scholarly journals Developmental palaeontology in synapsids: the fossil record of ontogeny in mammals and their closest relatives

2010 ◽  
Vol 277 (1685) ◽  
pp. 1139-1147 ◽  
Author(s):  
Marcelo R. Sánchez-Villagra
Keyword(s):  
Life History ◽  
Developmental Plasticity ◽  
Ecological Factors ◽  
Evolutionary Mechanisms ◽  
Allometric Relations ◽  
Living Species ◽  
New Space ◽  
Absolute Age ◽  
Growth Features ◽  
Indirect Information

The study of fossilized ontogenies in mammals is mostly restricted to postnatal and late stages of growth, but nevertheless can deliver great insights into life history and evolutionary mechanisms affecting all aspects of development. Fossils provide evidence of developmental plasticity determined by ecological factors, as when allometric relations are modified in species which invaded a new space with a very different selection regime. This is the case of dwarfing and gigantism evolution in islands. Skeletochronological studies are restricted to the examination of growth marks mostly in the cement and dentine of teeth and can provide absolute age estimates. These, together with dental replacement data considered in a phylogenetic context, provide life-history information such as maturation time and longevity. Palaeohistology and dental replacement data document the more or less gradual but also convergent evolution of mammalian growth features during early synapsid evolution. Adult phenotypes of extinct mammals can inform developmental processes by showing a combination of features or levels of integration unrecorded in living species. Some adult features such as vertebral number, easily recorded in fossils, provide indirect information about somitogenesis and hox-gene expression boundaries. Developmental palaeontology is relevant for the discourse of ecological developmental biology, an area of research where features of growth and variation are fundamental and accessible among fossil mammals.

Hormones and Behavior

2019 ◽  
pp. 11-26
Author(s):  
Maren N. Vitousek ◽  
Laura A. Schoenle
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Traits ◽  
Developmental Plasticity ◽  
Endocrine System ◽  
Phenotypic Traits ◽  
Social Environments ◽  
Trade Offs ◽  
And Behavior

Hormones mediate the expression of life history traits—phenotypic traits that contribute to lifetime fitness (i.e., reproductive timing, growth rate, number and size of offspring). The endocrine system shapes phenotype by organizing tissues during developmental periods and by activating changes in behavior, physiology, and morphology in response to varying physical and social environments. Because hormones can simultaneously regulate many traits (hormonal pleiotropy), they are important mediators of life history trade-offs among growth, reproduction, and survival. This chapter reviews the role of hormones in shaping life histories with an emphasis on developmental plasticity and reversible flexibility in endocrine and life history traits. It also discusses the advantages of studying hormone–behavior interactions from an evolutionary perspective. Recent research in evolutionary endocrinology has provided insight into the heritability of endocrine traits, how selection on hormone systems may influence the evolution of life histories, and the role of hormonal pleiotropy in driving or constraining evolution.

Should I stay or should I go? Complex environments influence the developmental plasticity of flight capacity and flight-related trade-offs

2019 ◽  
Vol 128 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Jordan R Glass ◽  
Zachary R Stahlschmidt
Keyword(s):  
Life History ◽  
Food Availability ◽  
Life History Traits ◽  
Developmental Plasticity ◽  
Temperature Variability ◽  
Field Cricket ◽  
Valuable Insight ◽  
Complex Environments ◽  
Trade Offs ◽  
Flight Capacity

Abstract Complex environments, characterized by co-varying factors (e.g. temperature and food availability) may cause animals to invest resources differentially into fitness-related traits. Thus, experiments manipulating multiple environmental factors concurrently provide valuable insight into the role of the environment in shaping not only important traits (e.g. dispersal capacity or reproduction), but also trait–trait interactions (e.g. trade-offs between traits). We used a multi-factorial design to manipulate variation in temperature (constant 28 °C vs. 28 ± 5 °C daily cycle) and food availability (unlimited vs. intermittent access) throughout development in the sand field cricket (Gryllus firmus). Using a univariate approach, we found that temperature variability and unlimited food availability promoted survival, development, growth, body size and/or reproductive investment. Using principal components as indices of resource allocation strategy, we found that temperature variability and unlimited food reduced investment into flight capacity in females. Thus, we detected a sex-specific trade-off between flight and other life-history traits that was developmentally plastic in response to variation in temperature and food availability. We develop an experimental and statistical framework to reveal shifts in correlative patterns of investment into different life-history traits. This approach can be applied to a range of biological systems to investigate how environmental complexity influences traits and trait trade-offs.

Brain size evolution in anurans: a review

2019 ◽  
Vol 69 (3) ◽  
pp. 265-279 ◽  
Author(s):  
Chun Lan Mai ◽  
Wen Bo Liao
Keyword(s):  
Sexual Selection ◽  
Life History ◽  
Life History Traits ◽  
Developmental Stages ◽  
Brain Size ◽  
Ecological Factors ◽  
Brain Regions ◽  
Sperm Length ◽  
Testis Size ◽  
Size Evolution

Abstract Selection pressure is an important force in shaping the evolution of vertebrate brain size among populations within species as well as between species. The evolution of brain size is tightly linked to natural and sexual selection, and life-history traits. In particular, increased environmental stress, intensity of sexual selection, and slower life history usually result in enlarged brains. However, although previous studies have addressed the causes of brain size evolution, no systematic reviews have been conducted to explain brain size in anurans. Here, we review whether brain size evolution supports the cognitive buffer hypothesis (CBH), the expensive tissue hypothesis (ETH), or the developmental cost hypothesis (DCH) by analyzing the intraspecific and/or interspecific patterns in brain size and brain regions (i.e., olfactory nerves, olfactory bulbs, telencephalon, optic tectum, and cerebellum) associated with ecological factors (habitat, diet and predator risk), sexual selection intensity, life-history traits (age at sexual maturity, mean age, longevity, clutch size and egg size, testis size and sperm length), and other energetic organs. Our findings suggest that brain size evolution in anurans supports the CBH, ETH or DCH. We also suggest future directions for studying the relationships between brain size evolution and crypsis (i.e., ordinary mucous glands in the skin), and food alteration in different developmental stages.

scholarly journals Distributional range, ecology, and mating system of the Cape mole-rat (Georychus capensis) family Bathyergidae

2017 ◽  
Vol 95 (10) ◽  
pp. 713-726 ◽  
Author(s):  
J.H. Visser ◽  
N.C. Bennett ◽  
B. Jansen van Vuuren
Keyword(s):  
Life History ◽  
Mating System ◽  
Vegetation Type ◽  
Ecological Factors ◽  
Disjunct Distribution ◽  
Testis Size ◽  
Extrinsic Factors ◽  
Mole Rat ◽  
Testicular Size ◽  
Life History Patterns

Interpopulation variation in life-history patterns are influenced by intrinsic and extrinsic factors. Life-history patterns have been intensely studied in the eusocial African bathyergid species, largely neglecting the solitary species. Of these solitary genera, the Cape mole-rat (Georychus capensis (Pallas, 1778)) is endemic to South Africa with a disjunct distribution across its range. Knowledge regarding this species is rudimentary; therefore, this study aimed to investigate the current distribution of the species with particular attention to common ecological variables, differences in body size between localities and sexes, as well as its reproduction and mating system. Georychus is a habitat specialist restricted to specific ecological areas. A lack of sexual size dimorphism and correlation between male testis size and number of females in the population, suggests a polygynous mating system, facilitated by the spatial distribution of the sexes. A positive relationship between male testes size and percentage of females in populations sampled suggests that larger sperm reserves (i.e., larger testes) are required in populations with a higher percentage of females. In addition, mating variables (testicular size and litter size) are linked to ecological factors (elevation, aridity, soil type, and vegetation type) that could impact mate searching, mating success, and food resources.

scholarly journals Morphological plasticity reduces the effect of poor developmental conditions on fledging age in mourning doves

2010 ◽  
Vol 277 (1688) ◽  
pp. 1659-1665 ◽  
Author(s):  
David A. Miller
Keyword(s):  
Life History ◽  
Brood Size ◽  
Developmental Plasticity ◽  
Morphological Plasticity ◽  
Developmental Time ◽  
Body Parts ◽  
Structural Growth ◽  
Mourning Doves ◽  
Wing Growth ◽  
Developmental Conditions

Developmental plasticity can be integral in adapting organisms to the environment experienced during growth. Adaptive plastic responses may be especially important in prioritizing development in response to stress during ontogeny. To evaluate this, I examined how developmental conditions for mourning doves related to early growth and how this affected fledging age, an important life-history transition for birds. The life history of mourning doves is consistent with strong selective pressure to minimize fledging age. Therefore, I predicted that in the face of nutritional stress associated with experimental brood-size increases, young would prioritize growth to structures that promote early fledging to reduce the effect of slowed overall growth on fledging age. Increasing brood size slowed overall structural growth of nestlings and affected the relative allocation of growth among different body parts. Total wing area was the best predictor of fledging age and individuals from larger broods had larger wings relative to overall body size. Although nestlings from larger broods fledged at later ages owing to slower overall growth, prioritization of wing growth reduced this effect by an estimated 1.6 days relative to the delay if plasticity among body parts had not occurred. This was an 11 per cent reduction in the predicted developmental time it took to reach this important life-history transition. Results demonstrate that preferential allocation to wing growth can affect the timing of this life-history transition and that morphological plasticity during development can have adaptive near-term effects during avian development.

Are characteristics of introduced salmonid fishes biased by propagule pressure?

2005 ◽  
Vol 62 (4) ◽  
pp. 950-959 ◽  
Author(s):  
Robert I Colautti
Keyword(s):  
Life History ◽  
Statistical Models ◽  
Propagule Pressure ◽  
Morphological Characteristics ◽  
Ecological Factors ◽  
Salmonid Fishes ◽  
Salmonid Species ◽  
Species Characteristics ◽  
Contrast Group ◽  
Latitudinal Range

Many recent studies of nonindigenous species (NIS) have used life history and morphological characteristics of invaders to either (i) build statistical models that predict new invaders or (ii) test ecological and evolutionary hypotheses. However, species characteristics may be confounded if NIS are transported or introduced nonrandomly with respect to the chosen contrast group, which typically consists of native or globally available species. For example, deliberately introduced NIS are often chosen according to economic rather than ecological factors. Here, I use stocking records of salmonid species introduced into Nevada, USA, to test for propagule biases within this system. I find that established salmonids are introduced significantly more times, and in greater numbers, than are those that fail and that species chosen for introduction are a nonrandom sample of the global salmonid species pool. Statistical differences among characteristics of salmonid species that established, those that were introduced, and those from the global source pool suggest that maximum reported size and weight as well as latitudinal range and midlatitude all represent propagule-biased characteristics of salmonids introduced into Nevada. These results highlight the need for caution when using characteristics of invaders to develop statistical models or to test hypotheses relevant to ecology and evolution.

scholarly journals A Developmental Systems Account of Human Nature

2018 ◽  
Author(s):  
Karola Stotz ◽  
Paul Griffiths
Keyword(s):  
Life History ◽  
Human Nature ◽  
Developmental Plasticity ◽  
Niche Construction ◽  
Life History Trait ◽  
Developmental Systems Theory ◽  
Human Diversity ◽  
Developmental Systems ◽  
Developmental Niche ◽  
Plastic Process

We argue here that to understand human nature is to understand the plastic process of human development and the diversity it produces. Drawing on the framework of developmental systems theory and the idea of developmental niche construction, we argue that human nature is not embodied in only one input to development, such as the genome, and that it should not be confined to universal or typical human characteristics. Both similarities and certain classes of differences are explained by a human developmental system that reaches well out into the ‘environment’. We point to a significant overlap between our account and the ‘life history trait cluster’ account of Grant Ramsey, and defend the developmental systems account against the accusation that trying to encompass developmental plasticity and human diversity leads to an unmanageably complex account of human nature.

scholarly journals Australian black field crickets show changes in neural gene expression associated with socially-induced morphological, life-history, and behavioral plasticity

2016 ◽  
Author(s):  
Michael Kasumovic ◽  
Zhiliang Chen ◽  
Marc R Wilkins
Keyword(s):  
Gene Expression ◽  
Life History ◽  
Developmental Plasticity ◽  
Developmental Trajectories ◽  
Field Cricket ◽  
Phenotypic Traits ◽  
Functional Relationships ◽  
Teleogryllus Commodus ◽  
Black Field ◽  
Insight Into

Background: Ecological and evolutionary model organisms have provided extensive insight into the ecological triggers, adaptive benefits, and evolution of life-history driven developmental plasticity. Despite this, we still have a poor understanding of the underlying genetic changes that occur during shifts towards different developmental trajectories. The goal of this study is to determine whether we can identify underlying gene expression patterns that can describe the different life-history trajectories individuals follow in response to social cues of competition. To do this, we use the Australian black field cricket (Teleogryllus commodus), a species with sex-specific developmental trajectories moderated by the density and quality of calls heard during immaturity. In this study, we manipulated the social information males and females could hear by rearing individuals in either calling or silent treatments. We next used RNA-Seq to develop a reference transcriptome to study changes in brain gene expression at two points prior to sexual maturation. Results: We show accelerated development in both sexes when exposed to calling; changes were also seen in growth, lifespan, and reproductive effort. Functional relationships between genes and phenotypes were apparent from ontological enrichment analysis. We demonstrate that increased phenotypic expression was often associated with the expression of a greater number of genes with similar effect, thus providing a suite of candidate genes for future research in this and other invertebrate organisms. Conclusions: Our results provide interesting insight into the genomic underpinnings of developmental plasticity. We highlight the relationship between genes of known effect and behavioral and phenotypic traits that are under strong sexual selection in Teleogryllus commodus. We also demonstrate the variation in suites of genes associated with different developmental trajectories. Our results provide the opportunity for a genomic exploration of other evolutionary theories such as condition dependence and sexual conflict.

scholarly journals Irreversible impact of early thermal conditions: an integrative study of developmental plasticity linked to mobility in a butterfly species

2022 ◽  
Author(s):  
Anaïs Degut ◽  
Klaus Fischer ◽  
Martin Quque ◽  
François Criscuolo ◽  
Peter Michalik ◽  
...  
Keyword(s):  
Life History ◽  
Seasonal Changes ◽  
Developmental Plasticity ◽  
Thermal Conditions ◽  
Life History Strategies ◽  
Butterfly Species ◽  
Oxidative Markers ◽  
Displacement Capacity ◽  
Irreversible Effects ◽  
Cool Conditions

Within populations, phenotypic plasticity may allow adaptive phenotypic variation in response to selection generated by environmental heterogeneity. For instance, in multivoltine species, seasonal changes between and within generations may trigger morphological and physiological variation enhancing fitness under different environmental conditions. These seasonal changes may irreversibly affect adult phenotypes when experienced during development. Yet, the irreversible effects of developmental plasticity on adult morphology have rarely been linked to life-history traits even though they may affect different fitness components such as reproduction, mobility and self-maintenance. To address this issue, we raised larvae of Pieris napi butterflies under warm or cool conditions to subsequently compare adult performance in terms of reproduction performance (as assessed through fecundity), displacement capacity (as assessed through flight propensity and endurance) and self-maintenance (as assessed through the measurement of oxidative markers). As expected in ectotherms, individuals developed faster under warm conditions and were smaller than individuals developing under cool conditions. They also had more slender wings and showed a higher wing surface ratio. These morphological differences were associated with changes in the reproductive and flight performances of adults, as individuals developing under warm conditions laid fewer eggs and flew larger distances. Accordingly, the examination of their oxidative status suggested that individuals developing under warm conditions invested more strongly into self-maintenance than individuals developing under cool conditions (possibly at the expense of reproduction). Overall, our results indicate that developmental conditions have long-term consequences on several adult traits in butterflies. This plasticity likely acts on life history strategies for each generation to keep pace with seasonal variations and may facilitate acclimation processes in the context of climate change.

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