Principles of Development and Evolution

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
General Framework ◽  
Developmental Plasticity ◽  
Developmental Change ◽  
Gradual Improvement ◽  
Population Extinction ◽  
Founder Populations ◽  
New Gene ◽  
New Situation ◽  
Development And Evolution

So far, I have outlined the general properties of phenotypes, shown how they relate to development, and presented a model of adaptive evolution based on established principles of development and genetics. Now, using this general framework, I can summarize how developmental plasticity facilitates evolution. Jacob (1977) characterized evolution as “tinkering.” It shuffles and recombines what is already there. Frazzetta (1975), in another felicitous comparison with machines, wrote that evolution manages “the gradual improvement of a machine while it is running” (p. 20). Both of these qualities are possible due to characteristics of phenotypes that are not shared with most machines. Tinkering works because the phenotype is made of recombinable modular components that can be turned off and on in different conditions and can function in more than one context, what Gerhart and Kirshner (1997; Kirschner and Gerhart, 1998) call “weak linkage” to any particular use. Improvement without disruption of function works because of the remarkable active flexibility, and redundancy, in the development of parts. As a result of these two qualities—modularity and plasticity—an organism has the unmachinelike ability to respond to a new situation or to a new gene with the production of a new trait, and then to multiply, through reproduction, the ability to produce this trait. Differential reproduction starts the cycle of variation, selection, and cross-generational change that we call evolution—the most unmachinelike process of all. Many reasons have been given to believe that evolutionary change is difficult and even resisted in a well-adapted population (see chapter 1). The evolution of a novel specialization requires that a single lineage persist while undergoing extensive change. The conditions sometimes mentioned as favoring directional evolution, such as strong competition, very different or changing environments, small founder populations, or very long periods of time (see Mayr, 1982b), also favor population extinction. The idea of developmental cohesiveness, outlined in chapter 1, led to the further belief that major developmental change early in ontogeny would be disruptive. The cohesiveness theme persists even though it long has been clear that innovation does not occur exclusively by terminal addition (see chapter 1).

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.

Approaching the Doctrine of Divine Love

Love Divine ◽  
2020 ◽  
pp. 9-38
Author(s):  
Jordan Wessling
Keyword(s):  
New Testament ◽  
General Framework ◽  
Divine Love ◽  
Human Love ◽  
God's Love ◽  
Reliable Source ◽  
Central Argument ◽  
Insight Into

Chapter 1 is methodological and sets the stage for many of the modes of reasoning found within the remainder of the book. The central argument is that reflection upon ideal human love can be used as a reliable source for gaining significant insight into the nature of God’s love. More specifically, reasons are presented for believing that various New Testament authors presuppose that divine and human love (or species of each) are similar in such a way that scrutiny of how humans ideally should love can be used fruitfully to inform how Christian theologians and philosophers think of God’s perfect love. This methodological conclusion provides a foundation for the construction of a model of God’s love found in Chapter 2, and it offers the beginnings of a more general framework for considering certain kinds of actions relevant to this book that God might, or might not, be inclined to perform.

scholarly journals Resolving homology in the face of shifting germ layer origins: Lessons from a major skull vault boundary

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Camilla S Teng ◽  
Lionel Cavin ◽  
Robert E Maxson ◽  
Marcelo R Sánchez-Villagra ◽  
J Gage Crump
Keyword(s):  
Neural Crest ◽  
General Framework ◽  
Model Organisms ◽  
Germ Layer ◽  
Coronal Suture ◽  
Flexible Joints ◽  
Fundamental Knowledge ◽  
Skull Vault ◽  
The Face ◽  
Development And Evolution

The vertebrate skull varies widely in shape, accommodating diverse strategies of feeding and predation. The braincase is composed of several flat bones that meet at flexible joints called sutures. Nearly all vertebrates have a prominent ‘coronal’ suture that separates the front and back of the skull. This suture can develop entirely within mesoderm-derived tissue, neural crest-derived tissue, or at the boundary of the two. Recent paleontological findings and genetic insights in non-mammalian model organisms serve to revise fundamental knowledge on the development and evolution of this suture. Growing evidence supports a decoupling of the germ layer origins of the mesenchyme that forms the calvarial bones from inductive signaling that establishes discrete bone centers. Changes in these relationships facilitate skull evolution and may create susceptibility to disease. These concepts provide a general framework for approaching issues of homology in cases where germ layer origins have shifted during evolution.

Critical Importance of Entrepreneurship in Local Economic Development

2020 ◽  
pp. 1-34
Keyword(s):  
Sustainable Development ◽  
Economic Development ◽  
Rural Development ◽  
Local Economic Development ◽  
Developmental Change ◽  
Critical Importance ◽  
Rural Regions ◽  
Rural Economic Development ◽  
Strategic Options

In Chapter 1, the author considers the overall evolving ontological significance of entrepreneurship as a mindset in structural developmental change facilitating both local and rural economic development. Here it is illustrated that entrepreneurship itself is demanding new, non-divisive, non-mechanical developmental approaches to local economic development, in the sense that the current concepts which recognize this approach need to be fostered holistically in order to work well in modern economics. It is further conceived that both in local economic development and entrepreneurship, proposals based on indivisible developmental wholeness offer a much more effective way of approaching the general social-economic and rural reality. In subsequent chapters it will be further shown that rural regions can in fact greatly benefit from these notions. The author indicates that some regions are not able to attract investment and ensure sustainable development while regional and rural development agencies with entrepreneurial thinking offer many available strategic options.

Between Development and Evolution: How to Model Cultural Change

2002 ◽  
Author(s):  
Eva Jablonka
Keyword(s):  
Cultural Change ◽  
Cultural Evolution ◽  
General Framework ◽  
Genetic Model ◽  
Epigenetic Inheritance ◽  
Genetic System ◽  
Evolution And Development ◽  
The World ◽  
Somatic Selection ◽  
Development And Evolution

This chapter explores how the Darwinian model of evolution emerged as a major organising concept for explaining cultural change. It considers the application of the general framework of selection theory for thinking about cultural change and the evolution of other aspects of the world, but argues that the genic, neo-Darwinian model is inadequate for understanding cultural evolution. The chapter first discusses some of the properties of the genetic system and highlights the problems it poses for modelling cultural change, as well as some of the properties of the other inheritance systems known today (the epigenetic, the behavioural and the symbolic). It then suggests how changing the major assumptions of the classical genetic model gives rise to a view that denies a categorical distinction between evolution and development. It also argues that the classic neo-Darwinian assumptions about heredity and evolution must be abandoned in favour of more ‘Lamarckian’ genetic models that assign a central role to targeted genetic variation and somatic selection. Finally, it describes epigenetic inheritance systems, along with the transmission and selection of behavioural variants.

Material for a Synthesis

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Early Development ◽  
Evolutionary Theory ◽  
Environmental Influence ◽  
Phenotypic Flexibility ◽  
Immature Stages ◽  
Larval Stages ◽  
Key Concepts ◽  
Adaptive Radiations ◽  
Development And Evolution

The inconsistencies discussed in chapter 1 point toward two fundamental problems in need of solution: how to relate the environmental influence inherent in phenotype development to the genetic emphasis of evolutionary theory—Lewontin’s dilemma—and how to view the diverse phenomena of plasticity and development so as to illuminate evolutionary thinking in new ways—Wallace’s challenge. This chapter briefly describes some important, previously recognized connections among phenotypic flexibility, development, and evolution. It then defines key concepts for the chapters that follow. Important contributions toward a synthesis of development and evolution have accumulated over a period of many years. Some insights appear repeatedly in that cycle of inspiration and amnesia that characterizes important discoveries ahead of their times (for a concise review, see Hall, 1992, pp. 171-174). Some of these insights deal with the phenomenology of development and evolution—evidence that certain behavioral and developmental phenomena have influenced evolution in particular groups or in particular ways. These ideas, long familiar to evolutionary biologists, are the starting points for any attempt at a modern synthesis. Each of them will reappear again in later chapters. It does not require great sophistication in biology to realize that juveniles and adults have distinctive, divergent adaptations. Familiar extreme examples are the caterpillar and the butterfly, the tadpole and the frog. In such metamorphosing species, the juvenile has a dramatically different morphology, behavior, and ecology from that of the adult. Some hypermetamorphic insects show a striking series of differently specialized larval stages, and it is probably true of most organisms that juveniles and adults have different, evolved characteristics appropriate to their different niches, if for no other reason than the different requirements for dispersal, respiration, feeding, and defense that confront individuals of differing size (Schmidt-Nielsen, 1984; see also McKinney and McNamara, 1991). As a corrolary of this, different life stages evolve semi-independently. Thus, immature stages may evolve and diversify, undergoing their own adaptive radiations. Many authors have been impressed with the conservatism of certain aspects of early development.

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