Evolutionary Ecological Perspective Research Articles

Differential responses of Bactrocera dorsalis and its parasitoids to headspaces of different varieties of tree-attached mango fruits and the associated chemical profiles

Bactrocera dorsalis (Hendel) is a major pest of fruits and vegetables worldwide with documented losses of up to 100%. Various management techniques including the use of parasitoids, such as Fopius arisanus (Sonan) and Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) within the context of the Integrated Pest Management (IPM) approach have been deployed for its control. The effectiveness of parasitoids is well understood, but knowledge of the semiochemicals that mediate their behavior, as well as that of the host fruit fly to tree-attached mangoes, is lacking. Here, we first compared the attractiveness of the above-mentioned fruit fly and its parasitoids to volatiles of different treatments (non-infested physiologically mature unripe and ripe mangoes, mangoes newly exposed to ovipositing B. dorsalis, and mangoes on day 7 and day 9 post-oviposition) of tree-attached Kent, Apple, and Haden mango varieties relative to control (clean air). The fruit fly was significantly more attracted to the mango volatiles (up to 93% of responsive insects) compared to the control (clean air). Fopius arisanus was significantly more attracted to mangoes with ovipositing fruit flies (68–76%) while D. longicaudata was significantly more attracted to day 9 post-oviposited mangoes (64–72%) compared to the control. Secondly, we elucidated the headspace volatile profiles of the non-infested and infested tree-attached mangoes using gas chromatography linked to mass spectrometry (GC-MS). The volatiles revealed various types of organic compounds with qualitative and quantitative differences. The majority of the compounds were esters making 33.8% of the total number, followed by sesquiterpenes-16.4%, and monoterpenes-15.4% among others. Most compounds had higher release rates in headspace volatiles of fruit fly-infested mangoes. Lastly, we harvested the infested mangoes and incubated them for puparia recovery. The number of puparia recovered varied according to the mango variety with Apple mango registering 81.7% of the total, while none was recovered from Kent. These results represent the first report of the changes in the headspace components of non-infested and infested tree-attached mangoes and the associated differential responses of the mentioned insects. A follow-up study can reveal whether there is a convergence in olfactomes which is significant when developing baits that selectively attract the fruit fly and not its natural enemies and fill the knowledge gap from an evolutionary ecological perspective.

Transgenerational effects and temperature variation alter life history traits of the moon jellyfish

Understanding the life history strategy of organisms is key to predicting their population dynamics. The population of scyphozoan jellyfish has displayed an increasing trend in recent decades, yet its life history strategy is not fully understood. To interpret the reproduction strategy of scyphozoan jellyfish from an evolutionary ecology perspective, we dissected 10 asexual generations of Aurelia coerulea polyps to investigate the relationships between transgenerational effects on their budding reproduction and strobilation. Our results reveal that a polyp’s average budding reproduction rate declined 32.82% through asexual generations within the experimental time. Furthermore, a longer culture duration counteracted the transgenerational effects on budding rates and strobilation afterward. Thus, this effort provides insight into the necessity of sexual reproduction in organisms involving a metagenic life cycle, i.e., to renew the asexual reproduction ability of a population. Besides this, we suggest taking note that it is necessary to know the “asexual age” of polyps when performing experimental studies and mathematical modeling to explore their population dynamics. Our results also present a valuable data set to interpret the evolution of the scyphozoan jellyfish’s life history strategy under multifactorial environments.

Invasive fish retain plasticity of naturally selected, but diverge in sexually selected traits

Invasive alien species (IAS) have become a major threat to ecosystems worldwide. From an evolutionary ecological perspective, they allow teasing apart the relative contributions of plasticity and evolutionary divergence in driving rapid phenotypic diversification. When IAS spread across extensive geographic ranges, climatic variation may represent a source of strong natural selection through overwinter mortality and summer heat stress. This could favour local adaptation, i.e., evolutionary divergence of certain traits. IAS, however, are likely to show plasticity in survival-related traits, and environmental fluctuation in their new distribution range could favour the maintenance of this pre-existing phenotypic plasticity. By contrast, sexually selected traits are more likely to undergo evolutionary divergence when components of sexual selection differ geographically. Here, using data from a common-garden rearing experiment of Western mosquitofish (Gambusia affinis Baird and Girard, 1853) from five populations across the species' invasive range in China, we show that invasive mosquitofish have retained plasticity in key physiological (thermal tolerances), morphological and life-history traits even 100 years after their introduction to China, but exhibit heritable population differences in several sexually selected traits, including the shape of the male copulatory organ. Adaptive plasticity of traits linked to immediate survival in different thermal environments—while likely responsible for the species' extraordinary invasion success—could slow down genetic evolution. Several sexually selected traits could diverge geographically and show rapid evolutionary change, e.g., because climate alters selective landscapes arising from mate competition as an indirect consequence of variation in overwinter mortality.

5. Attitudes on Investment in Descendants: Products of Evolution?

This study aims to examine intergenerational equity (concern for future generations) from a human evolutionary ecology perspective. The extent to which males and females differ in their concern about the welfare of future generations can be interpreted as a product of natural selection. We hypothesized that reproductive advantage is conferred upon males by discounting future generations and focusing on their immediate well being. Given that males potentially have many children, and do not invest the same resources in raising children, it is to their reproductive advantage to focus on the present and their own wellbeing, so that they can continue to reproduce. It is hypothesized that reproductive advantage would be conferred upon females who are concerned about future generations. Females potentially have fewer children and invest more in raising children. It is therefore more to their reproductive advantage to ensure that children survive to adulthood. Using a between‐subjects design online survey, emailed to individuals in the Queen's Community (Students, Staff, Faculty, and Alumni), we asked participants to indicate what proportion of available money ($10, 000 they received by chance) they would allocate to mitigating a hypothetical food crisis (collectivist option) versus to three “individualist” options. Participants were randomly assigned to hypothetical scenarios where the food crisis affected: the participant's generation, their children's generation, their grandchildren's generation, or their great‐ grandchildren's generation. In all four scenarios, we found that males invested significantly less in mitigating the food crisis than females. Additionally, we found that neither males nor females differed significantly between scenarios in the amount they invested in mitigating the food crisis.

The Life and Times of Parasites: Rhythms in Strategies for Within-host Survival and Between-host Transmission.

Biological rhythms are thought to have evolved to enable organisms to organize their activities according to the earth’s predictable cycles, but quantifying the fitness advantages of rhythms is challenging and data revealing their costs and benefits are scarce. More difficult still is explaining why parasites that live exclusively within the bodies of other organisms have biological rhythms. Rhythms exist in the development and traits of parasites, in host immune responses, and in disease susceptibility. This raises the possibility that timing matters for how hosts and parasites interact and, consequently, for the severity and transmission of diseases. Here, we take an evolutionary ecological perspective to examine why parasites exhibit biological rhythms and how their rhythms are regulated. Specifically, we examine the adaptive significance (evolutionary costs and benefits) of rhythms for parasites and explore to what extent interactions between hosts and parasites can drive rhythms in infections. That parasites with altered rhythms can evade the effects of control interventions underscores the urgent need to understand how and why parasites exhibit biological rhythms. Thus, we contend that examining the roles of biological rhythms in disease offers innovative approaches to improve health and opens up a new arena for studying host-parasite (and host-parasite-vector) coevolution.

Energy Intake, Basal Metabolic Rate, and Within-Individual Trade-Offs in Men and Women Training for a Half Marathon: A Reanalysis

Understanding the mechanisms governing energy budgets during periods of high energy expenditure is important from both an evolutionary physiology and behavioral ecology perspective. In particular, we still know too little about the linkages between key components such as daily energy expenditure (DEE), daily energy intake (DEI), and basal metabolic rate (BMR). Westerterp et al. repeatedly measured DEI (self-reported), BMR (respirometry), and body composition (fat mass) in 23 adult subjects as they transitioned from an inactive lifestyle and trained during 44 wk in preparation of running a half marathon. Here, I reanalyzed this data set using bivariate mixed models to partition the phenotypic correlation between DEI and BMR at the among- and within-individual levels. Reported DEI and BMR were positively correlated at the among-individual level (i.e., individuals with high average reported DEI also have a high average BMR). However, reported DEI and BMR were not correlated within individuals. There was a negative within-individual relationship between BMR and surplus energy (i.e., the energy intake above BMR = DEI - BMR), suggesting the presence of compensation mechanisms between BMR and other energy-demanding activities occurring within individuals. Thus, the principles governing energy budget were different at the among- and within-individual levels. To the extent that this situation is applicable to wild animals experiencing different levels of DEE throughout their annual cycle, the results presented here could explain why the relationships between BMR and other components of the energy budget (e.g., activity, growth, reproduction) are often context dependent.

Production and sex-pheromonal activity of alkaloid-derived androconial compounds in the danaine butterfly,Parantica sita(Lepidoptera: Nymphalidae: Danainae)

Close associations of certain lepidopteran taxa with pyrrolizidine alkaloids (PAs), a typical class of plant secondary metabolites, have been well documented from the perspective of evolutionary ecology. Male danaine butterflies are thought to utilize PAs as precursors for the production of dihydropyrrolizines [e.g. danaidone (DO) and hydroxydanaidal (HD)] in their two distinct androconial organs, viz. alar scent organs (sex brands) and abdominal hairpencils. However, little is known about the quantitative profiles of these compounds in danaines, the mechanism for their formation in the androconial organs, or their biological functions, particularly in mating behaviour. The present study addressed these unanswered questions posed for males of the danaine butterfly, Parantica sita. Chemical analyses of androconial extracts revealed considerable seasonal/regional and individual variations of the amounts of DO (the major dihydropyrrolizine produced) and 7R-HD (the 7R-enantiomer of HD detected in this study) found in the two organs. These variations seemed to depend primarily on the age of the male and the phenological traits of PA-containing plants available. Males were found to acquire an adequate capability to produce DO ~1 week after eclosion. DO was shown to be produced exclusively in the sex brand and subsequently physically transferred to the hairpencil through a contact behaviour between the two organs, here termed ‘perfuming behaviour’. The results of behavioural experiments with PA-fed and PA-unfed males that were allowed to compete for mates, combined with the positive electroantennographic (EAG) responses of the female, to both DO and 7R-HD, led to the conclusion that either or both of these compounds can act as the sex pheromone. Oral administration of PAs to males indicated that DO can be biosynthesized from various PA precursors, while 7R-HD, unlike in arctiid moths, is derived only from PAs with the 7R-configuration. The putative biosynthetic pathways of DO and 7R-HD, and the evolutionary provenance of the binate androconial system in the Danainae are also discussed.

Transmissible cancers in an evolutionary context.

Cancer is an evolutionary and ecological process in which complex interactions between tumour cells and their environment share many similarities with organismal evolution. Tumour cells with highest adaptive potential have a selective advantage over less fit cells. Naturally occurring transmissible cancers provide an ideal model system for investigating the evolutionary arms race between cancer cells and their surrounding micro-environment and macro-environment. However, the evolutionary landscapes in which contagious cancers reside have not been subjected to comprehensive investigation. Here, we provide a multifocal analysis of transmissible tumour progression and discuss the selection forces that shape it. We demonstrate that transmissible cancers adapt to both their micro-environment and macro-environment, and evolutionary theories applied to organisms are also relevant to these unique diseases. The three naturally occurring transmissible cancers, canine transmissible venereal tumour (CTVT) and Tasmanian devil facial tumour disease (DFTD) and the recently discovered clam leukaemia, exhibit different evolutionary phases: (i) CTVT, the oldest naturally occurring cell line is remarkably stable; (ii) DFTD exhibits the signs of stepwise cancer evolution; and (iii) clam leukaemia shows genetic instability. While all three contagious cancers carry the signature of ongoing and fairly recent adaptations to selective forces, CTVT appears to have reached an evolutionary stalemate with its host, while DFTD and the clam leukaemia appear to be still at a more dynamic phase of their evolution. Parallel investigation of contagious cancer genomes and transcriptomes and of their micro-environment and macro-environment could shed light on the selective forces shaping tumour development at different time points: during the progressive phase and at the endpoint. A greater understanding of transmissible cancers from an evolutionary ecology perspective will provide novel avenues for the prevention and treatment of both contagious and non-communicable cancers.

Explaining phenotypic and behavioural variability in Ochrogaster lunifer (Lepidoptera: Notodontidae) from an evolutionary ecology perspective

Explaining phenotypic and behavioural variability in Ochrogaster lunifer (Lepidoptera: Notodontidae) from an evolutionary ecology perspective

An evolutionary ecology perspective to address forest pathology challenges of today and tomorrow

Abstract Key message Increasing human impacts on forests, including unintentional movement of pathogens, climate change, and large-scale intensive plantations, are associated with an unprecedented rate of new diseases. An evolutionary ecology perspective can help address these challenges and provide direction for sustainable forest management. Context Forest pathology has historically relied on an ecological approach to understand and address the practical management of forest diseases. A widening of this perspective to include evolutionary considerations has been increasingly developed in response to the rising rates of genetic change in both pathogen populations and tree populations due to human activities. Aims Here, five topics for which the evolutionary perspective is especially relevant are highlighted. Results The first relates to the evolutionary diversity of fungi and fungal-like organisms, with issues linked to the identification of species and their ecological niches. The second theme deals with the evolutionary processes that allow forest pathogens to adapt to new hosts after introductions or to become more virulent in homogeneous plantations. The third theme presents issues linked to disease resistance in tree breeding programs (e.g., growth-defense trade-offs) and proposes new criteria and methods for more durable resistance. The last two themes are dedicated to the biotic environment of the tree–pathogen system, namely, hyperparasites and tree microbiota, as possible solutions for health management. Conclusion We conclude by highlighting three major conceptual advances brought by evolutionary biology, i.e., that (i) “not everything is everywhere”, (ii) evolution of pathogen populations can occur on short time scales, and (iii) the tree is a multitrophic community. We further translate these into a framework for immediate policy recommendations and future directions for research.

Frequency dependence 3.0: an attempt at codifying the evolutionary ecology perspective.

The fitness concept and perforce the definition of frequency independent fitnesses from population genetics is closely tied to discrete time population models with non-overlapping generations. Evolutionary ecologists generally focus on trait evolution through repeated mutant substitutions in populations with complicated life histories. This goes with using the per capita invasion speed of mutants as their fitness. In this paper we develop a concept of frequency independence that attempts to capture the practical use of the term by ecologists, which although inspired by population genetics rarely fits its strict definition. We propose to call the invasion fitnesses of an eco-evolutionary model frequency independent when the phenotypes can be ranked by competitive strength, measured by who can invade whom. This is equivalent to the absence of weak priority effects, protected dimorphisms and rock–scissor–paper configurations. Our concept differs from that of Heino et al. (TREE 13:367–370, 1998) in that it is based only on the signs of the invasion fitnesses, whereas Heino et al. based their definitions on the structure of the feedback environment, summarising the effect of all direct and indirect interactions between individuals on fitness. As it turns out, according to our new definition an eco-evolutionary model has frequency independent fitnesses if and only if the effect of the feedback environment on the fitness signs can be summarised by a single scalar with monotonic effect. This may be compared with Heino et al.’s concept of trivial frequency dependence defined by the environmental feedback influencing fitness, and not just its sign, in a scalar manner, without any monotonicity restriction. As it turns out, absence of the latter restriction leaves room for rock–scissor–paper configurations. Since in ‘realistic’ (as opposed to toy) models frequency independence is exceedingly rare, we also define a concept of weak frequency dependence, which can be interpreted intuitively as almost frequency independence, and analyse in which sense and to what extent the restrictions on the potential model outcomes of the frequency independent case stay intact for models with weak frequency dependence.

Patch Choice, Landscape Ecology, and Foraging Efficiency: the Zooarchaeology of Late Holocene Foragers in Western Argentina

Abstract Different but complementary foraging adaptations existed in the Payunia volcanic and the Andean highland (or mountain) subregions of southern Mendoza, Argentina during the late Holocene. We employ an evolutionary ecological perspective to study the zooarchaeology of foraging adaptations after 4000 BP. Seasonal exploitation of guanaco (Lama guanicoe Muller) in the mountains appears to have been sustainable, which relates to high productivity of mountain river valley bottoms during the late Holocene. The mountains were a productive, seasonally available resource patch. A greater diversity of fauna in the Payunia subregion resulted in a different foraging strategy with larger diet breadth. Despite mounting evidence that human population growth occurred during the late Holocene, there is little evidence of resource depression of high-ranked resources, such as the guanaco. Application of foraging theory models in this context clarifies that hunting decisions occurred in the context of two factors, str...

Defensive mixology: combining acquired chemicals towards defence

Summary The myriad chemicals produced by plants may act in combination to enhance chemical defence against herbivores. Many animals have evolved the ability to harness plant secondary metabolites (PSMs) and other chemical resources for their own defence, but few studies have addressed the compelling notion that non‐human animals combine exogenous chemicals from different sources to defend themselves against predators, parasites and pathogens. We consider the use of ‘defensive cocktails’ from an evolutionary ecology perspective, introducing the term, ‘acquired combinatorial chemical defence’ (ACCD). We define ACCD as the adaptive use of multiple chemicals of discrete origin resulting in defence against natural enemies. First, we discuss the defining characteristics of ACCD: the ability to harness interspecific chemical variation, to independently regulate it, and to obtain defensive benefits via synergy that exceed those associated with single sources. Then, we describe three non‐mutually exclusive modes by which acquired chemicals may operate against natural enemies: different chemical resources may provide defence during different stages of development, may be effective against different enemies or may work additively or synergistically against a given enemy at a given developmental stage. Next, we describe possible avenues by which chemical combinations may be acquired by herbivores and other taxa, including the mixing of exogenous chemicals from different items in the diet and mixing chemicals of dietary origin with those from non‐food resources. We discuss possible costs of ACCD, including detoxification costs and interactions with the immune system, and discuss methods of testing for ACCD and its costs. Finally, we discuss the evolutionary prediction that herbivores may converge on the use of complementary combinations of chemical resources from the environment or chemical defence syndromes. Opportunities to combine chemical resources abound, suggesting that animal and human medication may be more closely aligned than previously recognized.

Resilience of forests to pathogens: an evolutionary ecology perspective

Both natural and managed forests are currently suffering from increases in damage by pathogens. Here, an evolutionary ecology approach is adopted to analyse the factors that influence the levels of pathogen damage experienced by forest tree populations and consider the conditions under which stable co-existence of trees and pathogens occurs in natural populations. The demographic and genetic responses of tree–pathogen systems to anthropogenic perturbations are explored to identify where the greatest threats to resilience lie. Problems caused by native pathogens are likely to arise as a consequence both of rapid climate change and of forest management practices that lead to increases in species density, drastic reductions in genetic diversity and planting outside the native range. The most serious threats to forest trees are posed by introduction of exotic pathogens derived from related exotic tree species. Recovery following spread of exotic pathogens is likely to be both slow and uncertain and may not be possible without intensive programmes involving rapid selection and widespread dissemination of genotypes resistant to the exotic pathogen.

Modeling TGF-β in Early Stages of Cancer Tissue Dynamics

Recent works have highlighted a double role for the Transforming Growth Factor (-): it inhibits cancer in healthy cells and potentiates tumor progression during late stage of tumorigenicity, respectively; therefore it has been termed the “Jekyll and Hyde” of cancer or, alternatively, an “excellent servant but a bad master”. It remains unclear how this molecule could have the two opposite behaviours. In this work, we propose a - multi scale mathematical model at molecular, cellular and tissue scales. The multi scalar behaviours of the - are described by three coupled models built up together which can approximatively be related to distinct microscopic, mesoscopic, and macroscopic scales, respectively. We first model the dynamics of - at the single-cell level by taking into account the intracellular and extracellular balance and the autocrine and paracrine behaviour of -. Then we use the average estimates of the - from the first model to understand its dynamics in a model of duct breast tissue. Although the cellular model and the tissue model describe phenomena at different time scales, their cumulative dynamics explain the changes in the role of - in the progression from healthy to pre-tumoral to cancer. We estimate various parameters by using available gene expression datasets. Despite the fact that our model does not describe an explicit tissue geometry, it provides quantitative inference on the stage and progression of breast cancer tissue invasion that could be compared with epidemiological data in literature. Finally in the last model, we investigated the invasion of breast cancer cells in the bone niches and the subsequent disregulation of bone remodeling processes. The bone model provides an effective description of the bone dynamics in healthy and early stages cancer conditions and offers an evolutionary ecological perspective of the dynamics of the competition between cancer and healthy cells.

The Voice of Wisdom

To understand better how age-related physical qualities affect age stereotyping, this research investigated the social judgments young adult listeners make when they hear the voices of younger, middle-aged, and older adult speakers. Ninety-six listeners judged 24 speakers (22-79 years in age) reading a content-neutral passage. The listeners rated each speaker on scales reflecting character traits, vocal characteristics, and social affordances. Consistent with traditional age stereotypes, listeners judged older speakers to be less powerful and less engaged than younger speakers. However, even stronger than these negative impressions were positive impressions of older speakers’ greater wisdom, which were associated with distinct age-related vocal qualities. Moreover, although listeners indicated a desire to avoid interactions with older speakers, they acknowledged them as good storytellers. The positive impressions of older speakers are interpreted within an evolutionary-ecological perspective, suggesting that some age-related vocal qualities reveal long-standing, adaptive traits associated with older adulthood.

Correction: Coadaptation of Offspring Begging and Parental Provisioning - An Evolutionary Ecological Perspective on Avian Family Life

Correction: Coadaptation of Offspring Begging and Parental Provisioning - An Evolutionary Ecological Perspective on Avian Family Life

Coadaptation of Offspring Begging and Parental Provisioning - An Evolutionary Ecological Perspective on Avian Family Life

Offspring begging and parental provisioning are the two central social behaviours expressed during the period of parental care. Both behaviours influence each other and it is, therefore, hypothesized that they should ultimately become (genetically) correlated, stabilized by fitness costs to parents and/or offspring. By reciprocally exchanging entire clutches in canaries (Serinus canaria), we tested (1) whether there is covariation between these behaviours and (2) whether a mismatch - as introduced by cross-fostering - entails costs. Begging was scored in a standardized begging test and parental provisioning was measured via (a) the actual feeding rate and (b) using the growth rate of the foster nestlings as a proxy. Costs were established in terms of future reproductive investment in subsequent clutches and offspring growth. We found a positive and significant phenotypic covariation between offspring begging and parental feeding when using the growth rate as a proxy and, to a lesser extent, in case of the parental feeding rate. Female parents suffered no future reproductive costs when feeding foster nestlings that were more demanding than their own nestlings. Neither growth measured amongst all offspring nor the reproductive investment measured amongst the female offspring as adults was influenced by their begging behaviour. However, the reproductive investment of female offspring tended to depend on the parental qualities of their foster parents. Thus, offspring may only be able to extract resources within the limit of generosity of their foster parents. This suggests parental control of feeding, which is also supported by the positive covariation between offspring begging and parental feeding.

Embracing Thanatos-in-Eros: Evolutionary Ecology and Panentheism

If Panentheism’s core thesis, that God is in the world, is to animate a spiritual approach to life, then we have to account for the way in which God is in the destructive or thanative dimensions of life. From the perspective of evolutionary ecology the universe is imbued with creative and destructive energies. The creative drive can be termed eros as creation occurs through the expansion of relational unities, holons. The destructive drive is termed thanatos and is the drive to sever connection. An argument is developed from the perspective of evolutionary ecology to show how thanatos serves eros, serves the evolutionary unfolding of higher orders of communion. I suggest there are healthy and pathological expressions of the thanative drive. God within the thanative invites us to embrace the transformative potentials of suffering by integrating thanatos-in-eros. God as eros invites us to develop expanded modes of connection, inter-subjectivity and communion.

Darwinian interventions: taming pathogens through evolutionary ecology

From the seemingly inevitable emergence of antibiotic resistance following drug use to the necessity of annual influenza vaccine updates, the ability of pathogens to evolve appears to preclude the development of effective, long-term interventions for many diseases. Despite this gloomy forecast, recent research explores how various principles and concepts from evolutionary ecology might inform practical attempts to bring these disease-causing agents under greater human control. By utilizing evolutionary and ecological information at various scales, these works investigate some promising avenues of disease intervention, from trapping pathogens in evolutionary dead ends, through slowing or inhibiting the process of pathogen adaptation, to more accurate forecasting of pathogen evolutionary trajectories. Thus, an evolutionary ecology perspective might ultimately provide powerful new tools in the pursuit of enduring solutions to the problem of treatment-driven pathogen evolution.