Search results for "Red Queen hypothesis"
showing 6 items of 6 documents
Frequency-Dependent Selection in a Mammalian RNA Virus
1997
RNA viruses have been used as experimental systems to test evolutionary hypotheses such as Muller's ratchet (Chao 1990; Duarte et al. 1992, 1993; Clarke et al. 1993), the Red Queen hypothesis (Clarke et al. 1994), the nature of the adaptive topography (Elena, 1995; Elena et al. 1996), and the dynamics of adaptive evolution (Elena 1995; Novella et al. 1995). Two hypotheses which have received attention in virus studies are the competitive exclusion principle and frequency-dependent selection. The competitive exclusion principle (Hardin 1960) states that two populations or species competing for the same limiting resource cannot stably coexist because one competitor will displace the other. An…
Evidence of the Red-Queen Hypothesis from Accelerated Rates of Evolution of Genes Involved in Biotic Interactions in Pneumocystis.
2018
Pneumocystis species are ascomycete fungi adapted to live inside the lungs of mammals. These ascomycetes show extensive stenoxenism, meaning that each species of Pneumocystis infects a single species of host. Here, we study the effect exerted by natural selection on gene evolution in the genomes of three Pneumocystis species. We show that genes involved in host interaction evolve under positive selection. In the first place, we found strong evidence of episodic diversifying selection in Major surface glycoproteins (Msg). These proteins are located on the surface of Pneumocystis and are used for host attachment and probably for immune system evasion. Consistent with their function as antigen…
The red tooth hypothesis: A computational model of predator-prey relations, protean escape behavior and sexual reproduction
2009
This paper presents an extension of the Red Queen Hypothesis (hereafter, RQH) that we call the Red Tooth Hypothesis (RTH). This hypothesis suggests that predator-prey relations may play a role in the maintenance of sexual reproduction in many higher animals. RTH is based on an interaction between learning on the part of predators and evolution on the part of prey. We present a simple predator-prey computer simulation that illustrates the effects of this interaction. This simulation suggests that the optimal escape strategy from the prey's standpoint would be to have a small number of highly reflexive, largely innate (and, therefore, very fast) escape patterns, but that would also be unlearn…
Sexual selection and intelligence: Does sexual reproduction drive the evolution of intelligence?
2009
Abstract The basal hypothesis discussed here is the idea that brain architecture could be plastic on a very basal, genetic level due to sexual recombination and reassortment of alleles of genes related to brain development, e.g., neuronal cell adhesion molecules (NCAMs) and others. The role of sexual reassortment leads the study of brain development, species behavior and intelligence to a new version of the so-called “Red Queen Hypothesis”: using the mechanism described here, a kind of runaway selection mechanism seems to arise. Even if NCAMs are almost constant within an individual, they seem to act very differently at the population level and so the role of reassorting polymorphic NCAM- (…
PARASITES AND SEXUAL REPRODUCTION IN PSYCHID MOTHS
2004
Persistence of sexual reproduction among coexisting asexual competitors has been a major paradox in evolutionary biology. The number of empirical studies is still very limited, as few systems with coexisting sexual and strictly asexual lineages have been found. We studied the ecological mechanisms behind the simultaneous coexistence of a sexually and an asexually reproducing closely related species of psychid moth in Central Finland between 1999 and 2001. The two species compete for the same resources and are often infected by the same hymenopteran parasitoids. They are extremely morphologically and behaviorally similar and can be separated only by their reproductive strategy (sexual vs. as…
Low parasitism rates in parthenogenetic bagworm moths do not support the parasitoid hypothesis for sex
2012
The parasite hypothesis for sex is one of the many theories that have been suggested to solve the mystery of the widespread occurrence of sex despite its high short-term costs. It suggests that sexual lineages have an evolutionary advantage over parthenogens because they can frequently generate new genotypes that are temporarily less prone to coevolving parasites. In this study, we looked for further supporting evidence for the parasite hypothesis of sex in an attempt to understand the coexistence of sexual and parthenogenetic bagworm moths (Naryciinae). The bagworm moths and their parasitoids form one of the few natural host-parasite systems where sexual and parthenogenetic hosts are appar…