Ambient noise interferes with auscultatory blood pressure measurement during exercise

In the past decade, there has been a surge of renewed interest in the study of developmental evolution. One approach that has been taken is to examine the expression patterns of a candidate gene in divergent taxa and to use these results to infer which aspects of a particular genetic pathway are either conserved or altered. Here we consider this approach from the perspective of the neo-Darwinian paradigm for evolutionary change. If adaptations are typically composed of large numbers of gene substitutions that are of small effect individually, then the candidate gene approach is unlikely to bridge the gap between developmental pattern and evolutionary process: changes in gene expression patterns may identify the steps in developmental pathways that have been altered during evolution but fail to identify the actual genetic changes that have occurred. On the other hand, there is growing support for the view that adaptations often involve large-effect genes; fortunately, the candidate gene approach is well suited to this type of genetic architecture.     

Developmental-behavioral initiation of evolutionary change.

The traditional approach to evolutionary psychology relies entirely on natural selection as the cause of the evolution of adaptations. Exclusive reliance on natural selection overlooks the fact that changes in development are a necessary prerequisite for evolutionary change. These developmental changes provide the material for natural selection to work on. In the neo-Darwinian scenario, the mechanisms of evolution are mutation or genetic. In the spirit of evolutionary pluralism, the author describes a different 3-stage scenario in which migration (the invasion of new niches or habitats) may occur without mutation or genetic recombination and selection first initiating a change in genes or gene frequencies. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The developmental basis of evolutionary change.

It is a hard-won insight that developmental change is essential to evolution, and the issue has received little consideration in the psychological literature. The origin of the concept can be traced to the nineteenth century biologist St. George Mivart, with the more systematic and extensive treatments of the issue in the early twentieth century by Walter Garstang, Gavin de Beer, and Richard Goldschmidt playing an instrumental role in fleshing out the idea and keeping it alive. Garstang and de Beer held that genetic change, either through selective breeding or mutation, could change the timing of ontogenetic events in various defined ways to give rise to a new species. Goldschmidt felt that a developmental macromutation was necessary to produce a genuine evolutionary novelty. In the view of Garstang, de Beer, and Goldschmidt, a genetic change or mutation is necessary to bring about the developmental changes that lead to evolution. In the present article I utilize the developmental change concept in a different manner than the aforementioned writers. In essence, I describe a different evolutionary pathway, one in which developmental changes in behavior lead to evolutionary change. On this view, genetic change is a secondary or tertiary consequence of enduring behavioral changes brought about by nongenetic alterations of species-typical development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cannabis for migraine treatment: the once and future prescription? An historical and scientific review

Over the past ten years, the discovery and functional characterisation of murine Hox genes has led to a better understanding of some of the molecular mechanisms underlying limb development. It has also shed some light on the potential genetic events which have accompanied the fin-to-limb transition, an evolutionary step of critical importance which opened the way to the evolution of higher vertebrates. This convergence between developmental biology and the sciences of evolution is one of the synergistic interface that has been established recently thanks to the use of genetic engineering and transgenic animals. The increasing number of human genetic syndromes which are derived from mutations in developmental control genes remind us that many human genetic diseases are nothing else but alterations in our developmental programme. Here, we illustrate these various issues by discussing the function of Hox genes during limb development.     

Evolutionary Psychology From a Developmental Systems Perspective: Comment on Lickliter and Honeycutt (2003).

Although agreeing with R. Lickliter and H. Honeycutt (2003; see record 2003-09105-001) that evolutionary psychology lacks and should adopt a coherent developmental model to explain how evolved mechanisms become expressed in phenotypes, it is argued that adhering to the principles of developmental systems theory, despite enhancing evolutionary psychology, would not change appreciably its basic focus. The concepts of innateness and modularity, what is inherited and what evolves, as well as the possible role of developmental plasticity in the evolution of human cognition are discussed. It is proposed that evolutionary psychology can incorporate the developmental systems perspective into its theorizing, with the end result being a science that more closely reflects human nature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental Dynamics and Contemporary Evolutionary Psychology: Status Quo or Irreconcilable Views? Reply to Bjorklund (2003), Krebs (2003), Buss and Reeve (2003), Crawford (2003), and Tooby et al. (2003).

The authors address commentaries by D. F. Bjorklund (2003; see record 200309105-002); D. M. Buss and H. K. Reeve (2003; see record 200309105-004); C. B. Crawford (2003; see record 200309105-005); D. L. Krebs (2003; see record 2003-09105-003); and J. Tooby, L. Cosmides, and H. C. Barrett (2003; see record 2003-09105-006) on their analysis of the underlying assumptions of contemporary evolutionary psychology (R. Lickliter & H. Honeycutt, 2003; see record 200309105-001). The authors argue that evolutionary psychology currently offers no coherent framework for how to integrate genetic, environmental, and experiential factors into a theory of behavioral or cognitive phenotypes. The authors propose that this absence is due to a lack of developmental analysis in the major works of evolutionary psychology, resulting in an almost exclusive focus on adaptationist accounts of evolution by natural selection rather than a more broad-based focus on the process and products of evolution by epigenetic developmental dynamics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Prolegomenon for a Viable Evolutionary Psychology-The Myth and the Reality: Comment on Lickliter and Honeycutt (2003).

R. Lickliter and H. Honeycutt (2003; see record 2003-09105-001) attempted to create a dynamic developmental systems theory of evolutionary psychology. In this commentary, the author argues that the quality of their reasoning, their conflation of evolution and evolution by natural selection, their failure to explain the relative importance of multilevel, epigenetic interactions, their lack of population thinking, and their failure to define adaptation undermines their endeavor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reconstructing the evolution of mind.

Since Darwin, the idea of intellectual continuity has gripped comparative psychology. Psychological evolution has been viewed as the accumulation of gradual changes over time, resulting in an unbroken chain of mental capacities throughout the diversity of life. Some researchers have even maintained that no fundamental psychological differences exist among species. An alternative model argues that a rather profound new psychology related to mental state attribution may have evolved recently in the primate order. The author explores recent experimental research from chimpanzees, rhesus monkeys, and children that is consistent with this 2nd model of psychological evolution. Drawing on the fields of developmental, comparative, and social psychology, as well as evolutionary and developmental biology, the author outlines a research agenda aimed at reconstructing the evolution of metacognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Programming the Drosophila embryo

A critical step in understanding the mechanisms of development is in defining the steps at the molecular, cellular, and organismal levels in the developmental program for a given organism-so that given the egg one can predict not only how the embryo will develop but also how that embryo evolved from its ancestors. Using methods employed by chemists and engineers in modeling hierarchical systems, I have integrated current theory and experiment into a calculational method that can model early Drosophila embryogenesis on a personal computer. This quantitative calculation tool is simple enough to be useful for experimentalists in designing experiments yet detailed enough for theoreticians to derive new insights on the evolution of developmental genetic networks. By integrating the strengths of theoretical and experimental methods into a single engineering model that can compute the cascade of genetic networks in a real organism, I provide a new calculational tool that can apply current theory to current experimental data to study the evolution of developmental programs.     

Two-Stepped Evolutionary Algorithm and Its Application to Stability Analysis of Slopes

Based on genetic algorithm and genetic programming, a new evolutionary algorithm is developed to evolve mathematical models for predicting the behavior of complex systems. The input variables of the models are the property parameters of the systems, which include the geometry, the deformation, the strength parameters, etc. On the other hand, the output variables are the system responses, such as displacement, stress, factor of safety, etc. To improve the efficiency of the evolution process, a two-stepped approach is adopted; the two steps are the structure evolution and parameter optimization steps. In the structure evolution step, a family of model structures is generated by genetic programming. Each model structure is a polynomial function of the input variables. An interpreter is then used to construct the mathematical expression for the model through simplification, regularization, and rationalization. Furthermore, necessary internal model parameters are added to the model structures automatically. For each model structure, a genetic algorithm is then used to search for the best values of the internal model parameters in the parameter optimization step. The two steps are repeated until the best model is evolved. The slope stability problem is used to demonstrate that the present method can efficiently generate mathematical models for predicting the behavior of complex engineering systems.     

Darwin and developmental psychology: Past and present.

Addresses the historical question of what influence Darwin has had on the emergence of developmental psychology as a scientific discipline. Suggestions for possible synergistic connections between modern evolutionary theory and developmental psychology are offered. Darwin's distinctive contributions to evolutionary theory appear to have had less influence on developmental psychology than traditionally believed. Possible reasons for this include developmentalists' commitment to meliorism, conceptual issues characterizing differences between ontogenetic and phylogenetic change, and methodological differences in studying proximate and ultimate factors. It is suggested that developmentalists use evolutionary theory as a heuristic for structuring new research into human development. In return, evolutionary biologists can have hypotheses concerning the impact of phylogeny on human ontogeny tested by those best qualified to test them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Four routes of cognitive evolution.

Four routes of cognitive evolution are distinguished: phylogenetic construction, in which natural selection produces qualitative change to the way a cognitive mechanism operates (language); phylogenetic inflection, in which natural selection biases the input to a cognitive mechanism (imprinting and spatial memory); ontogenetic construction, in which developmental selection alters the way a cognitive mechanism operates (face recognition and theory of mind); and ontogenetic inflection, in which developmental selection changes the input to a cognitive mechanism (imitation). This framework integrates findings from evolutionary psychology (i.e., all research on the evolution of mentality and behavior). In contrast with human nativist evolutionary psychology, it recognizes the adaptive significance of developmental processes, conserves the distinction between cognitive and noncognitive mechanisms, and encompasses research on human and nonhuman animals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral genetics and evolutionary psychology: unified perspective on personality research

Behavioral geneticists and evolutionary psychologists have generally pursued human behavioral analyses with little theoretical or methodological exchange. However, significant benefits might accrue from increased communication between these disciplines. The primary goals of this article are (1) to identify meaningful junctures between behavioral genetics and evolutionary psychology, (2) to describe behavioral genetic research designs and their applications to evolutionary analyses, and (3) to reassess current personality research in light of behavioral genetic and evolutionary concepts and techniques. The five-factor model of personality is conceptualized as subsuming variation in normative species-typical systems with adaptive functions in the human environment of evolutionary adaptation. Considered as universal evolved mechanisms, personality systems are often seen in dynamic conflict within individuals and as highly compartmentalized in their functioning between settings. However, genetically influenced individual differences in personality may also be understood within an evolutionary framework. Studies of the heritability of personality traits indicate broad-sense heritabilities in the 0.40-0.50 range with evidence of substantial nonadditive genetic variation and nonshared environmental influences. Evidence indicates that evolutionary theory (e.g., inclusive fitness theory) predicts patterns of social interaction (e.g., cooperation and bereavement) in relatives. Furthermore, variation in personality may constitute a range of viable strategies matching the opportunities available in the complex niche environment of human societies. Within this wide range of viable strategies, personality variation functions as a resource environment for individuals in the sense that personality variation is evaluated according to the interests of the evaluator (e.g., friendships, coalitions, or mate choice).     

Heterochrony and allometry: the analysis of evolutionary change in ontogeny

The connection between development and evolution has become the focus of an increasing amount of research in recent years, and heterochrony has long been a key concept in this relation. Heterochrony is defined as evolutionary change in rates and timing of developmental processes; the dimension of time is therefore an essential part in studies of heterochrony. Over the past two decades, evolutionary biologists have used several methodological frameworks to analyse heterochrony, which differ substantially in the way they characterize evolutionary changes in ontogenies and in the resulting classification, although they mostly use the same terms. This review examines how these methods compare ancestral and descendant ontogenies, emphasizing their differences and the potential for contradictory results from analyses using different frameworks. One of the two principal methods uses a clock as a graphical display for comparisons of size, shape and age at a particular ontogenic stage, whereas the other characterizes a developmental process by its time of onset, rate, and time of cessation. The literature on human heterochrony provides particularly clear examples of how these differences produce apparent contradictions when applied to the same problem. Developmental biologists recently have extended the concept of heterochrony to the earliest stages of development and have applied it at the cellular and molecular scale. This extension brought considerations of developmental mechanisms and genetics into the study of heterochrony, which previously was based primarily on phenomenological characterizations of morphological change in ontogeny. Allometry is the pattern of covariation among several morphological traits or between measures of size and shape; unlike heterochrony, allometry does not deal with time explicitly. Two main approaches to the study of allometry are distinguished, which differ in the way they characterize organismal form. One approach defines shape as proportions among measurements, based on considerations of geometric similarity, whereas the other focuses on the covariation among measurements in ontogeny and evolution. Both are related conceptually and through the use of similar algebra. In addition, there are close connections between heterochrony and changes in allometric growth trajectories, although there is no one-to-one correspondence. These relationships and outline links between different analytical frameworks are discussed.     

A role of Ultrabithorax in morphological differences between Drosophila species

The mechanisms underlying the evolution of morphology are poorly understood. Distantly related taxa sometimes exhibit correlations between morphological differences and patterns of gene expression, but such comparisons cannot establish how mechanisms evolve to generate diverse morphologies. Answers to these questions require resolution of the nature of developmental evolution within and between closely related species. Here I show how the detailed regulation of the Hox gene Ultrabithorax patterns trichomes on the posterior femur of the second leg in Drosophila melanogaster, and that evolution of Ultrabithorax has contributed to divergence of this feature among closely related species. The cis-regulatory regions of Ultrabithorax, and not the protein itself, appear to have evolved. This study provides experimental evidence that cis-regulatory evolution is one way in which conserved proteins have promoted morphological diversity.     

Evolvability

Evolvability is an organism's capacity to generate heritable phenotypic variation. Metazoan evolution is marked by great morphological and physiological diversification, although the core genetic, cell biological, and developmental processes are largely conserved. Metazoan diversification has entailed the evolution of various regulatory processes controlling the time, place, and conditions of use of the conserved core processes. These regulatory processes, and certain of the core processes, have special properties relevant to evolutionary change. The properties of versatile protein elements, weak linkage, compartmentation, redundancy, and exploratory behavior reduce the interdependence of components and confer robustness and flexibility on processes during embryonic development and in adult physiology. They also confer evolvability on the organism by reducing constraints on change and allowing the accumulation of nonlethal variation. Evolvability may have been generally selected in the course of selection for robust, flexible processes suitable for complex development and physiology and specifically selected in lineages undergoing repeated radiations.     

Mapping in plants: progress and prospects

Comprehensive genetic maps are now available for all of the world's important crop species. Data show a remarkable conservation of order of markers over family-wide taxonomic groupings and illuminate species relationships and mechanisms of genome evolution. Comparison of genetic and physical maps has revealed differences in genetic distance throughout genomes with implications for genome organization, gene isolation and transformation.     

On evolutive systems and the initial evolution of structure and function

As an instrument for the study of the early stages of evolution, we introduce evolutive systems, defined as systems that have the capacity to evolve given appropriate conditions in their environment. They consist of building blocks (e.g. monomers) that are either stable or in steady supply, and of transient assemblies (e.g. polymers) that are entities of great variety, some of which are capable of function. Evolution leads to the accumulation of structure within the transient assemblies during repeated cycles of disintegration (partial or total) and reassembly, on account of the selective advantages associated with transient assembly functions. Transient assemblies must be either inherently unstable or subject to disintegration by agents in their environment. Evolutive systems must have access to a negentropy input in the form of energy in packets larger than typical thermal energies. Reproduction, although not a prerequisite, greatly affects the capacity of evolutive systems to evolve, and thus can be expected to appear in an evolutive system if at all possible. Similarly, functions that require the expenditure of negentropy (for example mobility, breathing, circulation, sensing, communicating, etc.) are not prerequisites for evolution, but can be expected to become established in evolutive systems during evolution through the selective advantages that they confer. A computer-based evolutive automaton is used to explore possible evolutionary scenarios. In the presence of spatial and temporal inhomogeneities, one can construct a multitude of evolutionary scenarios through which various functions, such as the operation of genetic code, can become established within the evolutive automaton. This variety of possible evolutionary scenarios is all the more remarkable because the automaton does not include many important physical processes that would be present in a real system and would greatly multiply the number of possible evolutionary mechanisms and scenarios. Some evolutionary mechanisms are based on survival related selection, while others are based on generation related selection. Previously explored scenarios for the initiation of life have been based mostly on generation related selection. In this paper, we give particular emphasis to survival related selection which is more general in that it does apply to structures and functions related to reproduction but, unlike generation related selection, it is not limited to them. Some of the most basic features of terrestrial living systems can be seen either as prerequisite features of an evolutive system (such as the mortality of living organisms, instability of biological polymers, imperfect reproduction caused by mutations, and the need for a negentropy input) or as features that one can reasonably expect to become established in an evolutive system (such as reproduction and the multitude of living functions that require expenditure of negentropy). This suggests the possibility that an independent definition of living systems may not be necessary if features of living systems substantially overlap with features that one may expect to find in evolutive systems.     

Darwinian adaptation, population genetics and the streetcar theory of evolution

This paper investigates the problem of how to conceive a robust theory of phenotypic adaptation in non-trivial models of evolutionary biology. A particular effort is made to develop a foundation of this theory in the context of n-locus population genetics. Therefore, the evolution of phenotypic traits is considered that are coded for by more than one gene. The potential for epistatic gene interactions is not a priori excluded. Furthermore, emphasis is laid on the intricacies of frequency-dependent selection. It is first discussed how strongly the scope for phenotypic adaptation is restricted by the complex nature of 'reproduction mechanics' in sexually reproducing diploid populations. This discussion shows that one can easily lose the traces of Darwinism in n-locus models of population genetics. In order to retrieve these traces, the outline of a new theory is given that I call 'streetcar theory of evolution'. This theory is based on the same models that geneticists have used in order to demonstrate substantial problems with the 'adaptationist programme'. However, these models are now analyzed differently by including thoughts about the evolutionary removal of genetic constraints. This requires consideration of a sufficiently wide range of potential mutant alleles and careful examination of what to consider as a stable state of the evolutionary process. A particular notion of stability is introduced in order to describe population states that are phenotypically stable against the effects of all mutant alleles that are to be expected in the long-run. Surprisingly, a long-term stable state can be characterized at the phenotypic level as a fitness maximum, a Nash equilibrium or an ESS. The paper presents these mathematical results and discusses - at unusual length for a mathematical journal - their fundamental role in our current understanding of evolution.