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1.
Sinéad Collins 《Evolutionary biology》2011,38(1):3-14
Experimental microbial evolution has focused on the particular ecological scenario where a population is placed suddenly in
an environment where its fitness is low, and then adapts while the environment remains stable. In line with this, most microbial
evolution studies use fitness measures that report how evolved genotypes fare when competed directly against their own distant
ancestor while other studies compare life history traits (such as growth rates) of ancestral and evolved genotypes. This standard
way of measuring and reporting changes in fitness has resulted in a consistent body of literature that explains adaptation
when populations evolve in this “standard ecological scenario.” Here, I suggest that for experimental evolution to investigate
adaptation in other ecological scenarios, such as fluctuating or persistently changing environments, measures of fitness must
be expanded such that they not only continue to be comparable between experiments, but also account for evolution and demographic
effects in all environments that an evolving lineage experiences. I examine two non-standard measures of fitness—fitness flux
and the total number of reproductive events—as potential ways to quantify adaptation by integrating historical information
about selection over many environments. This approach could allow us to make quantitative and biologically-meaningful comparisons
of adaptation across diverse ecological scenarios. I use the case study of understanding how phytoplankton communities may
respond to global change, where environmental variables change continuously, to explore concrete ways of using non-standard
fitness measures that consider both demographic effects and selection in changing, rather than in changed, environments. 相似文献
2.
Laura K. Lopez Michael A. Gil Philip H. Crowley Pete C. Trimmer Amelia Munson Isaac Y. Ligocki Marcus Michelangeli Andrew Sih 《Biological reviews of the Cambridge Philosophical Society》2023,98(4):1345-1364
While a large body of research has focused on the physiological effects of multiple environmental stressors, how behavioural and life-history plasticity mediate multiple-stressor effects remains underexplored. Behavioural plasticity can not only drive organism-level responses to stressors directly but can also mediate physiological responses. Here, we provide a conceptual framework incorporating four fundamental trade-offs that explicitly link animal behaviour to life-history-based pathways for energy allocation, shaping the impact of multiple stressors on fitness. We first address how small-scale behavioural changes can either mediate or drive conflicts between the effects of multiple stressors and alternative physiological responses. We then discuss how animal behaviour gives rise to three additional understudied and interrelated trade-offs: balancing the benefits and risks of obtaining the energy needed to cope with stressors, allocation of energy between life-history traits and stressor responses, and larger-scale escape from stressors in space or time via large-scale movement or dormancy. Finally, we outline how these trade-offs interactively affect fitness and qualitative ecological outcomes resulting from multiple stressors. Our framework suggests that explicitly considering animal behaviour should enrich our mechanistic understanding of stressor effects, help explain extensive context dependence observed in these effects, and highlight promising avenues for future empirical and theoretical research. 相似文献
3.
Humans use metaphors to explore their relationship with nature. Our ability to make and understand metaphors appears to be
an automatic cognitive process, one that likely evolved along with our ability to create and understand language. Because
metaphors are processed automatically, without conscious appraisal, they can be used to rapidly communicate, or manipulate.
Applying theories of evolutionary psychology and cognitive science to literary texts, we explored the role of animal metaphors
in the making and partaking of stories in the context of a course in environmental studies. We investigated how humans are
animals and yet use culture to shield themselves from this reality. We read and analyzed literature in which animal metaphors
are central, such as Honoré de Balzac’s short story Passion in the Desert and Langdon Smith’s poem “Evolution.” Throughout the course, the overarching theme is that animal metaphors are powerful
tools for framing our relationship with the environment and that they can be best understood in the context of humans as evolved
animals. 相似文献
4.
Ryan J. Burke Jay M. Fitzsimmons Jeremy T. Kerr 《Biodiversity and Conservation》2011,20(10):2273-2295
Mobility is a key component of species’ biology. Research on mobility is inherently difficult, however, resulting in studies
of narrow taxonomic, spatial, and temporal scope with results that are difficult to compare between studies. We had three
goals for our research: (1) construct a data set of mobility estimates for the butterfly species of Canada based on naturalists’
knowledge; (2) develop methods to evaluate aspects of accuracy and precision for knowledge-based ecological research such
as ours; and (3) using our data set, test mobility-related hypotheses of species-level relationships. We distributed a questionnaire
to amateur and professional lepidopterists in Canada and northern USA, asking them to estimate the mobility of Canadian butterfly
species based on their field experience. Based on responses from 51 lepidopterists with approximately 800 years of combined
field experience, we received mobility estimates for almost all (291 out of 307) of Canada’s butterfly taxa. Mobility estimates
were consistent among respondents and were not affected by respondent expertise. Mobility carries a strong phylogenetic signal
and is positively related to wingspan (albeit weakly), range size, and host plant breadth, and negatively related to conservation
risk. Reliance upon naturalists’ experience was essential to the feasibility of our project, and provides a promising method
for many types of ecological research. 相似文献
5.
Life-history studies provide a global framework for comparison of fish species responses and trade-offs facing ecological
and environmental constrains. A broad comparison among fishes’ early growth and condition traits is performed in order to
determine ecological patterns of early development regarding latitudinal distribution, habitat use and life-history strategies.
Based on Winemiller and Rose (1992) classification of life-history strategies, data on early growth and condition indices of 46 fish species worldwide was analysed.
Available information on fishes’ early features, namely first year length percentage (relative to species maximum theoretical
length), age at maturation and Fulton’s condition index (K), provided a good segregation of species by latitudinal distribution and habitat use, and evidenced the categories of the
three-endpoint model. Higher larvae and juvenile growth rates and condition indices (K, mean RNA–DNA ratios and protein contents) were associated with tropical and temperate fish species that occur in complex
or variable habitats (respectively coral reefs and estuaries). These species selected for the opportunistic and periodic strategies,
investing highly in rapid growth in order to increase survival probability to counter high mortality rates during early stages
or unstable habitat conditions. Later age at maturation, slower larvae and juvenile growth as well as lower mean condition
indices were consistent with fish species from more stable or predictable environments, as polar regions and freshwater habitats,
which selected for the equilibrium strategy. Nonetheless, differences in energy allocation strategies during early stages
were not observed, evidencing the scarcity of available data regarding condition indices and/or the importance of integrating
life-history intermediate strategies. Future research into condition indices and other physiological processes, for a broader
set of species and for a wider latitudinal and habitat range including seasonal variability (particularly for species from
tropical and polar regions), is essential to better understand or test current theories of species ecological patterns. The
use of direct quantitative measures of young fishes’ metabolic investment and fitness constitutes a new approach for life-history
studies, and should be fundamental for predicting species’ responses to acute environmental or human constrains, especially
in a global climate change scenario that is expected to affect distribution and abundance of fish species worldwide. 相似文献
6.
We investigate the interaction of learning and evolution in a changing environment. A stable learning capability is regarded
as an emergent adaptive system evolved by natural selection of genetic variants. We consider the evolution of an asexual population.
Each genotype can have ‘fixed’ and ‘flexible’ alleles. The former express themselves as synaptic connections that remain unchanged
during ontogeny and the latter as synapses that can be adjusted through a learning algorithm. Evolution is modelled using
genetic algorithms and the changing environment is represented by two optimal synaptic patterns that alternate a fixed number
of times during the ‘life’ of the individuals. The amplitude of the change is related to the Hamming distance between the
two optimal patterns and the rate of change to the frequency with which both exchange roles. This model is an extension of
that of Hinton and Nowlan in which the fitness is given by a probabilistic measure of the Hamming distance to the optimum.
We find that two types of evolutionary pathways are possible depending upon how difficult (costly) it is to cope with the
changes of the environment. In one case the population loses the learning ability, and the individuals inherit fixed synapses
that are optimal in only one of the environmental states. In the other case a flexible subsystem emerges that allows the individuals
to adapt to the changes of the environment. The model helps us to understand how an adaptive subsystem can emerge as the result
of the tradeoff between the exploitation of a congenital structure and the exploration of the adaptive capabilities practised
by learning. 相似文献
7.
Marshall Abrams 《Biology & philosophy》2009,24(4):487-504
It’s recently been argued that biological fitness can’t change over the course of an organism’s life as a result of organisms’
behaviors. However, some characterizations of biological function and biological altruism tacitly or explicitly assume that
an effect of a trait can change an organism’s fitness. In the first part of the paper, I explain that the core idea of changing
fitness can be understood in terms of conditional probabilities defined over sequences of events in an organism’s life. The
result is a notion of “conditional fitness” which is static but which captures intuitions about apparent behavioral effects
on fitness. The second part of the paper investigates the possibility of providing a systematic foundation for conditional
fitness in terms of spaces of sequences of states of an organism and its environment. I argue that the resulting “organism–environment
history conception” helps unify diverse biological perspectives, and may provide part of a metaphysics of natural selection.
相似文献
Marshall AbramsEmail: |
8.
Phytoplankton stoichiometry 总被引:2,自引:0,他引:2
Because phytoplankton live at the interface between the abiotic and the biotic compartments of ecosystems, they play an important
role in coupling multiple nutrient cycles. The quantitative details of how these multiple nutrient cycles intersect is determined
by phytoplankton stoichiometry. Here we review some classic work and recent advances on the determinants of phytoplankton
stoichiometry and their role in determining ecosystem stoichiometry. First, we use a model of growth with flexible stoichiometry
to reexamine Rhee and Goldman’s classic chemostat data. We also discuss a recent data compilation by Hall and colleagues that
illustrates some limits to phytoplankton flexibility, and a model of physiological adaptation that can account for these results.
Second, we use a model of resource allocation to determine the how the optimal nitrogen-to-phosphorus stoichiometry depends
on the ecological conditions under which species grow and compete. Third, we discuss Redfield’s mechanism for the homeostasis
of the oceans’ nitrogen-to-phosphorus stoichiometry and show its robustness to additional factors such as iron-limitation
and temporal fluctuations. Finally, we suggest areas for future research. 相似文献
9.
10.
Edgar G. Hertwich James K. Hammitt 《The International Journal of Life Cycle Assessment》2001,6(5):265-272
In the first part of this paper, we showed how life-cycle impact assessment can be described as an exercise in decision analysis. We developed a structure for how to decide on the relative importance of different environmental stressors. In this second part, we offer criteria for the grouping of stressors into impact categories and for the development of impact indicators. Facts to be included in a characterization method should be selected according to their relevance and combined following established scientific models. Facts should be included only if they are informative, that is, if sufficient and sufficiently certain information is available for all stressors that should be evaluated by this method. Abstract, constructed indicators at the ‘midpoint level’ are better suited to compare similar impacts than indicators reflecting ‘observable environmental endpoints’ if there is a large uncertainty about the effects on observable endpoints. We argue that midpoint modeling should be retained. The additional evidence introduced by endpoint methods should be used to support ‘judgments about facts’ needed to evaluate the importance of different impact categories (or means objectives) in the means-ends objectives network. 相似文献
11.
Modest increases in global temperature have been implicated in causing population extirpations and range shifts in taxa inhabiting
colder environs and in ectotherms whose thermoregulation is more closely tied to environmental conditions. Many arid-adapted
endotherms already experience conditions at their physiological limits, so it is conceivable that they could be similarly
affected by warming temperatures. We explored how climatic variables might influence the apparent survival of the banner-tailed
kangaroo rat (Dipodomys spectabilis), a rodent endemic to the Chihuahuan Desert of North America and renowned for its behavioral and physiological adaptations
to arid environments. Relative variable weight, strength of variable relationships, and other criteria indicated that summer,
diurnal land surface temperature (SD_LST) was the primary environmental driver of apparent survival in these arid-adapted
rodents. Higher temperatures had a negative effect on apparent survival, which ranged from 0.15 (SE = 0.04) for subadults
to 0.50 (SE = 0.07) for adults. Elevated SD_LST may negatively influence survival through multiple pathways, including increased
water loss and energy expenditure that could lead to chronic stress and/or hyperthermia that could cause direct mortality.
Land surface temperatures are predicted to increase by as much 6.5°C by 2099, reducing apparent survival of adults to ~0.15
in some regions of the species’ range, possibly causing a shift in their distribution. The relationship between SD_LST and
survival suggests a mechanism whereby physiological tolerances are exceeded resulting in a reduction to individual fitness
that may ultimately cause a shift in the species’ range over time. 相似文献
12.
In our previous report [Aita, T., Morinaga, S., Hosimi, Y., 2004. Thermodynamical interpretation of evolutionary dynamics
on a fitness landscape in an evolution reactor I. Bull. Math. Biol. 66, 1371–1403], an analogy between thermodynamics and
adaptive walks on a Mt. Fuji-type fitness landscape in an artificial selection system was presented. Introducing the ‘free
fitness’ as the sum of a fitness term and an entropy term and ‘evolutionary force’ as the gradient of free fitness on a fitness
coordinate, we demonstrated that the adaptive walk (=evolution) is driven by the evolutionary force in the direction in which
free fitness increases. In this report, we examine the effect of various modifications of the original model on the properties
of the adaptive walk. The modifications were as follows: first, mutation distance d was distributed obeying binomial distribution; second, the selection process obeyed the natural selection protocol; third,
ruggedness was introduced to the landscape according to the NK model; fourth, a noise was included in the fitness measurement. The effect of each modification was described in the same
theoretical framework as the original model by introducing ‘effective’ quantities such as the effective mutation distance
or the effective screening size. 相似文献
13.
Harold Levrel Christian Kerbiriou Denis Couvet Jacques Weber 《Biodiversity and Conservation》2009,18(7):1719-1732
Sustainability is said to be the science of integration, be it integration of scale, discipline or of stakeholders’ interests.
One way to integrate such diverse elements is to develop sustainable development indicators. Numerous national and international
organizations have attempted to develop such indicators, among which interaction indicators are of critical importance because
they enable us to link up human activities, ecological dynamics, and social goals. Among the various ways to develop such
indicators, the most common ones are the pressure–state–response (PSR) indicators, as well as others coming from this framework.
With realistic methodology one shall observe how PSR indicators might appear as an operational tool to face rapid social and
ecological changes within a French biosphere reserve in Brittany. Results suggest that such a framework is insufficient to
describe, understand and manage social and ecological interactions.
相似文献
Harold LevrelEmail: |
14.
A theory for describing evolution as adaptive walks by a finite population with M walkers (M ≥ 1) on an anisotropic Mt. Fuji-type fitness landscape is presented, from a thermodynamical point of view. Introducing the
‘free fitness’ as the sum of a fitness term and an entropy term and ‘evolutionary force’ as the gradient of free fitness on
a fitness coordinate, we demonstrate that the behavior of these theoretical walkers is almost consistent with the thermodynamical
schemes. The major conclusions are as follows: (1) an adaptive walk (=evolution) is driven by an evolutionary force in the
direction in which free fitness increases; (2) the expectation of the climbing rate obeys an equation analogous to the Einstein
relation in Brownian motion; (3) the standard deviation of the climbing rate is a quantity analogous to the mean thermal energy
of a particle, kT (×constant). In addition, on the interpretation that the walkers climb the landscape by absorbing ‘fitness information’ from
the surroundings, we succeeded in quantifying the fitness information and formulating a macroscopic scheme from an informational
point of view. 相似文献
15.
Marshall Abrams 《Biology & philosophy》2007,22(1):115-130
Recent debate on the nature of probabilities in evolutionary biology has focused largely on the propensity interpretation
of fitness (PIF), which defines fitness in terms of a conception of probability known as “propensity”. However, proponents
of this conception of fitness have misconceived the role of probability in the constitution of fitness. First, discussions
of probability and fitness have almost always focused on organism effect probability, the probability that an organism and its environment cause effects. I argue that much of the probability relevant to fitness
must be organism circumstance probability, the probability that an organism encounters particular, detailed circumstances within an environment, circumstances which
are not the organism’s effects. Second, I argue in favor of the view that organism effect propensities either don’t exist
or are not part of the basis of fitness, because they usually have values close to 0 or 1. More generally, I try to show that
it is possible to develop a clearer conception of the role of probability in biological processes than earlier discussions
have allowed. 相似文献
16.
K. E. Boes 《Insectes Sociaux》2010,57(1):1-9
Social insect colonies display a remarkable ability to adjust investment in reproduction (i.e., production of sexuals) in
accordance with environmental conditions such as season and food availability. How this feat is accomplished by the colony’s
queen(s) and workers remains a puzzle. Here, I review what we have learned about this subject in the European honeybee (Apis mellifera), specifically with regard to a colony’s production of males (drones). I identify five environmental conditions that influence
colony-level patterns of drone production and then define five stages of drone rearing that are accomplished by the queen
and workers. Using this framework, I detail our current understanding of how the queen or workers adjust their actions at
each stage of drone rearing in response to each of the environmental conditions. Future investigations of this topic in honeybees
and other social insect societies will lead to a better understanding of how colonies manage to flexibly and efficiently allocate
their resources under changing environmental conditions. 相似文献
17.
Niclas U. Lundsgaard Coen Hird Kathleen A. Doody Craig E. Franklin Rebecca L. Cramp 《Global Change Biology》2023,29(14):3857-3868
Ecological carryover effects, or delayed effects of the environment on an organism's phenotype, are central predictors of individual fitness and a key issue in conservation biology. Climate change imposes increasingly variable environmental conditions that may be challenging to early life-history stages in animals with complex life histories, leading to detrimental physiological and fitness effects in later life. Yet, the latent nature of carryover effects, combined with the long temporal scales over which they can manifest, means that this phenomenon remains understudied and is often overlooked in short-term studies limited to single life-history stages. Herein, we review evidence for the physiological carryover effects induced by elevated ultraviolet radiation (UVR; 280–400 nm) as a potential contributor to recent amphibian population declines. UVR exposure causes a suite of molecular, cellular and physiological consequences known to underpin carryover effects in other taxa, but there is a lack of research linking embryonic and larval UVR exposures to fitness consequences post-metamorphosis in amphibians. We propose that the key impacts of UVR on disease-related amphibian declines are facilitated through carryover effects that bridge embryonic and larval UVR exposure with potential increased disease susceptibility post-metamorphosis. We conclude by identifying a practical direction for the study of ecological carryover effects in amphibians that could guide future ecological research in the broader field of conservation physiology. Only by addressing carryover effects can many of the mechanistic links between environmental change and population declines be elucidated. 相似文献
18.
Under the U.S. Environmental Protection Agency’s mission to protect human health and the environment, the agency seeks to
conduct research on the structure and function of ecosystems and to improve our understanding of the processes that contribute
to the sustained health of the nation’s ecosystems and the well-being of human populations. Changes in biodiversity can profoundly
impact the ability of ecosystems to provide clean water, energy, food, recreation, and other services that contribute to human
well-being. In addition, changes in biodiversity can affect the transmission of infectious disease to humans, particularly
vectorborne diseases such as malaria and Lyme disease. The Environmental Protection Agency’s new initiative supports interdisciplinary
research to characterize the mechanisms that link biodiversity and human health and to use this knowledge to develop integrative
tools and approaches for quantifying and predicting these relationships. Research on these links can have an important impact
on our view of biodiversity and how we manage resources to protect human and ecosystem health.
Disclaimer: This work was funded in part under Grant #CX3-832328 with the American Association for the Advance of Science
(AAAS). The views expressed do not necessarily reflect the views of the Environmental Protection Agency. 相似文献
19.
Darren C. Hunter Josephine M. Pemberton Jill G. Pilkington Michael B. Morrissey 《Evolution; international journal of organic evolution》2018,72(4):851-866
In nature, selection varies across time in most environments, but we lack an understanding of how specific ecological changes drive this variation. Ecological factors can alter phenotypic selection coefficients through changes in trait distributions or individual mean fitness, even when the trait‐absolute fitness relationship remains constant. We apply and extend a regression‐based approach in a population of Soay sheep (Ovis aries) and suggest metrics of environment‐selection relationships that can be compared across studies. We then introduce a novel method that constructs an environmentally structured fitness function. This allows calculation of full (as in existing approaches) and partial (acting separately through the absolute fitness function slope, mean fitness, and phenotype distribution) sensitivities of selection to an ecological variable. Both approaches show positive overall effects of density on viability selection of lamb mass. However, the second approach demonstrates that this relationship is largely driven by effects of density on mean fitness, rather than on the trait‐fitness relationship slope. If such mechanisms of environmental dependence of selection are common, this could have important implications regarding the frequency of fluctuating selection, and how previous selection inferences relate to longer term evolutionary dynamics. 相似文献
20.
基于生态系统服务理论的中国绿色经济转型预测分析 总被引:2,自引:0,他引:2
着眼于中国绿色经济转型之路的科学预测与分析,借鉴传统环境负荷模型以及资源与经济脱钩理论、区位熵理论等,提出基于生态系统服务理论的有关绿色经济指标评价模型。应用该模型计算出2001—2010年全球及中国有关绿色经济指标,依照未来中国经济与社会发展规划目标,预计"十二五"末期中国经济发展中的资源消耗及环境损失成本、人均绿色GDP将分别达到3.11×1012美元、0.37×104美元,生态负荷强度、资源脱钩指数及绿色GDP的区位熵指数分别为0.38、0.66、75;2020年中国绿色GDP的区位熵指数将超越全球平均水平、2024年人均GDP将突破1万美元关口步入中等发达国家行列。计算结果表明中国生态系统压力逐年降低、资源利用效率、环境绩效与经济效益同步提高,逐渐在全球经济绿色转型过程中发挥重要作用;未来,中国仍需秉承"共同但有区别的责任"原则,处理好与其他国家的权责纷争;同时积极推进节能减排、经济结构调整工作,进一步协调好城乡之间、区域之间经济社会发展与自然资源及生态环境的关系。 相似文献