Response to Environment

3 Key excerpts on "Response to Environment"

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  Autecology

  Organisms, Interactions and Environmental Dynamics

  • Gimme H. Walter, Rob Hengeveld(Authors)
  • 2014(Publication Date)
  • CRC Press

    (Publisher)

  The unpredictability of weather conditions and climatic changes, both temporally and spatially (e.g., Mathieu et al. 2004, Rodwell et al. 2004, Sutton and Hodson 2005, Sutton et al. 2005, van Oldenborgh 2005), are obstacles to anticipating environmental conditions elsewhere or in the future. All of the above factors and influences operate directly through the environmental response systems of individual organisms and need consideration when survival probabilities are measured and estimates of reproductive output are made with respect to locality, environment and environmental dynamics. Environmental Response Systems of Organisms—Co-determinants of .... 179 Many types of environmentally relevant mechanisms of organisms are fairly well understood in ecophysiological, ecomorphological, and ethological terms (see Gould 1982a, Schmidt-Nielsen 1990, Alexander 1999, Burkhardt 2005, Moyes and Schulte 2006). However, many remain poorly understood. Perhaps the most significant of these to autecological understanding are ones that involve sensory processing and the movement of organisms (Dusenbery 1992). As an example, the polyphagous thrips Frankliniella schultzei uses multiple host species, but its abundance varies across plants of different species, with most individuals and the highest rates of reproduction being associated with the primary host species in the local study area (Milne and Walter 2000). But why individuals of this species are associated with host species other than the primary host has yet to be determined.

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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)

  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. It is usually, but not necessarily, reversible. An example would be a direct change in rate of a chemical reaction with temperature, as in a Qio effect. Adaptive variations may be measured in individuals, populations, or higher taxonomic categories. They include anatomic, physiologic, and biochemical characteristics of individual organisms which relate these individuals adaptively to a specific environment. In an evolutionary sense, only those variations that are adaptive are retained. Natural selection is the only known mechanism for fixation of adaptive varia-tions and forms the basis for speciation. 1 Research on which this paper is based was aided by NSF Grant GB4005. 88 PRINCIPLES AND CONCEPTS OF ADAPTATION 89 A physiological concept of biological species may be derived as follows: If no two species can occupy the same ecological niche or the same geographic range throughout their life cycles, it follows that every species must be uniquely adapted to its particular niche and range. Hence, if we could quantitatively describe the physiological adaptedness of a species to its ecological niche and geographic range, we would have a truly meaningful description of the species. One of the goals of environmental physiology is to achieve some understanding of the molecular basis for natural selection. However in the context of this conference adaptive variations are con-sidered for individuals, not species. Homeostasis is a term which has been broadened from the original meaning of Cannon to refer to self-stabilizing states or organisms, societies, and com-puters.

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  Biology for Engineers, Second Edition

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

    (Publisher)

  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. Fortunately, there is genetic variation. Environmental conditions can interact with individual genes to influence whether or not they become active. In this way, the environment can directly influence the development of a BU. Thus, individual cells differentiate into specialized cells, whole organisms acquire individual traits, and ecological systems include mixes of flora and fauna best suited to the exploitation of their environs. SPECIES FORMATION At some point, when portions of a population are isolated from one another, their genetic codes begin to diverge due to mutations and natural selection, allowing them to survive and reproduce better in their individual environmental conditions. There are two theories about the emergence of a new species. The first is that two species diverge from a common ancestor; the second is that a new species emerges as gradual changes take place in a previous species, making the evolved species significantly different from its previous form. In both cases, the new species would not be able to reproduce with other species. Barriers that isolate a population and lead to a new species formation (Shermer, 2010; Reisch, 2016) are: 1. Geographic (such as a mountain range, desert, ocean, or river) 2. Morphological (changes in coloration, body type, or reproductive organs) 3. Behavioral (a change in breeding season, mating calls, or courtship actions) 407 Biological Responses in Context Environmental factors may allow an individual to acquire particular traits, but, unless these are able to change the genetic code, they cannot be passed directly to subsequent generations.

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