Ecological Opportunity In Adaptive Radiation Of Galapagos Endemic Land Snails

The classic evolutionary hypothesis of ecological opportunity proposes that both heterogeneity of resources and freedom from enemies promote phenotypic divergence as a response to increased niche availability. Although phenotypic divergence and speciation have often been inferred to be the primary consequences of the release from competition or predation that accompanies a shift to a new adaptive zone, increased phenotypic variation within species is expected to represent the first stage resulting from such a shift. Using measures of intraspecific morphological variation of 30 species of Galapagos endemic land snails in a phylogenetically controlled framework, we show that the number of local congeners and the number of local plant species are associated with lower and higher intraspecific phenotypic variation, respectively. In this clade, ecological opportunity thus explicitly links the role of competition from congeners and the heterogeneity of resources to the extent of intraspecific phenotypic divergence as adaptive radiation proceeds.Integrative Biolog

Developmental Heterochrony And The Evolution Of Autistic Perception, Cognition And Behavior

Background Autism is usually conceptualized as a disorder or disease that involves fundamentally abnormal neurodevelopment. In the present work, the hypothesis that a suite of core autism-related traits may commonly represent simple delays or non-completion of typical childhood developmental trajectories is evaluated. Discussion A comprehensive review of the literature indicates that, with regard to the four phenotypes of (1) restricted interests and repetitive behavior, (2) short-range and long-range structural and functional brain connectivity, (3) global and local visual perception and processing, and (4) the presence of absolute pitch, the differences between autistic individuals and typically developing individuals closely parallel the differences between younger and older children. Summary The results of this study are concordant with a model of ‘developmental heterochrony’, and suggest that evolutionary extension of child development along the human lineage has potentiated and structured genetic risk for autism and the expression of autistic perception, cognition and behavior

Why and How Imprinted Genes Drive Fetal Programming

Imprinted genes mediate fetal and childhood growth and development, and early growth patterns drive fetal programming effects. However, predictions and evidence from the kinship theory of imprinting have yet to be directly integrated with data on fetal programming and risks of metabolic disease. I first define paternal-gene and maternal-gene optima with regard to early human growth and development. Next, I review salient evidence with regard to imprinted gene effects on birth weight, body composition, trajectories of feeding and growth, and timing of developmental stages, to evaluate why and how imprinted gene expression influences risks of metabolic disease in later life. I find that metabolic disease risks derive primarily from maternal gene biases that lead to reduced placental efficacy, low birth weight, low relative muscle mass, high relative white fat, increased abdominal adiposity, reduced pancreatic β-cell mass that promotes insulin resistance, reduced appetite and infant sucking efficacy, catch-up fat deposition from family foods after weaning, and early puberty. Paternal gene biases, by contrast, may contribute to metabolic disease via lower rates of brown fat thermiogenesis, and through favoring more rapid postnatal catch-up growth after intrauterine growth restriction from environmental causes. These disease risks can be alleviated through dietary and pharmacological alterations that selectively target imprinted gene expression and relevant metabolic pathways. The kinship theory of imprinting, and mother-offspring conflict more generally, provide a clear predictive framework for guiding future research on fetal programming and metabolic disease

Cognitive-Behavioral Phenotypes of Williams Syndrome Are Associated With Genetic Variation in the GTF2I Gene, In a Healthy Population

Background Individuals with Williams syndrome, a neurogenetic condition caused by deletion of a set of genes at chromosomal location 7q11.23, exhibit a remarkable suite of traits including hypersociality with high, nonselective friendliness and low social anxiety, expressive language relatively well-developed but under-developed social-communication skills overall, and reduced visual-spatial abilities. Deletions and duplications of the Williams-syndrome region have also been associated with autism, and with schizophrenia, two disorders centrally involving social cognition. Several lines of evidence have linked the gene GTF2I (General Transcription Factor IIi) with the social phenotypes of Williams syndrome, but a role for this gene in sociality within healthy populations has yet to be investigated. Results We genotyped a large set of healthy individuals for two single-nucleotide polymorphisms in the GTF2I gene that have recently been significantly associated with autism, and thus apparently exhibit functional effects on autism-related social phenotypes. GTF2I genotypes for these SNPs showed highly significant association with low social anxiety combined with reduced social-communication abilities, which represents a metric of the Williams-syndrome cognitive profile as described from previous studies. Conclusions These findings implicate the GTF2I gene in the neurogenetic basis of social communication and social anxiety, both in Williams syndrome and among individuals in healthy populations

Parent‐Offspring Conflict in the Evolution of Vertebrate Reproductive Mode

Abstract: We propose and evaluate the hypothesis that parent‐offspring conflict over the degree of maternal investment has been one of the main selective factors in the evolution of vertebrate reproductive mode. This hypothesis is supported by data showing that the assumptions of parent‐offspring conflict theory are met for relevant taxa; the high number of independent origins of viviparity, matrotrophy (direct maternal‐fetal nutrient transfer), and hemochorial placentation (direct fetal access to the maternal bloodstream); the extreme diversity in physiological and morphological aspects of viviparity and placentation, which usually cannot be ascribed adaptive significance in terms of ecological factors; and divergent and convergent patterns in the diversification of placental structure, function, and developmental genetics. This hypothesis is also supported by data demonstrating that embryos and fetuses actively manipulate their interaction with the mother, thereby garnishing increased maternal resources. Our results indicate that selection may favor adaptations of the mother, the fetus, or both in traits related to reproductive mode and that integration of physiological and morphological data with evolutionary ecological data will be required to understand the adaptive significance of interspecific variation in viviparity, matrotrophy, and placentation

Subsociality and female reproductive success in a mycophagous thrips: An observational and experimental analysis

Oviparous females of the haplodiploid, facultatively viviparous thrips Elaphrothrips tuberculatus (Thysanoptera: Phlaeothripidae) guard their eggs against female conspecifics and other egg predators. The intensity of maternal defense increases with clutch size. Field and laboratory observations indicate that cannibalism by females is an important selective pressure favoring maternal care. Experimental removals of guarding females showed that egg guarding substantially increases egg survivorship and that the survivorship of undefended eggs is higher in the absence of nonguarding female conspecifics than in their presence. The fecundity of viviparous females increases with the number of eggs cannibalized. The reproductive success of oviparous females increases with body size and local food density and decreases with local density of breeding females. Social behavior may not have advanced beyond maternal care in Elaphrothrips tuberculatus because, relative to Hymenoptera, capabilities for helping relatives are few or nonexistent, and the causes of variation in female reproductive success are not influenced easily by cooperation among females .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44947/1/10905_2005_Article_BF01049195.pd

Special issue: Kin Selection Inclusive fitness theory for the evolution of religion

Keywords: inclusive fitness kinship religious behaviour We describe and evaluate an integrative hypothesis for the origin and evolution of human religious cognition and behaviour, based on maximization of inclusive fitness. By this hypothesis, the concept of God is represented by one's circle of kin and social salience, such that serving God and serving this circle become synonymous. The theory is supported by data from anthropology, evolutionary theory, psychology, neuroscience, psychiatry, endocrinology and genetics. It is largely compatible with, yet can subsume, previous theories of religion that are also based on adaptation and natural selection. Ó 2014 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. There is something sacred about kinship, as most social anthropologists who have studied its operation in the field are prepared to admit One human phenotype, religious behaviour, stands apart from all others with regard to its dominating emphasis on altruism and prosociality. This set of behaviours has yet to be analysed explicitly and comprehensively in the context of inclusive fitness theory, using the conceptual tools developed in Hamilton's wake for understanding its origins, maintenance and diversification. Like eusociality, or cooperative breeding, religion can be considered as a sociobehavioural system that has evolved in the contexts of genetic relatedness, parental manipulation (generalized here as asymmetries in control over phenotypes) and mutualism. In this article we describe and analyse an integrative theory, based on inclusive fitness maximization, for understanding the origin and evolution of religious behaviour and the concepts of God and supernatural agents. The theory is based mainly on works by Hamilton, Alexander, Trivers, Lahti, Coe, Palmer and Steadman, and it draws together evidence from anthropology, psychology, neuroscience, psychiatry, endocrinology and genetics into a unified, testable framework. The theory is novel specifically in its integrative, synthetic and reconciliatory nature, and its central emphasis on the roles of genetic relatedness and inclusive fitness in the evolution of religion. We first categorize and describe previous theories regarding the origins, bases and functions of the concept of God and other supernatural agents, and associated religious behaviour. Next, we present the theory, and discuss how it relates to, and can subsume, these earlier ideas without being strongly incompatible with any of them. We also discuss empirical evidence that bears upon the theory, and suggest opportunities for additional tests of its predictions. PREVIOUS THEORIES Previous ideas regarding the evolution of religion and concepts of God address diverse aspects of religious phenomena, at different levels of analysis, either proximate (dealing with mechanisms), or ultimate (dealing with selective pressures and other evolutionary causes). Moreover, studies of religion may focus on its supernatural components, its moralizing elements, or both in conjunction

Special issue: Kin Selection Inclusive fitness theory for the evolution of religion

Keywords: inclusive fitness kinship religious behaviour We describe and evaluate an integrative hypothesis for the origin and evolution of human religious cognition and behaviour, based on maximization of inclusive fitness. By this hypothesis, the concept of God is represented by one's circle of kin and social salience, such that serving God and serving this circle become synonymous. The theory is supported by data from anthropology, evolutionary theory, psychology, neuroscience, psychiatry, endocrinology and genetics. It is largely compatible with, yet can subsume, previous theories of religion that are also based on adaptation and natural selection. Ó 2014 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. There is something sacred about kinship, as most social anthropologists who have studied its operation in the field are prepared to admit One human phenotype, religious behaviour, stands apart from all others with regard to its dominating emphasis on altruism and prosociality. This set of behaviours has yet to be analysed explicitly and comprehensively in the context of inclusive fitness theory, using the conceptual tools developed in Hamilton's wake for understanding its origins, maintenance and diversification. Like eusociality, or cooperative breeding, religion can be considered as a sociobehavioural system that has evolved in the contexts of genetic relatedness, parental manipulation (generalized here as asymmetries in control over phenotypes) and mutualism. In this article we describe and analyse an integrative theory, based on inclusive fitness maximization, for understanding the origin and evolution of religious behaviour and the concepts of God and supernatural agents. The theory is based mainly on works by Hamilton, Alexander, Trivers, Lahti, Coe, Palmer and Steadman, and it draws together evidence from anthropology, psychology, neuroscience, psychiatry, endocrinology and genetics into a unified, testable framework. The theory is novel specifically in its integrative, synthetic and reconciliatory nature, and its central emphasis on the roles of genetic relatedness and inclusive fitness in the evolution of religion. We first categorize and describe previous theories regarding the origins, bases and functions of the concept of God and other supernatural agents, and associated religious behaviour. Next, we present the theory, and discuss how it relates to, and can subsume, these earlier ideas without being strongly incompatible with any of them. We also discuss empirical evidence that bears upon the theory, and suggest opportunities for additional tests of its predictions. PREVIOUS THEORIES Previous ideas regarding the evolution of religion and concepts of God address diverse aspects of religious phenomena, at different levels of analysis, either proximate (dealing with mechanisms), or ultimate (dealing with selective pressures and other evolutionary causes). Moreover, studies of religion may focus on its supernatural components, its moralizing elements, or both in conjunction