Content uploaded by Gloria Massamba N’Siala
Author content
All content in this area was uploaded by Gloria Massamba N’Siala on Dec 02, 2014
Content may be subject to copyright.
A preview of the PDF is not available
Trans-generational plasticity in physiological thermal tolerance is modulated by maternal pre-reproductive environment in the polychaete Ophryotrocha labronica
Abstract and Figures
Maternal temperature is known to affect many aspects of offspring phenotype, but its effect on offspring physiological thermal tolerance has received less attention, despite the importance of physiological traits in defining organismal ability to cope with temperature changes. To fill this gap, we used the marine polychaete, Ophryotrocha labronica, to investigate the influence of maternal temperature on offspring upper and lower thermal tolerance limits, and assess whether maternal influence changed according to the stage of offspring pre-zygotic development at which a thermal cue was provided. Measurements were taken on adult offspring acclimated to 18°C or 30°C, produced by mothers previously reared at 24°C and then exposed to 18°C or 30°C at an early and late stage of oogenesis. When the shift from 24°C was provided early during oogenesis, mothers produced offspring with greater cold and heat tolerance whenever mother-offspring temperatures did not match, respect to when they matched, suggesting the presence of an anticipatory maternal effect triggered by the thermal variation. Conversely, when the cue was provided later during oogenesis, more tolerant offspring were observed when temperatures persisted across generations. In this case, maternal exposure to 18°C or 30°C may have benefited offspring performance, while limitations in the transmission of the thermal cue may account for the lack of correlation between maternal experiences and offspring performance when mother-offspring environments did not match. Our results provided evidence for a trans-generational effect of temperature on physiological performance characterised by a high context-dependency, and were discussed in the light of maternal pre-reproductive experiences.
Figures - uploaded by Gloria Massamba N’Siala
Author content
All figure content in this area was uploaded by Gloria Massamba N’Siala
Content may be subject to copyright.
... Organisms can have different responses to warmer temperatures: diffuse towards more favourable habitats, cope with new conditions through phenotypic and physiological plasticity (Fox et al., 2019), or adapt through genetic changes (Hofmann 2005;Gibbin et al., 2017). Regarding thermal acclimation, phenotypic plasticity can be any phenotypic alteration (usually reversible) in physiology promoted by environmental temperature that modifies organisms' performance, possibly improving their fitness (Chown et al., 2009;Massamba-N'Siala et al., 2014). On the opposite, some phenotypic plasticity responses are non-reversible and remain throughout the organism's life cycle, leading to carry over effects that determine fitness outcomes (Slotsbo et al., 2016;Moore and Martin 2019). ...
... Accordingly, phenotypic plasticity in physiological and life-history traits, occurring within-and trans-generationally, is known to buffer the negative effects of climate change (Gibbin et al., 2017). If adaptive, it allows species to persist in a specific habitat/environment by having a positive effect on fitness (Reed et al., 2011;Grenier et al., 2016;Bonamour et al., 2019) Thus, as suggested by Massamba-N'Siala et al. (2014) and Chakravarti et al. (2016), this improved response capacity may facilitate the ability of populations and species to cope with the challenges raised by climate change within and across generations. However, phenotypic plasticity is a trait that is subject to evolutionary change itself (Gibbin et al., 2017). ...
Global projections predict significant increases in ocean temperature and changes in ocean chemistry, including salinity variations by 2100. This has led to a substantial interest in the study of thermal ecophysiology, as temperature is a major factor shaping marine ectotherm communities. However, responses to temperature may be influenced by other factors such as salinity, highlighting the relevance of multiple stressor studies. In the present work, we experimentally evaluated the thermal tolerance of the marine ragworm Hediste diversicolor under predicted global change scenarios. Organisms were subjected to an experimental trial under control (24 °C), and two temperature treatment scenarios (ocean warming +3 °C - (27 °C) and heat wave +6 °C - (30 °C)), combined with salinity variations (20 and 30) in a full factorial design for 29 days. Environmental data from the field were collected during 2019 and 2020. At day 30 post exposure, upper thermal limits (Critical Thermal Maximum - CTMax), thermal safety margins (TSM) and acclimation capacity were measured. Higher acclimation temperatures led to higher thermal tolerance limits, confirming that H. diversicolor features some physiological plasticity, acclimation capacity and a positive thermal safety margin. This margin was greater considering in situ temperature data from 2019 than maximum temperatures for 2020 (CTMax > maximum habitat temperature-MHT). Moreover, smaller organisms displayed higher upper thermal limits suggesting that thermal tolerance is size dependent. Ragworms subjected to higher salinity also showed a higher CTMax than those acclimated to lower salinity. However, temperature and salinity showed an additive effect on CTMax, as no significant interaction was detected. We conclude that H. diversicolor can easily acclimate to increased water temperature, independently of salinity variations. Given the key role of ragworms in food webs in estuaries and coastal lagoons, substrate bioturbation and aquaculture, this information is relevant to support conservation actions, optimize culture protocols and identify thermal resistant strains.
... These results join other studies that examined TGP in marine invertebrates in response to thermal stress, where the offspring response varied with species, timing, and nature of parental conditioning (Putnam and Gates, 2015;Shama, 2015;Morley et al., 2017;Rivera et al., 2021;Bernal et al., 2022;Waite and Sorte, 2022). For example, in a study on the marine polychaetae, Ophryotrocha labronica, researchers found that the thermal tolerance of the progeny tracked the timing of the temperature exposure of the female, where tolerance of offspring differed depending on whether maternal acclimation occurred during early or late oogenesis (Massamba-N'Siala et al., 2014). These results match the outcome of our experiment in S. purpuratus. ...
Kelp forests of the California Current System have experienced prolonged marine heatwave (MHW) events that overlap in time with the phenology of life history events (e.g., gametogenesis and spawning) of many benthic marine invertebrates. To study the effect of thermal stress from MHWs during gametogenesis in the purple sea urchin (Strongylocentrotus purpuratus) and further, whether MHWs might induce transgenerational plasticity (TGP) in thermal tolerance of progeny, adult urchins were acclimated to two conditions in the laboratory – a MHW temperature of 18°C and a non-MHW temperature of 13°C. Following a four-month long acclimation period (October–January), adults were spawned and offspring from each parental condition were reared at MHW (18°C) and non-MHW temperatures (13°C), creating a total of four embryo treatment groups. To assess transgenerational effects for each of the four groups, we measured thermal tolerance of hatched blastula embryos in acute thermal tolerance trials. Embryos from MHW-acclimated females were more thermally tolerant with higher LT50 values as compared to progeny from non-MHW-acclimated females. Additionally, there was an effect of female acclimation state on offspring body size at two stages of embryonic development - early gastrulae and prism, an early stage echinopluteus larvae. To assess maternal provisioning as means to also alter embryo performance, we assessed gamete traits from the differentially acclimated females, by measuring size and biochemical composition of eggs. MHW-acclimated females had eggs with higher protein concentrations, while egg size and lipid content showed no differences. Our results indicate that TGP plays a role in altering the performance of progeny as a function of the thermal history of the female, especially when thermal stress coincides with gametogenesis. In addition, the data on egg provisioning show that maternal experience can influence embryo traits via egg protein content. Although this is a laboratory-based study, the results suggest that TGP may play a role in the resistance and tolerance of S. purpuratus early stages in the natural kelp forest setting.
... Central to the ability to remain and endure the challenges associated with temperate winters is the capacity to respond to environmental cues such as shortening day lengths and declining temperatures to trigger seasonal cold adaptation (Teets & Denlinger, 2013). Such seasonal adaptation is incurred via adaptive phenotypic plasticity and may encompass short-term changes to the physiology or behavior of the individual that act to enhance thermotolerance (May, 1979;Overgaard & MacMillan, 2017), to longer-term transgenerational plasticity (Massamba-N'Siala et al., 2014;Walsh et al., 2014). In ectothermic organisms, physiological changes to enhance thermotolerance may include changes to homeostatic balance, lipid membrane composition, cryoprotective osmolytes, and heat shock protein expression (Overgaard & MacMillan, 2017). ...
Physiological thermotolerance and behavioral thermoregulation are central to seasonal cold adaptation in ectothermic organisms. For species with enhanced mobility, behavioral responses may be of greater importance in the cold stress response. Employing the carabid beetles as a study organism, the current study compared physiological thermotolerance and behavioral thermoregulation in carabid species inhabiting cereal fields in different landscape contexts, from fine grain heterogeneous ‘complex’ landscapes to homogenous ‘simple’ landscapes. Physiological thermotolerance was determined via measurement of the CTmin and chill coma temperature. Behavioral responses to cold temperature exposure were determined employing a purpose built arena, and thoracic temperature measured to estimate the efficacy of the behavior as a form of behavioral thermoregulation. Results revealed an influence of landscape composition on the cold tolerance of carabid beetles, although species differed in their sensitivity to landscape intensification. A reduced effect of landscape on the thermotolerance of larger carabid beetles was observed, thought to be the consequence of greater mobility preventing local acclimation to microclimatic variation along the landscape intensification gradient. Investigation into behavioral thermoregulation of the three largest species revealed burrowing behavior to be the main behavioral response to cold stress, acting to significantly raise carabid body temperature. This finding highlights the importance of behavioral thermoregulation as a strategy to evade cold stress. The use of behavioral thermoregulation may negate the need to invest in physiological thermotolerance, further offering explanation for the lack of landscape effect on the physiological thermotolerance of larger carabids. This article is protected by copyright. All rights reserved
... The conditions experienced by parents can shape the performance of offspring via non-genetic maternal effects (or 'parental effects' for effects of a more general class) (Bernado, 1996;Marshall and Keogh, 2008) and/or epigenetic processes . This ability, referred to as transgenerational acclimation or plasticity, can act as a key strategy to optimize individual fitness in fluctuating environments (Massamba-N'Siala et al., 2014) and an important mechanism for coping with rapid environmental variations across generations (Salinas and Munch, 2012;Donelson et al., 2018). In animal and plant ecology, the terms 'transgenerational plasticity' (TGP) as well as 'parental' and/or 'maternal effects' are usually reserved for sexual reproduction (Latzel and Klimešová, 2010). ...
Jellyfish population cycles and bloom events occur at global, regional, and local scales. Understanding what causes these cycles now and in the future is a major question in jellyfish bloom research, because of the potential impacts on ecosystem function and services. Most bloom forming scyphozoan jellyfish have complex life histories involving a long-lived asexually reproducing benthic polyp and a sexually reproducing pelagic medusae. Environmental and climate factors affect each life stage, but we do not fully understand how these variables drive life stage transition, or how demographic differences in survival, growth and fecundity translate into visible jellyfish outbreaks. We undertook a comprehensive laboratory and field-based study of the physicochemical conditions that control survival, fecundity and phase transition of the different life stages of scyphozoan jellyfish. Through this research, we examine the effects of environmental drivers on jellyfish population cycles and life stage transition. Modifications to estuaries through the construction of barrages alter the natural dynamics of inhabitant species by controlling freshwater inputs into those systems, driving the presence and absence of medusae from estuaries. As well as this, we explore how environmental conditions translate into reproductive success or failure in temperate populations from the medusa to the polyp life stage, demonstrating that early polyp growth rates are strongly linked to their thermal environment and highlighting a potential marine heatwave event. We examine not only the effects of temperature and other climate drivers on scyphozoan jellyfish growth, survival and reproduction, but also whether epigenetic transgenerational effects can drive acclimation to warmer summer temperatures in the short term in the context of a warming ocean. No parental effects were observed in the first or second generation, and in the third generation the transgenerational effects of temperature were subtle and appeared most strongly in cooling scenarios. Finally, within the setting of anthropogenically-driven climate change, we demonstrate for the first time that A. aurita polyps require a minimum period of cooler temperatures to strobilate, contradicting claims that jellyfish populations will be more prevalent in warming oceans, specifically in the context of warmer winter conditions. To answer these questions, we chose the common, or moon jellyfish Aurelia aurita as our primary experimental organism. However, we expanded our research to other species to demonstrate how they may vary in both environment and response to forcing factors as compared to a ‘typical’ model species. This thesis highlights the importance of examining each population within the context of their environment, and advances our understanding of how the climate and environment affect jellyfish life stage transition.
Trans-generational immune priming (TGIP) adjusts offspring immune responses based on parental immunological experiences - a form of trans-generational plasticity predicted to be adaptive when parent-offspring environmental conditions match. In contrast, mis-matches between environmental conditions negate those advantages, rendering TGIP costly when mismatched immunological offspring phenotypes are induced. Particularly maternal TGIP was thought to shape offspring immunological preparedness: mothers' eggs contain more substance than sperm and, in viviparous species, pregnancy provides additional avenues for immune priming of developing offspring. The syngnathids' (pipefishes and seahorses) unique male pregnancy provides an unusual perspective to the ecological relevance of TGIP in a system where egg production and pregnancy occur in different sexes. We simulated parental bacteria exposure in broad nosed pipefish, Syngnathus typhle, through vaccinations with heat-killed Vibrio aestuarianus before mating the fish to each other or control individuals. Resulting offspring were raised, and some exposed to V. aestuarianus, in a control or heat-stress environment, after which transcriptome and microbiome compositions were investigated. Transcriptomic TGIP effects were only observed in Vibrio-exposed offspring at control temperatures, arguing for low costs of TGIP in non-matching environments. Transcriptomic phenotypes elicited by maternal and paternal TGIP had only limited overlap and were not additive. Both transcriptomic responses were significantly associated to immune functions, and specifically the paternal response to the innate immune branch. TGIP of both parents reduced the relative abundance of the experimental Vibrio in exposed offspring, showcasing its ecological effectiveness. Despite its significance in matching biotic environments, no TGIP-associated phenotypes were observed for heat-treated offspring. Heat-spikes caused by climate change thus threaten TGIP benefits, potentially increasing susceptibility to emerging marine diseases. This highlights the urgent need to understand how animals will cope with climate-induced changes in microbial assemblages by illustrating the importance - and limits - of TGIP in mitigating the impacts of environmental stressors on offspring vulnerability.
Species interactions are expected to change in myriad ways as the frequency and magnitude of extreme temperature events increase with anthropogenic climate change.
The relationships between endosymbionts, parasites and their hosts are particularly sensitive to thermal stress, which can have cascading effects on other trophic levels.
We investigate the interactive effects of heat stress and parasitism on a terrestrial tritrophic system consisting of two host plants (one common, high‐quality plant and one novel, low‐quality plant), a caterpillar herbivore and a specialist parasitoid wasp.
We used a fully factorial experiment to determine the bottom‐up effects of the novel host plant on both the caterpillars' life history traits and the wasps' survival, and the top‐down effects of parasitism and heat shock on caterpillar developmental outcomes and herbivory levels.
Host plant identity interacted with thermal stress to affect wasp success, with wasps performing better on the low‐quality host plant under constant temperatures but worse under heat‐shock conditions.
Surprisingly, caterpillars consumed less leaf material from the low‐quality host plant to reach the same final mass across developmental outcomes.
In parasitized caterpillars, heat shock reduced parasitoid survival and increased both caterpillar final mass and development time on both host plants.
These findings highlight the importance of studying community‐level responses to climate change from a holistic and integrative perspective and provide insight into potential substantial interactions between thermal stress and diet quality in plant–insect systems.
Read the free Plain Language Summary for this article on the Journal blog.
High temperatures alter the physiological condition of Octopus maya embryos, juveniles, and adults, and the time of exposure could have a key role in their thermal tolerance. The present study evaluates the effects of temperature and exposure time on octopus juveniles obtained from thermal-stressed and non-stressed females when exposed to optimal (25°C) and high temperatures (30°C) for 20 and 30 days, respectively. The results showed a transgenerational temperature effect that was expressed with low survival, depressed routine resting and high metabolic rates. Moreover, a collapse of antioxidant defense enzymes and high radical oxygen species (ROS) levels were detected in juveniles from thermally stressed females. Stress was lethal for animals acclimated at 30°C, while the performance of juveniles acclimated at optimal temperature (25°C) was conditioned by high ROS and low high metabolic rate (HMR) levels even after 30 days of experiment. In contrast, juveniles from non-thermally stressed females had an optimal performance when acclimated at 25°C but at 30°C, they had a comparatively higher HMR during the first eight days. These results suggest energy surplus in those animals to escape from warming scenarios before experiencing ROS accumulation. Further studies should confirm if epigenetic alterations could be involved.
Among ectotherms, rare species are expected to have a narrower thermal niche breadth and reduced acclimation capacity and thus be more vulnerable to global warming than their common relatives. To assess these hypotheses, we experimentally quantified the thermal sensitivity of seven common, uncommon, and rare species of temperate marine annelids of the genus Ophryotrocha to assess their vulnerability to ocean warming. We measured the upper and lower limits of physiological thermal tolerance, survival, and reproductive performance of each species along a temperature gradient (18, 24, and 30 °C). We then combined this information to produce curves of each species’ fundamental thermal niche by including trait plasticity. Each thermal curve was then expressed as a habitat suitability index (HSI) and projected for the Mediterranean Sea and temperate Atlantic Ocean under a present day (1970–2000), mid- (2050–2059) and late- (2090–2099) 21st Century scenario for two climate change scenarios (RCP2.6 and RCP8.5). Rare and uncommon species showed a reduced upper thermal tolerance compared to common species, and the niche breadth and acclimation capacity were comparable among groups. The simulations predicted an overall increase in the HSI for all species and identified potential hotspots of HSI decline for uncommon and rare species along the warm boundaries of their potential distribution, though they failed to project the higher sensitivity of these species into a greater vulnerability to ocean warming. In the discussion, we provide some caveats on the implications of our results for conservation efforts.
Among ectotherms, rare species are expected to have a narrower thermal niche breadth and reduced acclimation capacity and thus be more vulnerable to global warming than their common relatives. To assess these hypotheses, we experimentally quantified the thermal sensitivity of seven common, uncommon, and rare species of temperate marine annelids of the genus Ophryotrocha to assess those species’ vulnerability to ocean warming. We measured the upper and lower limits of physiological thermal tolerance, survival, and reproductive performance of each species along a temperature gradient (18, 24, and 30°C). We then combined this information to produce curves of each species’ fundamental thermal niche by including trait plasticity. Each thermal curve was then expressed as a habitat suitability index (HSI) and projected for the Mediterranean Sea and temperate Atlantic Ocean under a present day (1970-2000), mid- (2050-2059) and late- (2090-2099) 21st Century scenario for two climate change scenarios (RCP2.6 and RCP8.5). Rare and uncommon species showed a reduced upper thermal tolerance compared to common species, and the niche breadth and acclimation capacity were comparable among groups. The simulations predicted an overall increase in the HSI for all species and identified potential hotspots of HSI decline for uncommon and rare species along the warm boundaries of their potential distribution, though they failed to project the higher sensitivity of these species into a greater vulnerability to ocean warming. In the discussion, we provide elements and caveats on the implications of our results for conservation efforts.
Phenotypic plasticity in parental care investment allows organisms to promptly respond to rapid environmental changes by potentially benefiting offspring survival and thus parental fitness. To date, a knowledge gap exists on whether plasticity in parental care behaviors can mediate responses to climate change in marine ectotherms. Here, we assessed the plasticity of parental care investment under elevated temperatures in a gonochoric marine annelid with biparental care, Ophryotrocha labronica, and investigated its role in maintaining the reproductive success of this species in a warming ocean. We measured the time individuals spent carrying out parental care activities across three phases of embryonic development, as well as the hatching success of the offspring as a proxy for reproductive success, at control (24℃) and elevated (27℃) temperature conditions. Under elevated temperature, we observed: (a) a significant decrease in total parental care activity, underpinned by a decreased in male and simultaneous parental care activity, in the late stage of embryonic development; and (b) a reduction in hatching success that was however not significantly related to changes in parental care activity levels. These findings, along with the observed unaltered somatic growth of parents and decreased brood size, suggest that potential cost-benefit trade-offs between offspring survival (i.e., immediate fitness) and parents' somatic condition (i.e., longer-term fitness potential) may occur under ongoing ocean warming. Finally, our results suggest that plasticity in parental care behavior is a mechanism able to partially mitigate the negative effects of temperature-dependent impacts.
Phenotypic plasticity is the range and process of variation in body plan and physiology. This book pulls together recent theoretical advances in phenotypic plasticity, as influenced by evolution and development. The editors and the chapter authors are among the leaders of this exciting and active subfield. The volume begins with a primer on the basic principles of the subject, and companion chapters on phenotypic plasticity in plants and animals. Of interest to a wide range of researchers on evolution, development, and their interface.
Biologists working in fields as diverse as mammalian behavior, plant ecology, microbial genetics, quantitative genetics, and insect ecology have shown that environmentally induced parental effects can be found in most kingdoms of living organisms. Such effects are diverse, have multiple causes, and can be transmitted via multiple pathways. Historically, and understandably, these effects have been studied by biologists who have focused on a particular group of organisms, such as insects or plants, or who have approached the phenomenon from a particular point of view, such as quantitative genetics, ecology, or behavior. The consequence has been the development of multiple terminologies that are not used consistently across disciplines or kingdoms. I believe these inconsistencies hinder the communication among biologists studying these effects, the development of generalized models of parental effects, and the empirical testing of adaptedness of these effects.
Maternal effects occur when the phenotype of an individual is determined not only by its own genotype and the environmental conditions it experiences during development, but also by the phenotype or environment of its mother (Kempthorne 1969; Wright 1969; Falconer 1989). Indeed, in many species, the mother’s phenotype is the most important environmental condition experienced by an individual during development. The mother’s phenotype determines when and where an offspring is produced as well as the offspring’s size and quality, and in some instances the offspring’s sex (Trivers and Willard 1973; Janzen 1993). By clustering or dispersing offspring, the maternal phenotype has effects on offspring density, the postnatal competitive environment, and the vulnerability of the offspring to predators and disease. Maternal behaviors determine in many species whether and how density regulation occurs at the level of the family and the intensity of postnatal competition among the offspring for limited maternal resources.
Mothers have the ability to profoundly affect the quality of their offspring from the size and quality of their eggs to where, when, and how eggs and young are placed, and from providing for and protecting developing young to choosing a mate. In many instances, these maternal effects may be the single most important contributor to variation in offspring fitness. This book explores the wide variety of maternal effects that have evolved in plants and animals as mechanisms of adaptation to temporally and spatially heterogeneous environments. Topics range from the evolutionary implications of maternal effects to the assessment and measurement of maternal effects. Four detailed case studies are also included. This book represents the first synthesis of the current state of knowledge concerning the evolution of maternal effects and their adaptive significance.
Maternal effects can be defined as the cross generational transmission of individual quality such that the offspring survival, growth, and fecundity are affected by the properties of the environment in which the parents lived. Individual quality may have an uneven distribution in a population, but only the transmission of the average population quality will be discussed here since this chapter examines its influence on population dynamics. Recent reviews have shown the ecological and evolutionary importance of maternal effects in insects (Mousseau and Dingle 1991), plants (Roach and Wulf 1987), and mammals (Bernardo 1996, and references therein). Maternal effects induce a time lag in the reaction of populations to environmental changes. An environmental change may cause, for instance, a decrease in abundance. This would create better conditions for the average mother since there are less of them. Maternal quality passed to daughters (maternal effect) would therefore influence the rate of reproduction in the daughter’s generation. This time lag of exactly one generation creates the need to reflect the delayed effect of the previous generation’s environment on the current generation (Rossiter 1996). An approach to accounting for this effect is to introduce the concept of inertia into the population dynamics models. The inertial view of population dynamics based on maternal effects and its application to cycling populations is the subject of this chapter.
In Drosophila, field heritability estimates have focused on morphological traits and ignored maternal effects. This study considers heritable variation and maternal effects in a physiological trait, heat resistance. Drosophila were collected from the field in Melbourne, Australia. Resistance was determined using knock-down time at 37 degrees. Drosophila melanogaster was more resistant than Drosophila simulans, and males tended to be more resistant than females. Field heritability and maternal effects were examined in D. simulans using the regression of laboratory-reared F1 and F2 onto field-collected parents. Males from the field were crossed to a laboratory stock to obtain progeny. The additive genetic component to variation in heat resistance was large and significant, and heritability was estimated to be around 0.5. A large maternal effect was also evident. Comparisons of regression coefficients suggested that the maternal effect was not associated with cytoplasmic factors. There was no correlation between body size (as measured by wing length) and heat resistance. Unlike in the case of morphological traits, the heritability for heat resistance in nature is not less than that measured in the laboratory.
The first comprehensive synthesis on development and evolution: it applies to all aspects of development, at all levels of organization and in all organisms, taking advantage of modern findings on behavior, genetics, endocrinology, molecular biology, evolutionary theory and phylogenetics to show the connections between developmental mechanisms and evolutionary change. This book solves key problems that have impeded a definitive synthesis in the past. It uses new concepts and specific examples to show how to relate environmentally sensitive development to the genetic theory of adaptive evolution and to explain major patterns of change. In this book development includes not only embryology and the ontogeny of morphology, sometimes portrayed inadequately as governed by "regulatory genes," but also behavioral development and physiological adaptation, where plasticity is mediated by genetically complex mechanisms like hormones and learning. The book shows how the universal qualities of phenotypes--modular organization and plasticity--facilitate both integration and change. Here you will learn why it is wrong to describe organisms as genetically programmed; why environmental induction is likely to be more important in evolution than random mutation; and why it is crucial to consider both selection and developmental mechanism in explanations of adaptive evolution. This book satisfies the need for a truly general book on development, plasticity and evolution that applies to living organisms in all of their life stages and environments. Using an immense compendium of examples on many kinds of organisms, from viruses and bacteria to higher plants and animals, it shows how the phenotype is reorganized during evolution to produce novelties, and how alternative phenotypes occupy a pivotal role as a phase of evolution that fosters diversification and speeds change. The arguments of this book call for a new view of the major themes of evolutionary biology, as shown in chapters on gradualism, homology, environmental induction, speciation, radiation, macroevolution, punctuation, and the maintenance of sex. No other treatment of development and evolution since Darwin's offers such a comprehensive and critical discussion of the relevant issues. Developmental Plasticity and Evolution is designed for biologists interested in the development and evolution of behavior, life-history patterns, ecology, physiology, morphology and speciation. It will also appeal to evolutionary paleontologists, anthropologists, psychologists, and teachers of general biology.
