What is Adaptation?

11 Key excerpts on "What is Adaptation?"

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  Physiology, Environment, and Man

  Based on a Symposium Conducted by the National Academy of Sciences–National Research Council, August, 1966

  • Douglas H. K. Lee, David Minard, Douglas H. K. Lee, David Minard(Authors)
  • 2013(Publication Date)
  • Academic Press

    (Publisher)

  Principles and General Concepts of Adaptation 1 C. LADD PROSSER Department of Physiofogy i? Biophysics, The University of Illinois, Urhana, Illinois My assignment in this conference is to present some of the principles of physiological adaptation from the viewpoint of a general biologist. First, I wish to present some definitions in the hope that this conference may agree on a common terminology. It is unfortunate that in many standard works; for example, the Handbook of Physiology (3, 5, 15, 18), certain words are used by different contributors with very different meanings. I hope to show that the general terminology developed by comparative physiologists is ap-plicable to human physiology. Further, while most of my examples will be drawn from temperature stresses, the terminology is equally applicable to such other environmental parameters as hypoxia, osmotic and ionic stresses, and nutritional factors. The word adaptation has many meanings and should be defined in each context in which it is used. If I were to ask 100 biologists for the meaning of adaptation, I might get 100 different definitions. It may well be that this word is no longer precise enough for serious usage. For some, adaptation refers to those properties (usually anatomic) which have been selected over long periods of evolution to permit survival. For others, adaptation refers to the rapid decay of an excitatory process, as in sensory adaptation. For still others, adaptation refers to any homeostatic reaction. In the present discussion, adapta-tion refers to any property of an organism which permits physiological activity and survival in a specific environment; adaptation is characteristically related to stressful components of the environment although it may relate equally well to a total environment. Adaptive characters have genetic basis but may be expressed according to environmental needs. A response is a direct reaction, either adaptive or nonadaptive to an environ-mental stimulus.

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  The Cambridge Companion to the Philosophy of Biology

  • David L. Hull, Michael Ruse(Authors)
  • 2007(Publication Date)
  • Cambridge University Press

    (Publisher)

  Similarly, ‘adaptation’ can refer either to the process by which organisms become well suited to their environments, or it can refer to the organic traits that are the end results of this process. Unless I stip- ulate otherwise, I will be talking about adaptation as a product in this essay. Broadly speaking, there are three quite different styles of definition of the adaptation concept. First, we could give a rough indication of what adaptation means by pointing to some of its instances – things like the eye, or the wing. Such definition by example, certainly when the examples are few, tells us little about how we should apply the concept. At this point, a second style of definition may appear. Adaptation is a concept used in modern biology, yet modern biolo- gists sometimes define the term in an informal way that echoes tim lewens 2 natural theology’s conception of organisms as designed objects. Williams gives just such a definition in the quotation we just saw: ‘An effect should not be called a function unless it is clearly pro- duced by design and not by chance’. This distinction between what an object’s effects are and what its functions are makes clear sense when we are talking about tools designed by agents. A screwdriver may be good at levering lids from paint tins, but that is not what the screwdriver is for – that is not its function – because the screwdriver was not designed to lift lids from paint tins. Williams’s definition expresses his view that adaptations are traits that are for something. For Williams, therefore, the question of whether some trait is an adaptation should depend on its design history. But Williams is no creationist: the design history in question is the evolutionary history of the trait. Williams’s comment explains why many biologists draw a dis- tinction between adaptive traits and adaptations.

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  Adaptive User Interfaces

  • Dermot Browne(Author)
  • 2016(Publication Date)
  • Academic Press

    (Publisher)

  Morphology defines the e n v i r o n m e n t s in which a species can survive. Physiology allows the organism to adjust to fluctuations in the e n v i r o n m e n t . A n d behaviour allows the organism to actively seek and transform aspects of the e n v i r o n m e n t into s o m e t h i n g biologically useful. T w o types of transformation are distinguished: those which rely on species-specific behaviour, and those which require the capacity to connect e x i s t i n g e l e m e n t s of behaviour with n e w s t i m u l u s e n v i r o n m e n t s (this is also referred to as psychological adaptation). T h e l a t t e r t r a n s f o r m a t i o n s e r v e s to w i d e n t h e r a n g e of e n v i r o n m e n t s w i t h i n w h i c h the i n d i v i d u a l can act. F u l l a n a n d Loubser (1972) describe the process as essentially a problem-solving a c t i v i t y i n w h i c h t h e i n d i v i d u a l e x a m i n e s t h e i r b e h a v i o u r a l repertoire to select the most appropriate response. T h i s is the type of activity w h i c h we e n v i s a g e d for the M o d e l l e r a n d I n t r o s p e c t o r p r o g r a m s . A n i n t e r e s t i n g p o i n t t h a t H e t t e m a n m a k e s a b o u t psychological adaptation is that it is an individual (or personality) c o n c e p t a n d n o t a s p e c i e s concept. It h a s s u r v i v a l v a l u e i n threatening, novel or c h a n g i n g environments and in more familiar e n v i r o n m e n t s it leads to an increase in flexibility and efficiency of behaviour. There are m a n y other biological comparisons that could be d r a w n but we will end this section with one taken from S t a d d o n ( 1 9 8 3 ) which nicely illustrates the increasing cost of m o v i n g up the levels of adaptivity. The pond animal Stentor h a s four different avoidance responses to a noxious substance: t u r n i n g a w a y , ciliary r e v e r s a l ,

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  Holistic Darwinism

  Synergy, Cybernetics, and the Bioeconomics of Evolution

  • Peter Corning(Author)
  • 2010(Publication Date)
  • University of Chicago Press

    (Publisher)

  Some soci-eties, in fact, seem to be systematically maladapted. 2 Accordingly, biological adaptation (and its antipode, maladaptation) are variables for humankind, just as they are for any other species. 3 Adaptation involves much more than simply “filling our bellies,” as one critic of an adaptationist paradigm charged, and even in affluent Western societies the provision of adequate food and shelter are problematical for a significant number of people (Riches 1997). But more to the point, the problem of meeting basic survival and reproductive needs is an imperative for every one of us, whether or not we are aware of it, or care about it. In Biological Adaptation in Human Societies 257 fact, our biological needs routinely impose themselves on the daily rhythms of our lives. And if our basic needs are not met, there will be significant biological/adaptive consequences, not to mention psychological pertur-bations. What the value-relativists often overlook is the fact that survival and reproduction are inescapable daily imperatives for all of us. We must actively pursue the meeting of our survival and reproductive needs or we will fail to do so, with predictable consequences. In this light, an economic science that is focused exclusively on the psychology of human preferences and satisfactions, and is studiously indifferent to the bio-logic of adapta-tion, excludes by fiat a bedrock source of psychological motivation and causation in economic life. The Problem of Measuring Adaptation The core analytical challenge, then, is how do we measure adaptation? The ultimate biological criterion of adaptation is Darwinian “fitness”. Traditionally, this has been defined as the ability of an individual to produce viable progeny, or of an interbreeding population to reproduce itself.

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  Not by Design

  Retiring Darwin’s Watchmaker

  • John Reiss(Author)
  • 2009(Publication Date)
  • University of California Press

    (Publisher)

  However, given the difficulties with precisely defining natural selection (in the narrow sense) detailed in the previous part of this book, it seems foolish to connect the process of adaptation with natural selection by definition. What I really want to ask, of course, is how to connect the process with natural selection in the broad sense—namely, with the conditions for existence. From the perspective of the conditions for existence, the process of adaptation can only mean a change in lifestyle or mode of adaptedness, since overall adaptedness (rate of increase) does not generally increase in evolution. Thus, adaptation as a process generally refers only to changes in the adaptedness of individual features of organisms, not changes in the adaptedness of the organisms themselves. In parallel with the two ways of looking at the adaptedness of specific features, adaptation with respect to those features might mean one of two things. First, it might indicate relative improvement in the effect of the feature on organismal survival (and reproduction), compared with what would obtain if the ancestral form was retained. It is often assumed as a corollary that the derived state of the feature would do less well than the ancestral one in the old environment/lifestyle. Second, adaptation might mean improved performance of the feature at some particular task that is critical for survival of the organism in the new lifestyle/environment, compared with the ancestral (plesiomorphic) form. Thus, for example, in a lizard population that changes evolutionarily from one in which most of the individuals spend most of their time on relatively hard substrates, to one in which most lizards spend most of their time in sandy washes, adaptation as a process means an integrated change in the environment (little sand lots of sand) and lifestyle (not running on sand often doing so), of which the change in form of foot is one necessary condition (in the conditional teleological sense).

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  Evolution

  • Mark Ridley(Author)
  • 2009(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  The woodpecker is more likely to survive, in its natural habitat, by possessing them. Camouflage is another, particularly clear, example of adaptation. Camouflaged spe- cies have color patterns and details of shape and behavior that make them less visible in their natural environment. Camouflage assists the organism to survive by making it less visible to its natural enemies. Camouflage is adaptive. Adaptation, however, is not an isolated concept referring to only a few special properties of living things a it applies to almost any part of the body. In humans, hands are adapted for grasping, eyes for seeing, the alimentary canal for digesting food, legs for movement: all these functions assist us to survive. Although most of the obvious things we notice are adaptive, not every detail of an organism’s form and behavior is necessarily adaptive (Chapter 10). Adaptations are, however, so common that they have to be explained. Darwin regarded adaptation as the key problem that any theory of evolution had to solve. In Darwin’s theory a as in modern evolutionary biology a the problem is solved by natural selection. Natural selection means that some kinds of individual in a population tend to contrib- ute more offspring to the next generation than do others. Provided that the offspring resemble their parents, any attribute of an organism causing it to leave more offspring than average will increase in frequency in the population over time. The composition of the population will then change automatically. Such is the simple, but immensely powerful, idea whose ramifying consequences we shall be exploring in this book. 1.3 A short history of evolutionary biology We shall begin with a brief sketch of the historic rise of evolutionary biology, in four main stages: 1. Evolutionary and non-evolutionary ideas before Darwin. 2. Darwin’s theory (1859). 3. The eclipse of Darwin (c. 1880 –1920).

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  Human Adaptation

  • Howard Morphy, G. A. Harrison(Authors)
  • 2020(Publication Date)
  • Routledge

    (Publisher)

  Indeed, there is no biological reason why it should be: evolutionary biology merely claims that organisms’ behaviour will, if left to itself, tend towards increased adaptiveness. Degrees of adaptiveness are inevitable since evolution is a dynamic process and the biological world thus undergoes constant change: that, after all, is why species eventually go extinct! In addition, however, there is a branch of evolutionary theory that concerns itself with the evolutionary behaviour of traits under conditions of neutral selection when there is no direct selection pressure that leads to adaptation (see Maynard Smith 1989). For present purposes, however, I merely note this fact. The problem of measuring adaptation When we speak of adaptation in an evolutionary context, we mean to suggest that a particular trait confers a selective advantage—in other words, that a given trait allows its possessor to contribute more copies of a given gene to the next generation than any alternative trait of the same kind. This is the benchmark against which evolutionary biologists judge a trait’s adaptiveness. However, it is important to remember that this is not the end of the matter as far as evolutionary explanations go. To assert that a trait contributes to the propagation of genes in future generations is to say no more than that those genes that survive are the ones that survive best, the classic ‘evolutionary tautology’ (see Dunbar 1982, and references therein). Darwinian explanations should offer us more than this: they should tell us why some genes are propagated more effectively than others. This part of the classic Darwinian formula is concerned with adaptation

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  The Plausibility of Life

  Resolving Darwin's Dilemma

  • Marc W. Kirschner, John C. Gerhart(Authors)
  • 2020(Publication Date)
  • Yale University Press

    (Publisher)

  T  H  R  E  E Physiological Adaptability and Evolution

  Evolution, as we have seen, is framed by two features: conservation on a cellular level and diversity on an anatomical and physiological level. How does diversification occur despite so much conservation? In this chapter we examine a few examples that reveal how conservation actually enables variation. The connection between the two is at the level of mechanisms; those that are exploited for evolution are the very ones that the organism uses day to day to vary its phenotype to meet new physiological demands. Such mechanisms can be easily modified in evolution to yield new phenotypes.

  The potential relationship between physiological variation and evolutionary variation had been considered by some evolutionary biologists in the premolecular era, without wide acceptance. It is on the molecular level that the link between the two is seen most distinctly and where the evidence for facilitated variation is most persuasive.

  Physiological Variation and Evolution

  In the nineteenth century, scientists and philosophers struggled to settle the issue of whether the organism could pass its somatic adaptation, its so-called acquired characteristics, to the next generation. As attractive as that idea was to Lamarck and even to Darwin, it was decisively nullified both experimentally and mechanistically. Somatic adaptations include the physiological, behavioral, anatomical, and developmental changes that take place within a generation, are made in response to environmental changes, and are directed to the organism’s immediate benefit. They are often reversed as the environmental challenge subsides. Evolutionary adaptations, on the other hand, are heritable changes of physiology, behavior, anatomy, or development to the organism’s immediate benefit, transmitted over many generations and lasting even when the environmental challenge is gone. Although sometimes occurring under similar environmental conditions, somatic and evolutionary change seem very different from each other, and there is no known mechanistic path from one to the other.

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  Evolution and Escalation

  An Ecological History of Life

  • Geerat J. Vermeij, Geerat Vermeij(Authors)
  • 2021(Publication Date)
  • Princeton University Press

    (Publisher)

  4. The effectiveness of an individual in coping with a hazard is the probability that the individual survives or prevails when it encoun-ters or becomes aware of the hazard. Effectiveness of reproduction is defined as the probability that an individual leaves at least one off-spring in the next generation, or as the number of offspring left by the individual in the next generation. 5. Because organisms generally are not perfectly adapted to their surroundings, the potential for further adaptation is nearly always present. This potential depends on the number of individuals that are exposed to a given hazard, the effectiveness of individuals in coping with the hazard, and the probability that a given individual possesses a mutation enabling that individual to increase its effectiveness. 6. Adaptive improvement takes place when the effectiveness of in-dividuals increases, that is, when the adaptive gap between an indi-vidual's capacity to withstand a challenge and some absolute meas-ure of the severity of hazards narrows. Escalation occurs when the frequency and severity of hazards increase, and when aptations to these hazards become better expressed. 7. Because the potential for selection in favor of existing or en-hanced aptations declines as the adaptive gap widens, adaptation to increasingly severe hazards should be less common than are ecolog-ical restriction and extinction. 8. Biological agencies—competition and predation in the broad sense—are the primary agencies of selection for the vast majority of species. Selection in favor of the acquisition and retention of re-sources affects all species. Most species have predators, and most predators are incapable of killing all the prey they encounter, chase, or subdue. Weather and food are of secondary selective importance.

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  Biology for Engineers, Second Edition

  • Arthur T. Johnson(Author)
  • 2018(Publication Date)
  • CRC Press

    (Publisher)

  9. Birds will migrate south in the winter unless they can meet their needs in the north. 10. Worms are forced to the surface during a heavy rain. 11. Predators go where the prey are, not vice versa. 12. If you feed a stray cat once, it will probably return. 406 Biology for Engineers temperature, availability of food and water, light, and competition. The difference is that those BU that adapt best to new environments are also those that are expected to be more successful at reproduction. Over the course of many generations, the genes from those BU that demonstrate better harmony with their environments will predominate. It was shown previously that adaptations require extra energy and resources that could otherwise be used for growth and reproduction, thus reducing growth and reproduction. Adaptation, as a term used in this book, is meant to mean a nonpermanent, non-genetic, change in a BU. Before the discovery of epigenetic gene silencing, it was easy to distinguish between adaptation and evolution. The latter involved a change in the genetic code whereas the former did not. However, epigenetic changes can persist for many generations without a fundamental genetic change. Therefore, the feature most distinguishing between adaptation and evolution must then be that adaptation reduces growth and reproduction, whereas evolution leads to BU more successful at growth and reproduction. For evolution to occur, there must be 1. Pre-existing genetic variation or some means for genetic changes (mutations) to occur 2. An environmental condition that remains over the course of many generations 3. A differential reproductive advantage of the responses of some genes compared to others With no variation, there would be no competition allowing eventual genetic dominance; all genes would be alike, and all would be equally as suited (or not) to prevailing environ-mental conditions.

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  The Princeton Guide to Evolution

  • David A. Baum, Douglas J. Futuyma, Hopi E. Hoekstra, Richard E. Lenski, Allen J. Moore, Catherine L. Peichel, Dolph Schluter, Michael C. Whitlock, David A. Baum, Douglas J. Futuyma, Hopi E. Hoekstra, Richard E. Lenski, Allen J. Moore, Catherine L. Peichel, Dolph Schluter, Michael C. Whitlock(Authors)
  • 2013(Publication Date)
  • Princeton University Press

    (Publisher)

  Garland, T., and P. A. Carter. 1994. Evolutionary physiology. Annual Review of Physiology 56: 579–621. Hochachka, P. W., and G. N. Somero. 2002. Biochemical Adaptation. Oxford: Oxford University Press. Karasov, W. H., and C. Martínez del Rio. 2007. Physiological Ecology: How Animals Process Energy, Nutrients, and Toxins. Princeton, NJ: Princeton University Press. McNab, B. K. 2002. The Physiological Ecology of Vertebrates: A View from Energetics. Ithaca, NY: Cornell University Press. Natochin, Y. V., and T. V. Chernigovskaya. 1997. Evolutionary physiology: History, principles. Comparative Biochemistry and Physiology A 118: 63–79. Passage contains an image III.14 Evolution of the Ecological Niche Robert D. Holt

  OUTLINE

  1.  Natural history, niches, and evolution 2.  What is an ecological “niche”? 3.  Complexities in the niche concept 4.  The issue of genetic variation in niches 5.  Demographic constraints on niche evolution 6.  Niches evolving in communities

  Every species and clade has a niche characterizing the range of environments (including abiotic as well as biotic factors) within which it persists, and outside of which it goes extinct. The niche describes how an organism with a particular phenotype performs in its demography (birth and death rates) as a function of environmental conditions. Given genetic variation in these traits, niches can evolve, sometimes quite rapidly, but niches also can show surprising conservatism. To understand niche evolution, one must draw on and integrate many areas of knowledge, ranging from detailed mechanistic understanding of individual performance to the mapping of genes to phenotypes, from life histories, mating systems, and population dynamics to population genetics, community ecology, and the broad spatial and historical perspectives of landscape ecology, biogeography, and paleobiology. Understanding niche evolution and conservatism is important to many basic questions in evolution, ecology, and biogeography, and it is also highly germane to many crucial applied issues.

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