Adaptive Evolution

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Adaptive Evolution ◽  
Evolutionary Biology ◽  
Adaptive Design ◽  
Late Nineteenth Century ◽  
Evolutionary Analysis ◽  
Developmental Constraint ◽  
Heritable Variation ◽  
Phylogenetic Constraint ◽  
Long Time ◽  
As If

Adaptive evolution—phenotypic improvement due to selection—is the central theme of Darwinian evolutionary biology. The concept of adaptive evolution by selection on heritable variation underlies every evolutionary analysis of form, function, and fitness. How biologists view adaptive evolution— how they are taught to view it—has a profound influence on thinking and research in virtually every area of biology. Despite the importance of adaptive evolution, there is still controversy over how to relate development and selection in discussions of adaptive design (e.g. see Charlesworth, 1990; Amundson, 1996). It is a controversy that began in the late nineteenth century, when biologists unfortunately began to dichotomize development and selection, as if they were opposing factors in evolution (see the discussion of gradualism in chapter 24). The modern version of this debate dichotomizes selection and developmental constraints (e.g., see Maynard Smith et al., 1985; Bell, 1989; Ridley, 1993; Amundson, 1996; see also chapter 1). Phylogenetic constraint is another version of developmental constraint, since it refers to limits imposed by ancestry (inherited developmental patterns) on current form as does the idea of developmental constraint. The dichotomy between selection and development, as if they were opposed factors in adaptive evolution, is misconceived. Adaptive evolution is a two-step process: first the generation of variation by development, then the screening of that variation by selection (Mayr, 1962; Endler and McLellan, 1988, p. 395). If an established trait (one widespread in a population) persists through phylogenetic branching events, this is not evidence against selection as an explanation for the trait (cf. Coddington, 1988), as if speciation reduces the importance of selection. Rather, it could be taken as evidence that selection is important for maintenance of the trait in more than one lineage: trait persistence over long time spans certainly does not represent absence of continued selection, since it is known that traits no longer favored by selection, such as the eyes of cave animals and walking limbs in whales, are often lost (for other classic examples, see Rensch, 1960).

scholarly journals Integrated structural and evolutionary analysis reveals common mechanisms underlying adaptive evolution in mammals

2020 ◽  
Vol 117 (11) ◽  
pp. 5977-5986 ◽  
Author(s):  
Greg Slodkowicz ◽  
Nick Goldman
Keyword(s):  
Positive Selection ◽  
Adaptive Evolution ◽  
Evolutionary Biology ◽  
Molecular Mechanisms ◽  
Structural Information ◽  
Protein Structures ◽  
Unexpected Finding ◽  
Evolutionary Analysis ◽  
Genomic Scale ◽  
Evolution Of Mammals

Understanding the molecular basis of adaptation to the environment is a central question in evolutionary biology, yet linking detected signatures of positive selection to molecular mechanisms remains challenging. Here we demonstrate that combining sequence-based phylogenetic methods with structural information assists in making such mechanistic interpretations on a genomic scale. Our integrative analysis shows that positively selected sites tend to colocalize on protein structures and that positively selected clusters are found in functionally important regions of proteins, indicating that positive selection can contravene the well-known principle of evolutionary conservation of functionally important regions. This unexpected finding, along with our discovery that positive selection acts on structural clusters, opens previously unexplored strategies for the development of better models of protein evolution. Remarkably, proteins where we detect the strongest evidence of clustering belong to just two functional groups: Components of immune response and metabolic enzymes. This gives a coherent picture of pathogens and xenobiotics as important drivers of adaptive evolution of mammals.

Developmental Plasticity and Evolution

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Adaptive Evolution ◽  
Evolutionary Biology ◽  
Developmental Plasticity ◽  
Higher Plants ◽  
Critical Discussion ◽  
Physiological Adaptation ◽  
Modular Organization ◽  
Random Mutation ◽  
Environmental Induction ◽  
Development And Evolution

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.

scholarly journals El binomio discapacidad-enfermedad: un análisis crítico / The Disability-Disease Pairing: A Critical Analysis

2012 ◽  
Vol 1 (1) ◽  
Author(s):  
Francisco Guzmán Castillo
Keyword(s):  
Critical Analysis ◽  
Chronically Ill ◽  
Medical Rehabilitation ◽  
Legal Documents ◽  
Medical Gaze ◽  
The Social ◽  
Long Time ◽  
As If

ABSTRACTDisease and disability are two concepts closely linked for a long time, so that the second seems to be merely a consequence of the first. Even today both realities are treated as if they were the same thing in many public contexts and legal documents. However, this link between disease and disability is not as unavoidable as is often implied. According to the approach outlined in this paper it comes to different realities that are interpreted as part of the same thing under the code of the medical gaze. This paper presents and critically analyzes the archaeological origin of the interpretation of the person with disabilities and chronically ill in the discourse called «medical rehabilitation». Under this paradigm is imposed on the person with disabilities the social mandate to rehabilitate and/or cure to, so, be reintegrated and contribute to society. Otherwise, will be doomed to exclusion.RESUMENEnfermedad y discapacidad son dos conceptos estrechamente vinculados entre sí desde hace mucho tiempo, de manera que la segunda no parece más que una consecuencia de la primera. Aún hoy se tratan ambas realidades como si fueran la misma cosa en multitud de contextos públicos y documentos jurídicos. Sin embargo, este vínculo entre enfermedad y discapacidad no es tan ineludible como a menudo se da a entender. Según el planteamiento expuesto en este trabajo, se trata de realidades distintas que son interpretadas como parte de una misma cosa bajo el código de la mirada médica. Este trabajo presenta y analiza de forma crítica el origen arqueológico de la interpretación de la persona con discapacidad como un enfermo crónico dentro del discurso que se denomina «médico-rehabilitador». Bajo este paradigma se impone a la persona con discapacidad el mandato social de que se rehabilite y/o se cure para, de esta manera, poder reinsertarse y aportar a la sociedad. De lo contrario, quedará condenado a la exclusión.

scholarly journals Comparative analysis of chloroplast genomes for five Dicliptera species (Acanthaceae): molecular structure, phylogenetic relationships, and adaptive evolution

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8450 ◽  
Author(s):  
Sunan Huang ◽  
Xuejun Ge ◽  
Asunción Cano ◽  
Betty Gaby Millán Salazar ◽  
Yunfei Deng
Keyword(s):  
Adaptive Evolution ◽  
Phylogenetic Relationships ◽  
Single Copy ◽  
Rrna Genes ◽  
Trna Genes ◽  
Evolutionary Analysis ◽  
Protein Coding ◽  
Variable Regions ◽  
Protein Coding Genes ◽  
Chloroplast Genomes

The genus Dicliptera (Justicieae, Acanthaceae) consists of approximately 150 species distributed throughout the tropical and subtropical regions of the world. Newly obtained chloroplast genomes (cp genomes) are reported for five species of Dilciptera (D. acuminata, D. peruviana, D. montana, D. ruiziana and D. mucronata) in this study. These cp genomes have circular structures of 150,689–150,811 bp and exhibit quadripartite organizations made up of a large single copy region (LSC, 82,796–82,919 bp), a small single copy region (SSC, 17,084–17,092 bp), and a pair of inverted repeat regions (IRs, 25,401–25,408 bp). Guanine-Cytosine (GC) content makes up 37.9%–38.0% of the total content. The complete cp genomes contain 114 unique genes, including 80 protein-coding genes, 30 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Comparative analyses of nucleotide variability (Pi) reveal the five most variable regions (trnY-GUA-trnE-UUC, trnG-GCC, psbZ-trnG-GCC, petN-psbM, and rps4-trnL-UUA), which may be used as molecular markers in future taxonomic identification and phylogenetic analyses of Dicliptera. A total of 55-58 simple sequence repeats (SSRs) and 229 long repeats were identified in the cp genomes of the five Dicliptera species. Phylogenetic analysis identified a close relationship between D. ruiziana and D. montana, followed by D. acuminata, D. peruviana, and D. mucronata. Evolutionary analysis of orthologous protein-coding genes within the family Acanthaceae revealed only one gene, ycf15, to be under positive selection, which may contribute to future studies of its adaptive evolution. The completed genomes are useful for future research on species identification, phylogenetic relationships, and the adaptive evolution of the Dicliptera species.

ROLE OF THE COURTS

PEDIATRICS ◽  
1973 ◽  
Vol 51 (4) ◽  
pp. 796-798
Author(s):  
Florence M. Kelley
Keyword(s):  
Social Work ◽  
Juvenile Court ◽  
Family Court ◽  
Court System ◽  
The Family ◽  
Long Time ◽  
Neglected Children ◽  
Abused And Neglected Children ◽  
As If

It is important to know what the courts can do and cannot do in the area of abused and neglected children. Often the Family Court is listed as an agency. It is not an agency. It is part of the court system. Its operation is circumscribed by the concept of being a real court. For a long time there was a theory that the Family Court or Juvenile Court could be a kind of social work oriented operation, not quite a real court, not truly a social work agency. This concept has been abandoned. The Family Court is a court of record and is in all aspects a court. It is dependent in the action it takes on evidence which must conform to strict rules that are laid down. It is an adversary proceeding. It is not enough to produce a child that looks as if it has been beaten. A judge in the Family Court also has before him the person who may be charged with having beaten the child. That person, be it a parent or guardian, is entitled to counsel, to help in his defense. The adversary process then takes place. Persons bring forth evidence to show that the parent did abuse the child. The parent is enabled under the court system to bring forth before the judge evidence that he or she did not do it. It is then up to the judge to give this evidence due weight and make a decision as to whether or not the allegations have been proven.

Piecing Together a Past

2015 ◽  
Author(s):  
Richard Bradley
Keyword(s):  
Twentieth Century ◽  
Present Account ◽  
The Past ◽  
Single Period ◽  
Previous Decade ◽  
Long Time ◽  
Single Method ◽  
Century Thought ◽  
With Memory ◽  
As If

Piecing Together the Past was one of the last books by Gordon Childe. It was published in 1955 and drew on a series of lectures he had given over the previous decade. Every chapter asked a question. The most difficult was: ‘What happened in prehistory?’ There might be disagreements over particular answers, but they would be based on a single method of analysis, for it seemed as if there was only one past to study. The authors of the present volume take a different view, for, no matter which monuments they consider, they find evidence of many separate pasts. Some of those histories were invoked at different times, and others were advocated simultaneously but by different groups of people. There was far more diversity than Childe allowed. It may have happened because his account was concerned exclusively with prehistory and with its significance for twentieth-century thought. What took place in between was overlooked, for in 1955 few scholars envisaged a past within the past. Those who did so were more concerned with the development of archaeology as a discipline. Childe’s procedure was like that of field projects which disregard later structures to focus on a single period. Childe was concerned with artefacts as well as monuments, but the present account considers the evidence of buildings and related structures. It is a vital distinction. Small objects might have been discovered by chance or could have circulated for a long time as heirlooms. Monuments, however, were impossible to overlook. They might be ignored as unacceptable beliefs were rejected, they might even be destroyed, but in every case their presence demanded some response. It is conventional to associate monuments with memory, as that invokes the Latin verb monere, to remind. This equation is problematical. It is implausible that a single version of the past would remain unaltered for long and more likely that it was revised as circumstances changed. At the same time, forgetting is an important cultural process (Forty and Küchler 1999) and ideas could lose their force surprisingly quickly.

Created Soul—Eternal Spirit: A Continuing Theological Thorn

1966 ◽  
Vol 19 (1) ◽  
pp. 23-34
Author(s):  
Kenneth Hamilton
Keyword(s):  
Human Consciousness ◽  
Time And Space ◽  
Long Time ◽  
God's Image ◽  
Spiritual Consciousness ◽  
As If

Discussing in the Institutes the nature of God's image in man, Calvin refers to the dream of the Manichees, which Servetus has attempted in our own day to revive. Because it is said that God breathed into man's nostrils the breath of life (Gen. 2.7), they thought that the soul was a transmission of the substance of God; as if some portion of the boundless divinity had passed into man. It cannot take long time to show how many gross and foul absurdities this devilish error carries in its train.1In our own day this view, which Calvin takes to be so fatal an error, is very much alive. Occasionally it is expressed in terms not dissimilar from those described by Calvin.2 More often, however, it appears in a more generalised form, where man's possession of a spiritual consciousness is taken to prove that the Divine is latent within him. Spirit is regarded above all as the vehicle by means of which the eternal penetrates the temporal. God himself moves in man, so that human consciousness cannot be satisfied with anything belonging to time and space, our transient world; instead, it strives continually to attain to its proper supramundane dimension.The Platonic inspiration of such a view is evident when it is advanced as a distinctive argument: for example, in Rufus M. Jones' West Lectures, Spirit in Man.3

The Unbearable Lightness of Wartime Cuisine

2005 ◽  
Vol 5 (2) ◽  
pp. 26-36
Author(s):  
alma marin
Keyword(s):  
The World ◽  
Long Time ◽  
As If

The world has always been imperfect. I just didn't pay much attention, like so many people who go about their lives ignoring atrocities, war, hunger as if such things happened only in books or films. And even when I found myself in the middle of the chaos of war, for a long time I thought that I would awaken into a beautiful spring morning and realize it was all a bad dream. In those years, my life spun around one word: survival. That meant coping with existence without water, electricity, and with very little food; queuing in lines for hours under incessant shell and sniper fire to get basic things that are normally taken for granted.

scholarly journals The Adaptive Evolution and Gigantism Mechanisms of the Hadal “Supergiant” Amphipod Alicella gigantea

2021 ◽  
Vol 8 ◽  
Author(s):  
Wenhao Li ◽  
Faxiang Wang ◽  
Shouwen Jiang ◽  
Binbin Pan ◽  
Jiulin Chan ◽  
...  
Keyword(s):  
Adaptive Evolution ◽  
Growth Regulation ◽  
Evolutionary Rate ◽  
Phylogenetic Analyses ◽  
Whole Body ◽  
Evolutionary Analysis ◽  
Weight Measurement ◽  
Codon Substitution ◽  
Limited Food ◽  
New Britain

Hadal trenches are commonly referred to as the deepest areas in the ocean and are characterized by extreme environmental conditions such as high hydrostatic pressures and very limited food supplies. Amphipods are considered the dominant scavengers in the hadal food web. Alicella gigantea is the largest hadal amphipod and, as such, has attracted a lot of attention. However, the adaptive evolution and gigantism mechanisms of the hadal “supergiant” remain unknown. In this study, the whole-body transcriptome analysis was conducted regarding the two hadal amphipods, one being the largest sized species A. gigantea from the New Britain Trench and another the small-sized species Bathycallisoma schellenbergi from the Marceau Trench. The size and weight measurement of the two hadal amphipods revealed that the growth of A. gigantea was comparatively much faster than that of B. schellenbergi. Phylogenetic analyses showed that A. gigantea and B. schellenbergi were clustered into a Lysianassoidea clade, and were distinct from the Gammaroidea consisting of shallow-water Gammarus species. Codon substitution analyses revealed that “response to starvation,” “glycerolipid metabolism,” and “meiosis” pathways were enriched among the positively selected genes (PSGs) of the two hadal amphipods, suggesting that hadal amphipods are subjected to intense food shortage and the pathways are the main adaptation strategies to survive in the hadal environment. To elucidate the mechanisms underlying the gigantism of A. gigantea, small-sized amphipods were used as the background for evolutionary analysis, we found the seven PSGs that were ultimately related to growth and proliferation. In addition, the evolutionary rate of the gene ontology (GO) term “growth regulation” was significantly higher in A. gigantea than in small-sized amphipods. By combining, those points might be the possible gigantism mechanisms of the hadal “supergiant” A. gigantea.

scholarly journals Does Adaptive Protein Evolution Proceed by Large or Small Steps at the Amino Acid Level?

2018 ◽  
Author(s):  
Juraj Bergman ◽  
Adam Eyre-Walker
Keyword(s):  
Amino Acids ◽  
Adaptive Evolution ◽  
Evolutionary Biology ◽  
Amino Acid Level ◽  
Neutral Evolution ◽  
Relative Contribution ◽  
Mutational Step ◽  
Genome Wide ◽  
Genome Wide Data ◽  
Evolution Of Proteins

AbstractA longstanding question in evolutionary biology is the relative contribution of large and small effect mutations to the adaptive process. We have investigated this question in proteins by estimating the rate of adaptive evolution between all pairs of amino acids separated by one mutational step using a McDonald-Kreitman type approach and genome-wide data from several Drosophila species. We find that the rate of adaptive evolution is higher amongst amino acids that are more similar. This is partly due to the fact that the proportion of mutations that are adaptive is higher amongst more similar amino acids. We also find that the rate of neutral evolution between amino acids is higher amongst similar amino acids. Overall our results suggest that both the adaptive and non-adaptive evolution of proteins is dominated by substitutions between amino acids that are more similar.

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