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Evolutionary Arms Race
In evolutionary biology, an evolutionary arms race is an ongoing struggle between competing sets of co-evolving genes, phenotypic and behavioral traits that develop escalating adaptations and counter-adaptations against each other, resembling the geopolitical concept of an arms race. These are often described as examples of positive feedback.Dawkins, R. 1996. ''The Blind Watchmaker'' New York: W. W. Norton. Note: This book was also published by Penguin in 1991. While the text is identical, page numbers differ The co-evolving gene sets may be in different species, as in an evolutionary arms race between a predator species and its prey (Vermeij, 1987), or a parasite and its host. Alternatively, the arms race may be between members of the same species, as in the manipulation/sales resistance model of communication (Dawkins & Krebs, 1979) or as in runaway evolution or Red Queen effects. One example of an evolutionary arms race is in sexual conflict between the sexes, often describe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Biology
Evolutionary biology is the subfield of biology that studies the evolutionary processes such as natural selection, common descent, and speciation that produced the diversity of life on Earth. In the 1930s, the discipline of evolutionary biology emerged through what Julian Huxley called the Modern synthesis (20th century), modern synthesis of understanding, from previously unrelated fields of biological research, such as genetics and ecology, systematics, and paleontology. The investigational range of current research has widened to encompass the genetic architecture of adaptation, molecular evolution, and the different forces that contribute to evolution, such as sexual selection, genetic drift, and biogeography. The newer field of evolutionary developmental biology ("evo-devo") investigates how embryogenesis is controlled, thus yielding a wider synthesis that integrates developmental biology with the fields of study covered by the earlier evolutionary synthesis. Subfields ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fisherian Runaway
Fisherian runaway or runaway selection is a sexual selection mechanism proposed by the mathematical biologist Ronald Fisher in the early 20th century, to account for the evolution of ostentatious male ornamentation by persistent, directional female choice. An example is the colourful and elaborate peacock plumage compared to the relatively subdued peahen plumage; the costly ornaments, notably the bird's extremely long tail, appear to be incompatible with natural selection. Fisherian runaway can be postulated to include sexually dimorphic phenotypic traits such as behavior expressed by a particular sex. Extreme and (seemingly) maladaptive sexual dimorphism represented a paradox for evolutionary biologists from Charles Darwin's time up to the modern synthesis. Darwin attempted to resolve the paradox by assuming heredity for both the preference and the ornament, and supposed an "aesthetic sense" in higher animals, leading to powerful selection of both characteristics in subseque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene-for-gene Relationship
The gene-for-gene relationship is a concept in plant pathology that plants and their diseases each have single genes that interact with each other during an infection. It was proposed by Harold Henry Flor who was working with rust (''Melampsora lini'') of flax ('' Linum usitatissimum''). Flor showed that the inheritance of both resistance in the host and parasite ability to cause disease is controlled by pairs of matching genes. One is a plant gene called the resistance (''R'') gene. The other is a parasite gene called the avirulence (''Avr'') gene. Plants producing a specific R gene product are resistant towards a pathogen that produces the corresponding ''Avr'' gene product. Gene-for-gene relationships are a widespread and very important aspect of plant disease resistance. Another example can be seen with '' Lactuca serriola'' versus '' Bremia lactucae''. Clayton Oscar Person was the first scientist to study plant pathosystem ratios rather than genetics ratios in host-paras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R Gene
Resistance genes (R-Genes) are genes in plant genomes that convey plant disease resistance against pathogens by producing R proteins. The main class of R-genes consist of a nucleotide binding domain (NB) and a leucine rich repeat (LRR) domain(s) and are often referred to as (NB-LRR) R-genes or NLRs. Generally, the NB domain binds either ATP/ADP or GTP/GDP. The LRR domain is often involved in protein-protein interactions as well as ligand binding. NB-LRR R-genes can be further subdivided into toll interleukin 1 receptor (TIR-NB-LRR) and coiled-coil (CC-NB-LRR). Resistance can be conveyed through a number of mechanisms including: * The R protein interacts directly with an Avr geneAvirulence gene) product of a pathogen (see Gene-for-Gene relationship). * The R protein guards another protein that detects degradation by an Avr gene (see Guard Hypothesis). * The R protein may detect a Pathogen-Associated Molecular Pattern or PAMP (alternatively called MAMP for microbe-a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoospore
A zoospore is a motile asexual spore that uses a flagellum for locomotion in aqueous or moist environments. Also called a swarm spore, these spores are created by some protists, bacteria, and fungi to propagate themselves. Certain zoospores are infectious and transmittable, such as '' Batrachochytrium dendrobatidis'', a fungal zoospore that causes high rates of mortality in amphibians. Diversity General morphology Zoospores are composed of a microtubular cytoskeleton base which extends from the base of the flagellum. The complexity and structure of this cytoskeleton is variable and is largely dependent on volume and size. One common feature of zoospores is their asymmetrical shape; a result of the ventral grove housing the flagella base. Certain zoospores progress through different phases, the first phase commonly referred to as 'the initial'. Others form cysts that vary tremendously in volume (14-4905 cubic micrometers) and shape, each with distinctive hair structures. Flag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bintje
Bintje is a middle-early ripening potato variety bred in the Netherlands by the Frisian schoolmaster K.L. de Vries in 1904 from (Munstersen x Fransen) and marketed for the first time in 1910. The name of the potato, a diminutive of Benedict, was borrowed from one of his former students. Bintje plants are medium-sized and erect, with purplish stems, dark green leaves and white flowers. Bintje produces large oval-shaped tubers with pale yellow skin and yellow flesh. It has shallow eyes. The sprouts are purplish. This high-yielding variety is widely grown in Europe and North Africa. It is used for boiling, baking, and for fries, mashed potato and potato chips. It is the most widely cultivated potato in France and Belgium. Bintje is immune to potato virus A. It has moderate resistance to potato leafroll virus. It is susceptible to netted scab, common scab Common scab is a plant disease of root and tuber crops caused by a small number of ''Streptomyces'' species, specifically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plants Certifiés Bintje
Plants are the eukaryotes that form the kingdom Plantae; they are predominantly photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars from carbon dioxide and water, using the green pigment chlorophyll. Exceptions are parasitic plants that have lost the genes for chlorophyll and photosynthesis, and obtain their energy from other plants or fungi. Most plants are multicellular, except for some green algae. Historically, as in Aristotle's biology, the plant kingdom encompassed all living things that were not animals, and included algae and fungi. Definitions have narrowed since then; current definitions exclude fungi and some of the algae. By the definition used in this article, plants form the clade Viridiplantae (green plants), which consists of the green algae and the embryophytes or land plants (hornworts, liverworts, mosses, lycophytes, ferns, conifers and other gymnosperm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leigh Van Valen
Leigh Van Valen (August 12, 1935 – October 16, 2010) was an American evolutionary biologist. At the time of his death, he was professor emeritus in the Department of Ecology and Evolution at the University of Chicago. Research and interests Amongst other work, Van Valen's proposed "Law of Extinction", known as Van Valen's law, drew upon the apparent constant probability (as opposed to rate) of extinction in families of related organisms, based on data compiled from existing literature on the duration of tens of thousands of genera throughout the fossil record. Van Valen proposed the Red Queen hypothesis (1973), as an explanatory tangent to the Law of Extinction. The Red Queen Hypothesis captures the idea that there is a constant 'arms race' between co-evolving species. Its name is a reference to the Red Queen's race in Lewis Carroll's '' Through the Looking-Glass'', in which the chess board moves such that Alice must continue running just to stay in the same place. Van V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Queen's Hypothesis
The Red Queen's hypothesis is a hypothesis in evolutionary biology proposed in 1973, that species must constantly adapt, evolve, and proliferate in order to survive while pitted against ever-evolving opposing species. The hypothesis was intended to explain the constant (age-independent) extinction probability as observed in the paleontological record caused by co-evolution between competing species; however, it has also been suggested that the Red Queen hypothesis explains the advantage of sexual reproduction (as opposed to asexual reproduction) at the level of individuals,Bell, G. (1982). The Masterpiece Of Nature: The Evolution and Genetics of Sexuality. University of California Press, Berkeley, 378 pp. and the positive correlation between speciation and extinction rates in most higher taxa. Origin In 1973, Leigh Van Valen proposed the hypothesis as an "explanatory tangent" to explain the "law of extinction" known as "Van Valen's law", which states that the probability of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antagonistic Coevolution
Sexual antagonistic co-evolution is the relationship between males and females where sexual morphology changes over time to counteract the opposite's sex traits to achieve the maximum reproductive success. This has been compared to an arms race between sexes. In many cases, male mating behavior is detrimental to the female's fitness. For example, when insects reproduce by means of traumatic insemination, it is very disadvantageous to the female's health. During mating, males will try to inseminate as many females as possible, however, the more times a female's abdomen is punctured, the less likely she is to survive. Females that possess traits to avoid multiple matings will be more likely to survive, resulting in a change in morphology. In males, genitalia is relatively simple and more likely to vary among generations compared to female genitalia. This results in a new trait that females have to avoid in order to survive. Additionally, sexual antagonistic co-evolution can be the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
