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Topic: Ecological selection

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  Ecological selection - Wikipedia, the free encyclopedia
Ecological selection (or environmental selection or survival selection or individual selection or asexual selection) refers to natural selection minus sexual selection, i.e.
Ecological selection can be said to be taking place in any circumstance where inheritance of specific traits is determined by ecology alone without direct sexual competition, when e.g.
In general, ecological selection is assumed to be the dominant process in natural selection, except in highly cognitive species that do not, or do not always, pair bond, e.g.
en.wikipedia.org /wiki/Ecological_selection   (959 words)

 Natural selection - Wikipedia, the free encyclopedia
Natural selection is a process by which biological populations are altered over time, as a result of the propagation of heritable traits that affect the capacity of individual organisms to survive and reproduce.
Natural selection is distinguished from artificial selection, which is the alteration of domesticated species resulting from human intervention as opposed to the "natural environment".
Natural selection does not distinguish between ecological selection and sexual selection, as it is concerned with traits, for example, dexterity of movement, on which both may operate simultaneously.
en.wikipedia.org /wiki/Natural_selection   (1575 words)

 Ecological selection -- Facts, Info, and Encyclopedia article   (Site not responding. Last check: 2007-11-07)
Ecological selection (or environmental selection or survival selection or individual selection or asexual selection) refers to (A natural process resulting in the evolution of organisms best adapted to the environment) natural selection minus (Click link for more info and facts about sexual selection) sexual selection, i.e.
In cases where ecological and sexual selection factors are strongly at odds, simultaneously encouraging and discouraging the same traits, it may also be important to distinguish them as sub-processes within (A natural process resulting in the evolution of organisms best adapted to the environment) natural selection.
In general, ecological selection is assumed to be the dominant process in (A natural process resulting in the evolution of organisms best adapted to the environment) natural selection, except in highly cognitive species that do not, or do not always, pair bond, e.g.
www.absoluteastronomy.com /encyclopedia/E/Ec/Ecological_selection.htm   (914 words)

 Evolutionary Genetics
Ecological genetics is the study of evolutionary processes, especially adaptation by natural selection, in an ecological context in order to account for phenotypic patterns observed in nature.
Ecological genetics began at a time when the major theoretical aspects of the Modern Synthesis were in place, when the marvels of adaptation were clear, but when few empirical examples of natural selection in action were available.
To the extent that novel selection results from a change of environment and begins to act on existing or standing variation already in the population, the impact on neutral polymorphisms may be quite minimal.
plato.stanford.edu /entries/evolutionary-genetics   (6345 words)

 The role of mate choice in biocomputation:
Sexual selection through mate choice (Darwin, 1871) has traditionally been considered a minor, peripheral, even pathological process, tangential to the main work of natural selection and largely irrelevant to such central issues in biology as speciation, the origin of evolutionary innovations, and the optimization of complex adaptations (see Cronin, 1991).
By contrast, sexual selection often results in an unpredictable, divergent pattern of evolution, with lineages speciating spontaneously and exploring the space of phenotypic possibilities according to their capriciously evolved mate preferences.
If one visualizes sexual selection dynamics as branching, divergent patterns that explore phenotype space capriciously and autonomously, and natural selection dynamics as convergent, hill-climbing patterns that seek out adaptive peaks, then their potential complementarity can be understood.
www.unm.edu /~psych/faculty/biocomputation.htm   (12157 words)

 Sexual_selection   (Site not responding. Last check: 2007-11-07)
Sexual selection is the theory that competition for mates between individuals of the same sex (typically males) drives the evolution of certain traits.
It is distinct from ecological selection which is the competition for food within the species' ecological niche.
Because traits held to be due to sexual selection often conflict with the survival fitness of the individual, the question then arises as to why, in nature, in which survival of the fittest is considered the rule of thumb, such apparent liabilities are allowed to persist.
www.freecaviar.com /search.php?title=Sexual_selection   (1448 words)

 Natural selection - FreeEncyclopedia   (Site not responding. Last check: 2007-11-07)
Natural selection is an essential mechanism of evolution proposed by Charles Darwin and generally accepted by the scientific community as the best explanation of speciation as evidenced in the fossil record.
Natural selection does not distinguish between ecological selection and sexual selection, as it is concerned with traits, e.g.
In addition, many theories of Artificial selection have been proposed to suggest that economic or social fitness factors assessed by other humans or their built environments are somehow biological or inevitable - Social Darwinism.
openproxy.ath.cx /na/Natural_selection.html   (863 words)

 Biological Complexity - Evolutionary Tree of Life
The historical record of the genetic changes that have taken place during the last four billion years is rather like a web, especially because of occasional "horizontal gene transfer" between species, but it is often presented as a tree or star diagram.
The ecological context of that original change, affected by all of the constellations of genes in other organisms and the way they interact, is probably more important.
Selective breeding, practised by humans for millennia, is a manipulation of the first set of processes.
www.phy.auckland.ac.nz /staff/prw/biocomplexity/evolutionary_tree.htm   (382 words)

 Price equation - Wikipedia, the free encyclopedia
Now suppose that the population reproduces, all parents are eliminated, and then there is a selection process on the children, by which less fit children are removed from the reproducing population.
This may explain the redundancy in the genetic code, in which some amino acids are encoded by more than one codon in the DNA.
Although the codons produce the same amino acids, they have an effect on the mutability of the DNA, which may be selected for or against under certain conditions.
www.wikipedia.org /wiki/Price_equation   (2524 words)

 Ecological selection   (Site not responding. Last check: 2007-11-07)
Ecological selection (or environmental selection or survival selection or individual selection or asexual selection) refers to natural selection minus sexual selection, i.
However it is clearly observed in other species, it seems unreasonable to differentiate colonization by ship from colonization by walking, and even the word "colony" isn't specific to humans but refers generically to an intrusion of one species on an ecology to which it has not wholly adapted.
Some would call this too artificial selection, not natural or ecological, as the radiation doesn't enter the ecology as a factor save due to man's effort.
www.termsdefined.net /ec/ecological-selection.html   (1005 words)

 Evolution II
SPECIATION BY NATURAL SELECTION Dobzhansky (1936) and Muller (1939) introduced a two- locus model that may be generalized to multiple loci or to multiple alleles at one locus Ancestral population is A2A2 B2B2 Insert Fig.
Ecological specialization Persistence of newly formed species is favored by ecological opportunities (vacant niches) 5.
Ecological isolation and adaptation - Evolution of ecotypes or subspecies associated with different habitats 4.
eebweb.arizona.edu /Courses/Ecol435_535/Oct21.htm   (914 words)

Here selection is modeled as a process of trial and error by communities of farmers over a period of centuries, in which it is assumed that they prefer cropping patterns that increase their rice harvests.
Levin considers this an example of frequency-dependent selection, but we suggest that it is better characterized as system-dependent selection, since the frequency of one of the phenotypes (the resistant strain) influences the environment in ways that affect the fitness of both phenotypes.
Levin, B.R. (1988) "Frequency-dependent selection in bacterial populations".
www.ic.arizona.edu /~lansing/System-dep_selection.htm   (7990 words)

 Biology524.Lectures2   (Site not responding. Last check: 2007-11-07)
Selection and drift are the main engines of evolutionary change.
Evolution via selection is an inevitable outcome in a self-replicating system displaying 4 properties recognized by Darwin (1859).
Selective change relies on the interaction of introduction and sorting processes in an iterative manner.
bioweb.wku.edu /faculty/McElroy/BIOL524/524lects2.htm   (194 words)

 Alex Badyaev - research   (Site not responding. Last check: 2007-11-07)
Extensive interspecific diversity in sexual dimorphism is assumed to follow from variation in intensity of sexual selection, which in turn, is strongly affected by ecological conditions.
However, because current expression of dimorphism is a result of not only of current selection, but also of ancestral condition, phylogeny must play a central role in attempts to understand the evolution of sexual dichromatism.
Where selection appear to have played a role in the evolution of sexual dichromatism, a phylogenetic perspective may allow to distinguish between evolutionary constraints and forces such as sexual selection.
www.u.arizona.edu /~abadyaev/res2.html   (1277 words)

 Current Research: The Detection of the Long-term Outcome of Natural Selection and the Ecological Sorting of Species ...
One way to examine the long-term role of natural selection in molding plant reproductive characters is to use a comparative approach.
These methods are non-experimental in nature, but they have been extremely successful in elucidating the ecological importance of life history and reproductive characters in plants and animals.
Ecological adaptation, gene flow, and the potential for hybrid breakdown in restoration projects.
www.lifesci.ucsb.edu /eemb/faculty/mazer/research/research_05.html   (953 words)

 Ecological Monographs : Natural selection and ecotypic differentiation in Impatiens pallida. @ HighBeam Research   (Site not responding. Last check: 2007-11-07)
Ecological Monographs : Natural selection and ecotypic differentiation in Impatiens pallida.
Start / E / Ecological Monographs / August 01, 1995 / Natural selection and ecotypic differentiation in Impatiens pallida.
Ecological Monographs; August 01, 1995; Bennington, Cynthia C. McGraw, James B. Read the Full Article, Get a FREE Trial for instant access »
static.highbeam.com /e/ecologicalmonographs/august011995/naturalselectionandecotypicdifferentiationinimpati/index.html   (222 words)

The emphasis, in their eyes, lies in the relative importance of ecological selective forces over the stochastic forces of drift and mutation (rather than an emphasis on allopatric vs. parapatric vs. sympatric).
Fisher (1958) felt that natural selection played a large role and that it did so in the context of large populations in which drift played a negligible role but rare advantageous alleles could spread by "mass selection".
Moving to higher peaks might be difficult and might require interdemic selection, migration between demes, periods of drift that could move populations across adaptive valleys towards higher peaks.
www.uwyo.edu /dbmcd/molmark/lect2a.html   (2986 words)

 ENHS Nature Trails October 2000 Article 2   (Site not responding. Last check: 2007-11-07)
Nearly 150 years ago Charles Darwin observed that sexual dimorphic characteristics are likely to be the result of sexual selection, fecundity selection, or ecological causes.
Fecundity selection explains other sexually dimorphic species, as in the case of the increased size of the female pray mantis, who is half again as long as her mate due to the large mass of eggs she carries.
Ecological explanations for sexual dimorphic characteristics have been notoriously problematic because most species use the same environmental resources for feeding, sleeping and other day-to-day activities.
biology.uoregon.edu:16080 /enhs/archive/oct00/oct002.html   (618 words)

 Abstract   (Site not responding. Last check: 2007-11-07)
Body size can influence an organism’s microevolutionary fitness either via ecological factors (ecological selection) or changes in reproductive output (sexual or fecundity selection).
Published studies on sexual dimorphism in reptiles have generally focussed on sexual-selective forces on males, under the implicit assumption that the intensity of fecundity selection in females (and hence, overall selection on female body size) is likely to be relatively consistent among lineages.
These results suggest that variation in female body size among and within species (and hence, in the degree of sexual dimorphism) may be driven by the ecological as well as reproductive consequences of body size variation in both sexes.
www.oikos.ekol.lu.se /Oikos.89.3.abstracts/10259bonnet.htm   (239 words)

 Ecological Selection Encyclopedia Article, Definition, History, Biography   (Site not responding. Last check: 2007-11-07)
Looking For ecological selection - Find ecological selection and more at Lycos Search.
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www.karr.net /encyclopedia/Ecological_selection   (1104 words)

 Ecology and Strategy
The dominant logic in organizational ecology in contrast, emphasizes adaptation through environmental selection at the population or industry level, rather than by individual organizations.
ecological models of resource partitioning and the evolution of new market segments and strategic models of industry consolidation and threats of new entry.
This volume thus seeks to bring strategic and ecological perspectives closer together to join forces for further theory development in areas of mutual interest.
www.mgmt.utoronto.ca /~baum/v23_toc.html   (565 words)

 Inaugural Article: Evolution of genome-phenome diversity under environmental stress -- Nevo 98 (11): 6233 -- ...
selection is indeed the mechanism underlying the genetic and organismal
Strong selection (more than 10% per trait) may be a common phenomenon in nature, as first emphasized by Ford (4).
and biotic selection for multilocus quantitative traits (71),
www.pnas.org /cgi/content/full/98/11/6233   (6240 words)

 [No title]
Not recognized by topics investigated, but by the way ecological problems are conceived and analyzed using ecological, genetic and evolutionary principles.
Strength with which natural selection was expected to act at various levels of biological organization (V.C. Wynne-Edwards, 1962; G.C. Williams, 1966).
Darwin, C. On the origin of species by means of natural selection or the preservation of favored races in the struggle for life.
www.life.uiuc.edu /ib/443/lectures/EvolHis.doc   (298 words)

 Natural selection and speciation -- Schneider 97 (23): 12398 -- Proceedings of the National Academy of Sciences
Natural selection has always been considered a key component of adaptive divergence and speciation (2, 15-17), but the importance
If selection is driving population divergence, then, for a given level of genetic divergence, greater reproductive isolation (or morphological divergence) is expected among populations from different habitats than among populations occupying similar habitats.
If reproductive divergence is greater between A and B (and A' and B') than between A and A' (and B and B'), then selection is implicated in divergence.
www.pnas.org /cgi/content/full/97/23/12398   (1579 words)

 Ecology: Countergradient Selection For Rapid Growth In Pumpkinseed Sunfish: Disentangling Ecological And Evolutionary ...
However, under some circumstances the evolutionary response to a gradient may be opposite of the ecological response, a phenomenon known as "countergradient variation." We had previously predicted that countergradient selection has occurred in pumpkinseed sunfish in response to a resource gradient created by competition with bluegill sunfish.
By contrast, Arendt and Wilson (1997) identified a situation in which low resource levels could select for a rapid intrinsic growth rate, provided there is a size-determined niche shift from a low-resource niche to a high-resource niche.
If countergradient selection for rapid growth has occurred in this system, pumpkinseed growth rates should decrease as bluegill density increases (the ecological effect), but sympatric pump kinseed should grow faster than allopatric pumpkinseed under all conditions (the evolutionary effect).
www.findarticles.com /cf_dls/m2120/8_80/58517889/p1/article.jhtml   (1352 words)

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