Search results for "Evolutionary Theory"

Gödel and the Blind Watchmaker

2015

While accepting that contingency is key to biological evolution, we wonder how much need there is for it. It is extremely difficult to talk about trends in evolution, but the fact remains that they are found here and there when evolutionary experiments are repeated. But we should ask, for example, whether there is an unavoidable tendency of life towards progressive complexity . This chapter deals with certain theoretical considerations from Logic and Computing on the conditions necessary to formulate a predictive evolutionary theory .

The art of animal colouring

2010

Can sexual selection theory inform genetic management of captive populations? A review

2014

International audience; Captive breeding for conservation purposes presents a serious practical challenge because several conflicting genetic processes (i.e., inbreeding depression, random genetic drift and genetic adaptation to captivity) need to be managed in concert to maximize captive population persistence and reintroduction success probability. Because current genetic management is often only partly successful in achieving these goals, it has been suggested that management insights may be found in sexual selection theory (in particular, female mate choice). We review the theoretical and empirical literature and consider how female mate choice might influence captive breeding in the co…

The discrimination of alternative male morphologies

2001

Male dimorphisms represent alternative selective regimes within a sex. As such, they can be used as a powerful tool in testing evolutionary theory. However, to realize this potential, we need to be able to accurately discriminate individuals into two separate morphs. In this article we discuss the existing methods and propose a new one. We test our method with data from three dimorphic species and compare these results to results with existing methods. We conclude that existing methods often misclassify a large proportion of individuals, but applying our method notably reduces these errors.

Phage-driven loss of virulence in a fish pathogenic bacterium

2012

Parasites provide a selective pressure during the evolution of their hosts, and mediate a range of effects on ecological communities. Due to their short generation time, host-parasite interactions may also drive the virulence of opportunistic bacteria. This is especially relevant in systems where high densities of hosts and parasites on different trophic levels (e.g. vertebrate hosts, their bacterial pathogens, and virus parasitizing bacteria) co-exist. In farmed salmonid fingerlings, Flavobacterium columnare is an emerging pathogen, and phage that infect F. columnare have been isolated. However, the impact of these phage on their host bacterium is not well understood. To study this, four s…

Historical and Contemporary Background

2016

The second chapter provides a brief historical background of fundamental motivation by focussing on two main themes given in chronological order. The first adopts a historical approach, identifying several theoretical traditions and influential theorists who have worked on the idea of fundamental motivation. This brief overview includes ideas preceding the rise of evolutionary theory and the subsequent emergence of such contemporary theoretical traditions as psychoanalysis, behaviourism and humanistic psychology. The second theme centres on the identification of the most recent contemporary contributions that are quite similar to the main ideas of this book. The concluding section comments …

Scientific Reports

2020

.-- Halimubieke, Naerhulan et al.

Flexible parental care: Uniparental incubation in biparentally incubating shorebirds

2017

The relative investment of females and males into parental care might depend on the population’s adult sex-ratio. For example, all else being equal, males should be the more caring sex if the sex-ratio is male biased. Whether such outcomes are evolutionary fixed (i.e. related to the species’ typical sex-ratio) or whether they arise through flexible responses of individuals to the current population sex-ratio remains unclear. Nevertheless, a flexible response might be limited by the evolutionary history of the species, because one sex may have lost the ability to care or because a single parent cannot successfully raise the brood. Here, we demonstrate that after the disappearance of one pare…

A Lack of Sexual Dimorphism in Width-to-Height Ratio in White European Faces Using 2D Photographs, 3D Scans, and Anthropometry

2012

Facial width-to-height ratio has received a great deal of attention in recent research. Evidence from human skulls suggests\ud that males have a larger relative facial width than females, and that this sexual dimorphism is an honest signal of\ud masculinity, aggression, and related traits. However, evidence that this measure is sexually dimorphic in faces, rather than\ud skulls, is surprisingly weak. We therefore investigated facial width-to-height ratio in three White European samples using\ud three different methods of measurement: 2D photographs, 3D scans, and anthropometry. By measuring the same\ud individuals with multiple methods, we demonstrated high agreement across all measures. Ho…

Dynamics in stochastic evolutionary models

2016

We characterize transitions between stochastically stable states and relative ergodic probabilities in the theory of the evolution of conventions. We give an application to the fall of hegemonies in the evolutionary theory of institutions and conflict, and illustrate the theory with the fall of the Qing dynasty and the rise of communism in China.