scholarly journals Community-level natural selection modes: A quadratic framework to link multiple functional traits with competitive ability

2018 ◽  
Vol 107 (3) ◽  
pp. 1457-1468 ◽  
Author(s):  
Andrés G. Rolhauser ◽  
Marisa Nordenstahl ◽  
Martín R. Aguiar ◽  
Eduardo Pucheta
Keyword(s):  
Natural Selection ◽  
Functional Traits ◽  
Competitive Ability ◽  
Community Level

The relationship between facial whorl direction and sidedness in ridden horses

2006 ◽  
Vol 35 ◽  
pp. 247-250
Author(s):  
H. Randle ◽  
E. Elworthy
Keyword(s):  
Natural Selection ◽  
Artificial Selection ◽  
Competitive Ability ◽  
Close Association ◽  
Human Behaviour ◽  
Physical Ability ◽  
Facial Hair ◽  
Selection For ◽  
The Relationship ◽  
The Brain

The influence of Natural Selection on the evolution of the horse (Equus callabus) is minimal due to its close association with humans. Instead Artificial Selection is commonly imposed through selection for features such as a ‘breed standard’ or competitive ability. It has long been considered to be useful if indicators of characteristics such as physical ability could be identified. Kidd (1902) suggested that the hair coverings of animals were closely related to their lifestyle, whether they were active or passive. In 1973 Smith and Gong concluded that hair whorl (trichloglyph) pattern and human behaviour is linked since hair patterning is determined at the same time as the brain develops in the foetus. More recently Grandin et al. (1995), Randle (1998) and Lanier et al. (2001) linked features of facial hair whorls to behaviour and production in cattle. Hair whorl features have also been related to temperament in equines (Randle et al., 2003).

Natural selection and adaptation

2018 ◽  
Author(s):  
Tim Lewens
Keyword(s):  
Natural Selection ◽  
Functional Traits ◽  
Evolutionary Biology ◽  
Skin Pigmentation ◽  
Essential Element ◽  
Natural World ◽  
Modern Biology ◽  
Biology Textbook ◽  
Selection For ◽  
The Relationship

Students of the natural world have long remarked on the fact that animals and plants are well suited to the demands of their environments. ‘Adaptation’, as it is used in modern biology, can name both the process by which organisms acquire this functional match, and the products of that process. Eyes, wings, beaks, camouflaging skin pigmentation and so forth, are all ‘adaptations’ in this second sense. Modern biological orthodoxy follows Darwin in giving a central role to natural selection in explaining the production of adaptations such as these. This much is uncontroversial. But a number of more contentious conceptual questions are raised when we look in more detail at the relationship between natural selection and adaptation. One of these questions concerns how we should define adaptation. It is tempting to characterize adaptations as functional traits – eyes are for seeing, large beaks are for cracking tough seed-casings. This in turn has led many commentators in biology and philosophy to define adaptations as those traits which have been shaped by natural selection for their respective tasks. Others – especially biologists – have complained that such a definition trivializes Darwin’s claim that natural selection explains adaptation. This claim was meant to be an important discovery, not a definitional consequence of the meaning of ‘adaptation’. These worries naturally lead on to the issues of how natural selection itself is to be understood, how it is meant to explain adaptation, and how it should be distinguished from other important evolutionary processes. These topics have a historical dimension: is Darwin’s understanding of natural selection, and its relationship to adaptation, the same as that of today’s evolutionary biology? Textbook presentations often say yes, and this is surely legitimate if we make the comparison in broad terms. But differences emerge when we look in more detail. Darwin, for example, seems to make the ‘struggle for existence’ an essential element of natural selection. It is not clear whether this is the case in modern presentations. And Darwin’s presentation is largely neutral on the inheritance mechanism that accounts for parent/offspring resemblance, while modern presentations sometimes insist that natural selection always implies a genetic underpinning to inheritance.

scholarly journals Selection for a threshold character in Drosophila II. Homeostatic behaviour on relaxation of selection

1966 ◽  
Vol 8 (2) ◽  
pp. 205-218 ◽  
Author(s):  
B. D. H. Latter
Keyword(s):  
Natural Selection ◽  
Artificial Selection ◽  
Competitive Ability ◽  
Reproductive Capacity ◽  
Correlated Responses ◽  
Genetic Sampling ◽  
Bristle Number ◽  
Large Populations ◽  
Selection For ◽  
Two Phases

This paper is concerned with three related aspects of the behaviour of populations under artificial selection for increased scutellar bristle number: (i) the pattern of response on the probit scale; (ii) the homeostatic behaviour of the selection lines on relaxation of artificial selection; and (iii) correlated responses in generation interval, reproductive capacity and competitive ability. The study was designed so that linkage would be a comparatively unimportant factor in promoting correlated responses to selection, and the effects of genetic sampling from generation to generation were also reduced to a low level.Progress from the base mean of 4·05 bristles in females to a level of almost 8 bristles has been shown to involve two distinct phases with realized heritabilities of 0·34 and 0·10 respectively, the zone of transition corresponding closely to the position of the 6/7 threshold on the underlying scale. In addition to an apparent average reduction of about 25% in the additive genetic standard deviation in phase II by comparison with phase I, the loss in response due to the opposition of natural selection has been shown to reach a maximum near the zone of separation of the two phases.The pattern of behaviour of the populations under artificial and natural selection has suggested the presence in the base population of genes of large effect on both bristle number and reproductive fitness. There is also evidence of additional genetic variation in bristle number which is effectively neutral with respect to fitness. Continued selection for increased scutellar bristle number in large populations has been shown to reduce mean competitive ability by more than 80%.

scholarly journals Ecological determinants of life-history evolution

1991 ◽  
Vol 332 (1262) ◽  
pp. 25-30 ◽  
Keyword(s):  
Drosophila Melanogaster ◽  
Life History ◽  
Natural Selection ◽  
Competitive Ability ◽  
Life History Evolution ◽  
Experimental System ◽  
Food Utilization ◽  
Physiological Basis ◽  
Laboratory Populations ◽  
Very High

Density-dependent natural selection has been studied, empirically with laboratory populations of Drosophila melanogaster . Populations kept at very high and low population density have become differentiated with respect to important fitness-related traits. There is now some understanding of the behavioural and physiological basis of these differences. These studies have identified larval competitive ability and efficiency of food utilization as traits that are negatively correlated with respect to effects on fitness. Theory that illuminates and motivates additional research with this experimental system has been lacking. Current research has focused on models that incorporate many details of Drosophila ecology in laboratory environments.

Inheritance and Natural Selection on Functional Traits

2003 ◽  
Vol 164 (S3) ◽  
pp. S21-S42 ◽  
Author(s):  
Monica A. Geber ◽  
Lauren R. Griffen
Keyword(s):  
Natural Selection ◽  
Functional Traits

scholarly journals Spatial eco-evolutionary feedbacks mediate coexistence in prey-predator systems

2019 ◽  
Author(s):  
Eduardo H. Colombo ◽  
Ricardo Martínez-García ◽  
Cristóbal López ◽  
Emilio Hernández-García
Keyword(s):  
Spatial Distribution ◽  
Natural Selection ◽  
Evolutionary Dynamics ◽  
Interspecific Interactions ◽  
Community Level ◽  
Evolutionary Processes ◽  
Species Extinction ◽  
Limited Mobility ◽  
Extinction Probabilities ◽  
The Stability

AbstractEco-evolutionary frameworks can explain certain features of communities in which ecological and evolutionary processes occur over comparable timescales. In the particular case of prey-predator systems, a combination of empirical and theoretical studies have explored this possibility, showing that the evolution of prey traits, predator traits or the coevolution of both can contribute to the stability of the community, as well as to the emergence of various types of population cycles. However, these studies overlook that interactions are spatially constrained, a crucial ingredient known to foster species coexistence per se. Here, we investigate whether evolutionary dynamics interacts with the spatial structure of a prey-predator community in which both species show limited mobility and predators perceptual ranges are subject to natural selection. In these conditions, our results unveil an eco-evolutionary feedback between species spatial mixing and predators perceptual range: different levels of species mixing select for different perceptual ranges, which in turn reshape the spatial distribution of preys and their interaction with predators. This emergent pattern of interspecific interactions feeds back to the efficiency of the various perceptual ranges, thus selecting for new ones. Finally, since prey-predator mixing is the key factor that regulates the intensity of predation, we explore the community-level implications of such feedback and show that it controls both coexistence times and species extinction probabilities.Author summaryEvolutionary processes occurring on temporal scales that are comparable to those of ecological change can result in reciprocal interactions between ecology and evolution termed eco-evolutionary feedbacks. Such interplay is clear in prey-predator systems, in which predation alters the distribution of resources (preys). In turn, changes in the abundance and spatial distribution of preys may lead to the evolution of new predation strategies, which may change again the properties of the prey population. Here, we investigate the interplay between limited mobility, species mixing, and finite perception in a prey-predator system. We focus on the case in which predator perceptual ranges are subject to natural selection and examine, via coexistence times and species extinction probabilities, whether the resulting eco-evolutionary dynamics mediates the stability of the community. Our results confirm the existence of such eco-evolutionary feedback and reveal its potential impact on community-level processes.

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