Fitness Consequences of Outcrossing in Impatiens capensis: Tests of the Frequency-Dependent and Sib-Competition Models

Evolution ◽  
1989 ◽  
Vol 43 (5) ◽  
pp. 1075 ◽  
Author(s):  
Claire McCall ◽  
Thomas Mitchell-Olds ◽  
Donald M. Waller
Keyword(s):  
Impatiens Capensis ◽  
Frequency Dependent ◽  
Competition Models ◽  
Fitness Consequences

Frequency-Dependent Fitness Consequences of Intraspecific Nest Parasitism in Snow Geese

Evolution ◽  
1990 ◽  
Vol 44 (6) ◽  
pp. 1436 ◽  
Author(s):  
David B. Lank ◽  
Robert F. Rockwell ◽  
Fred Cooke
Keyword(s):  
Nest Parasitism ◽  
Frequency Dependent ◽  
Snow Geese ◽  
Fitness Consequences ◽  
Intraspecific Nest Parasitism

Frequency-dependent selection and competition: empirical approaches

1988 ◽  
Vol 319 (1196) ◽  
pp. 601-613 ◽  
Keyword(s):  
Natural Selection ◽  
Competitive Interactions ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Theory Of Evolution ◽  
Competitive Outcome ◽  
Competition Models ◽  
Evolution By Natural Selection ◽  
Survival Of The Fittest ◽  
Empirical Approaches

When Darwin and Wallace first formulated the theory of evolution by natural selection, they were greatly influenced by the idea that populations tend to increase geometrically and rapidly outgrow the resources available to them. They argued that the ensuing competition among individuals would be a major agent of natural selection. Since their day, competition has become almost synonymous with the idea of natural selection or survival of the fittest. In this paper we examine the relation between competition and selection by using simple competition models, consider the interaction of density and frequency in determining competitive outcome, and review the literature on frequency-dependent competitive interactions among genotypes within populations.

Dealing with hot rocky environments: Critical thermal maxima and locomotor performance in Leptodactylus lithonaetes (Anura: Leptodactylidae)

2019 ◽  
pp. 155-161 ◽  
Author(s):  
Ivan Beltran
Keyword(s):  
Environmental Temperature ◽  
Extreme Temperature ◽  
Effect Of Temperature ◽  
Maximum Speed ◽  
Locomotor Performance ◽  
Extreme Temperatures ◽  
Physiological Limits ◽  
Fitness Consequences ◽  
Thermal Maximum ◽  
Environmental Temperatures

Environmental temperature has fitness consequences on ectotherm development, ecology and behaviour. Amphibians are especially vulnerable because thermoregulation often trades with appropriate water balance. Although substantial research has evaluated the effect of temperature in amphibian locomotion and physiological limits, there is little information about amphibians living under extreme temperature conditions. Leptodactylus lithonaetes is a frog allegedly specialised to forage and breed on dark granitic outcrops and associated puddles, which reach environmental temperatures well above 40 ˚C. Adults can select thermally favourable microhabitats during the day while tadpoles are constrained to rock puddles and associated temperature fluctuations; we thus established microhabitat temperatures and tested whether the critical thermal maximum (CTmax) of L. lithonaetes is higher in tadpoles compared to adults. In addition, we evaluated the effect of water temperature on locomotor performance of tadpoles. Contrary to our expectations, puddle temperatures were comparable and even lower than those temperatures measured in the microhabitats used by adults in the daytime. Nonetheless, the CTmax was 42.3 ˚C for tadpoles and 39.7 ˚C for adults. Regarding locomotor performance, maximum speed and maximum distance travelled by tadpoles peaked around 34 ˚C, approximately 1 ˚C below the maximum puddle temperatures registered in the puddles. In conclusion, L. lithonaetes tadpoles have a higher CTmax compared to adults, suggesting a longer exposure to extreme temperatures that lead to maintain their physiological performance at high temperatures. We suggest that these conditions are adaptations to face the strong selection forces driven by this granitic habitat.

Preceding Stimulus Frequency-Dependent Potentiation of the Postrest Shortening of the Action Potential Duration in Rabbits.

2000 ◽  
Vol 41 (4) ◽  
pp. 481-492
Author(s):  
Naohiko Takahashi ◽  
Morio Ito ◽  
Shuji Ishida ◽  
Takao Fujino ◽  
Mikiko Nakagawa ◽  
...  
Keyword(s):  
Action Potential ◽  
Action Potential Duration ◽  
Stimulus Frequency ◽  
Frequency Dependent ◽  
Preceding Stimulus
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