the health and social sciences: the idea that these is a fundamental trade-off between reproduction and health; and that environmental influences are important in determining individual life histories. For example, the idea that mortality risk in the environment shifts individuals along a ‘fast-slow continuum’ of ‘life history strategy’ is now popular in the evolutionary human sciences. In biology, ‘fast’ life history strategists prioritise reproduction over health so that individuals grow quickly, reproduce early and often, and suffer a rapid deterioration in health and relatively early death; ‘slow’ strategists start reproducing later, have fewer offspring, and die at an older age. Evolutionary human scientists tend to assume that, along with these life history outcomes, several behavioural traits, such as parenting, mating and risk-taking behaviour and, in the most expansive version, a whole suite of psychological and personality traits also cluster together into ‘fast’ and ‘slow’ life histories. Here, I review the different approaches to life history strategies from evolutionary anthropologists, developmental psychologists and evolutionary psychologists, in order to assess the theoretical and empirical evidence for human ‘life history strategies’. While there is precedent in biology for the argument that some behavioural traits, notably risk-taking behaviour, may be linked in predictable ways with life history outcomes, there is relatively little theoretical or empirical justification for including a very wide range of behavioural traits in a ‘life history strategy’. Given the diversity and lack of consistency in this human life history literature, I then make recommendations for improving its usefulness: 1) greater clarity over terminology, so that a distinction is made between life history outcomes such as age at maturity, first birth and death, and behavioural traits which may be associated with life history outcomes but are not life history traits themselves; 2) more empirical data on linkages between life history traits, behavioural traits and the environment, including the underlying mechanisms which generate these linkages; 3) more empirical work on life history strategies in a much broader range of populations than has so far been studied. Such a research programme on human life history has the potential to produce valuable insights for the health and social sciences, not least because of its interest in environmental influences on health, reproduction and behaviour.

The Evolution of Annual and Perennial Plant Life Histories: Ecological Correlates and Genetic Mechanisms

2020 ◽  
Vol 51 (1) ◽  
pp. 461-481 ◽  
Author(s):  
Jannice Friedman
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Theory ◽  
Life History Strategies ◽  
Developmental Genetics ◽  
Evolutionary Transitions ◽  
Perennial Plant ◽  
Genetic Mechanisms ◽  
Future Reproduction ◽  
One Year

Flowering plants exhibit two principal life-history strategies: annuality (living and reproducing in one year) and perenniality (living more than one year). The advantages of either strategy depend on the relative benefits of immediate reproduction balanced against survivorship and future reproduction. This trade-off means that life-history strategies are associated with particular environments, with annuals being found more often in unpredictable habitats. Annuality and perenniality are the outcome of developmental genetic programs responding to their environment, with perennials being distinguished by their delayed competence to flower and reversion to growth after flowering. Evolutionary transitions between these strategies are frequent and have consequences for mating systems and genome evolution, with perennials being more likely to outcross with higher inbreeding depression and lower rates of molecular evolution. Integrating expectations from life-history theory with knowledge of the developmental genetics of flowering and seasonality is required to understand the mechanisms involved in the evolution of annual and perennial life histories.

scholarly journals Implications of life-history strategies for obesity

2017 ◽  
Vol 114 (32) ◽  
pp. 8517-8522 ◽  
Author(s):  
Jon K. Maner ◽  
Andrea Dittmann ◽  
Andrea L. Meltzer ◽  
James K. McNulty
Keyword(s):  
Socioeconomic Status ◽  
Life History ◽  
Low Socioeconomic Status ◽  
Life History Theory ◽  
Eating Behaviors ◽  
Behavioral Science ◽  
Life History Strategy ◽  
High Body Mass Index ◽  
Life History Strategies ◽  
Weight Problems

The association between low socioeconomic status (SES) and obesity is well documented. In the current research, a life history theory (LHT) framework provided an explanation for this association. Derived from evolutionary behavioral science, LHT emphasizes how variability in exposure to unpredictability during childhood gives rise to individual differences in a range of social psychological processes across the life course. Consistent with previous LHT research, the current findings suggest that exposure to unpredictability during childhood (a characteristic common to low SES environments) is associated with the adoption of a fast life-history strategy, one marked by impulsivity and a focus on short-term goals. We demonstrate that a fast life-history strategy, in turn, was associated with dysregulated weight-management behaviors (i.e., eating even in the absence of hunger), which were predictive of having a high body mass index (BMI) and being obese. In both studies, findings held while controlling for participants’ current socioeconomic status, suggesting that obesity is rooted in childhood experiences. A serial mediation model in study 2 confirmed that effects of childhood SES on adult BMI and obesity can be explained in part by exposure to unpredictability, the adoption of a fast life-history strategy, and dysregulated-eating behaviors. These findings suggest that weight problems in adulthood may be rooted partially in early childhood exposure to unpredictable events and environments. LHT provides a valuable explanatory framework for understanding the root causes of obesity.

scholarly journals A complex interplay between balancing selection and introgression maintains a genus-wide alternative life-history strategy.

2021 ◽  
Author(s):  
kalle tunström ◽  
Alyssa Woronik ◽  
Joseph J Hanly ◽  
Pasi Rastas ◽  
Anton Chichvarkhin ◽  
...  
Keyword(s):  
Life History ◽  
Life Histories ◽  
Balancing Selection ◽  
Genetic Locus ◽  
Regulatory Region ◽  
Life History Strategy ◽  
Life History Strategies ◽  
Pigment Synthesis ◽  
Evolutionary Forces

Alternative life-history strategies (ALHS) are genetic polymorphisms generating phenotypes differing in life histories that generally arise due to metabolic resource allocation tradeoffs. Althouigh ALHS are often be limited to a single sex or populations of a species, they can, in rare cases, be found among several species across a genus. In the butterfly genus Colias, at least a third of the species have a female limited ALHS called Alba. While many females develop brightly pigmented wings, Alba females reallocate nitrogen resources used in pigment synthesis to reproductive development, producing white-winged, more fecund females. Whether this ALHS evolved once or many times, and whether it has moved among species via introgression or been maintained via long-term balancing selection, has not been established. Answering these questions presents an opportunity to investigate the genetic basis and evolutionary forces acting upon ALHS, which have rarely been studied at a genus level. Here we identify the genetic locus of Alba in a second Colias species, allowing us to compare this with previous results in a larger phylogenetic context. Our findings suggest Alba has a singular origin and has been maintained in Colias through a combination of balancing selection and introgression for nearly one million years and at least as many generations. Finally, using CRISPR/Cas9 deletions in the cis-regulatory region of the Alba allele, we demonstrate that the Alba allele is a modular enhancer for the BarH1 gene and is necessary for the induction of the ALHS, which potentially facilitates its long-term persistence in the genus.

Effect of time of day, time of year, and life history strategy on time budgeting in juvenile Atlantic salmon, Salmo salar

1999 ◽  
Vol 56 (12) ◽  
pp. 2397-2403 ◽  
Author(s):  
Sveinn K Valdimarsson ◽  
Neil B Metcalfe
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Life History Strategy ◽  
Time Of Day ◽  
Life History Strategies ◽  
Foraging Efficiency ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Time Of Year

Traditionally, behavioural studies on juvenile Atlantic salmon, Salmo salar, have been conducted during the day in summer. It is known that Atlantic salmon become nocturnal in winter, but very little is known about their behaviour at that time. Therefore, observations in a seminatural stream were carried out during the day and night, from February to June, comparing diel and seasonal differences in behaviour between fish adopting alternative life history strategies. The results showed a general trend for more activity in spring than in winter, and the fish were found to be foraging at surprisingly low light levels. There were differences in relative feeding rate between the life history strategies; the early migrant fish foraged mostly during the day whereas the delayed migrant fish did more foraging at night. There is some evidence that the early migrant fish made fewer feeding attempts over the winter, which is surprising, since they grow faster over that period. This suggests differences in foraging efficiency, which could contribute to the separation into these two life history strategies.

Sexual size dimorphism and life history traits in an island-mainland system: an overview of the lizard genus Microlophus

2021 ◽  
pp. 1-7
Author(s):  
Ken S. Toyama ◽  
Christopher K. Boccia
Keyword(s):  
Life History ◽  
South America ◽  
Life History Theory ◽  
Life History Traits ◽  
Sexual Size Dimorphism ◽  
Life History Strategies ◽  
Galápagos Islands ◽  
Size Dimorphism ◽  
Rensch's Rule ◽  
Comprehensive Compilation

Abstract Opposing life history strategies are a common result of the different ecological settings experienced by insular and continental species. Here we present a comprehensive compilation of data on sexual size dimorphism (SSD) and life history traits of Microlophus, a genus of lizards distributed in western South America and the Galápagos Islands, and test for differences between insular and continental species under life history theory expectations. Contrary to our predictions, we found no differences in SSD between localities or evidence that Microlophus follows Rensch’s rule. However, as expected, head dimensions and maturity sizes were significantly larger in insular species while continental species had larger clutches. Our results show that Microlophus exhibits some of the patterns expected from an island-mainland system, but unexplained patterns will only be resolved through future ecological, morphological and behavioural studies integrating both faunas.

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