HOME
*





Harrison's Rule
Harrison's rule is an observation in evolutionary biology by Launcelot Harrison which states that in comparisons across closely related species, host and parasite body sizes tend to covary positively. Parasite species' body size increases with host species' body size Launcelot Harrison, an Australian authority in zoology and parasitology, published a study in 1915 concluding that host and parasite body sizes tend to covary positively, a covariation later dubbed as 'Harrison's rule'. Harrison himself originally proposed it to interpret the variability of congeneric louse species. However, subsequent authors verified it for a wide variety of parasitic organisms including nematodes, Rhizocephala , rhizocephalan barnacles, fleas, lice, ticks, parasitic flies and mites, as well as herbivorous insects associated with specific host plants. The variability of parasite species' body size increases with host species' body size Robert Poulin (zoologist), Robert Poulin observed that in co ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Launcelot Harrison 1880-1928
Lancelot du Lac (French for Lancelot of the Lake), also written as Launcelot and other variants (such as early German ''Lanzelet'', early French ''Lanselos'', early Welsh ''Lanslod Lak'', Italian ''Lancillotto'', Spanish ''Lanzarote del Lago'', and Welsh ''Lawnslot y Llyn''), is a character in some versions of Matter of Britain, Arthurian legend, where he is typically depicted as King Arthur's close companion and one of the greatest Knights of the Round Table. In the French-inspired Arthurian chivalric romance tradition, Lancelot is an orphaned son of King Ban of the lost Kingdom of Benoic, raised in the fairy realm by the Lady of the Lake. A hero of many battles, quests and tournaments, and famed as a nearly unrivalled Swordsmanship, swordsman and Jousting, jouster, Lancelot becomes the lord of the castle Joyous Gard and personal champion of Arthur's wife, Guinevere, Queen Guinevere, despite suffering from frequent and sometimes prolonged fits of madness. But when his adultery ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Lice
Louse ( : lice) is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been recognized as an order, infraorder, or a parvorder, as a result of developments in phylogenetic research. Lice are obligate parasites, living externally on warm-blooded hosts which include every species of bird and mammal, except for monotremes, pangolins, and bats. Lice are vectors of diseases such as typhus. Chewing lice live among the hairs or feathers of their host and feed on skin and debris, while sucking lice pierce the host's skin and feed on blood and other secretions. They usually spend their whole life on a single host, cementing their eggs, called nits, to hairs or feathers. The eggs hatch into nymphs, which moult three times before becoming fully grown, a process that takes about four weeks. Genetic evidence indicates that lice are a highly modified lineage of Psocoptera (now called Ps ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Host–parasite Coevolution
Host–parasite coevolution is a special case of coevolution, where a host and a parasite continually adapt to each other. This can create an evolutionary arms race between them. A more benign possibility is of an evolutionary trade-off between transmission and virulence in the parasite, as if it kills its host too quickly, the parasite will not be able to reproduce either. Another theory, the Red Queen hypothesis, proposes that since both host and parasite have to keep on evolving to keep up with each other, and since sexual reproduction continually creates new combinations of genes, parasitism favours sexual reproduction in the host. The genetic changes involved are changes in frequencies of alleles, variant forms of individual genes, within populations. These are determined by three main types of selection dynamics: negative frequency-dependent selection when a rare allele has a selective advantage; heterozygote advantage; and directional selection near an advantageous allele ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Allometry
Allometry is the study of the relationship of body size to shape, anatomy, physiology and finally behaviour, first outlined by Otto Snell in 1892, by D'Arcy Thompson in 1917 in ''On Growth and Form'' and by Julian Huxley in 1932. Overview Allometry is a well-known study, particularly in statistical shape analysis for its theoretical developments, as well as in biology for practical applications to the differential growth rates of the parts of a living organism's body. One application is in the study of various insect species (e.g., Hercules beetles), where a small change in overall body size can lead to an enormous and disproportionate increase in the dimensions of appendages such as legs, antennae, or horns The relationship between the two measured quantities is often expressed as a power law equation (Allometric equation) which expresses a remarkable scale symmetry: : y = kx^a \,\! or in a logarithmic form: : \log y = a \log x + \log k\,\! or similarly \ln y = a \ln x ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Philopteridae
The Philopteridae are a family of Ischnocera, chewing lice mostly parasitic on birds. The taxonomy and systematics of the group are in need of revision; the Philopteridae are almost certainly paraphyletic. Genera Some notable species are also listed. * '' Acidoproctus'' * '' Acutifrons'' * '' Aegypoecus'' * '' Alcedoecus'' * '' Alcedoffula'' * '' Anaticola'' * '' Anatoecus'' * '' Aquanirmus'' * '' Ardeicola'' * '' Ardeiphagus'' * '' Auricotes'' * '' Austrogoniodes'' * '' Austrophilopterus'' * '' Bedfordiella'' * '' Bizarrifrons'' * '' Bobdalglieshia'' * '' Bothriometopus'' * ''Brueelia'' * '' Bucerocophorus'' * '' Buceroemersonia'' * '' Buceronirmus'' * '' Bucorvellus'' * '' Buerelius'' * ''Campanulotes'' * '' Capraiella'' * '' Caracaricola'' * '' Carduiceps'' * '' Centropodiella'' * '' Chelopistes'' * '' Cirrophthirius'' * '' Colilipeurus'' * '' Colinicola'' * '' Coloceras'' * ''Columbicola'' ** ''Columbicola extinctus ''Columbicola extinctus'', also known as the passenger p ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Menoponidae
Menoponidae is a monophyletic family of lice in the superfamily of chewing lice, Amblycera, often referred to as the chicken body louse family. They are ectoparasites of a wide range of birds including chickens, which makes them important to understand for veterinary science and for human health. However, Menoponidae are not exclusive to poultry and are common parasites for migratory birds, with more and more species being discovered every year. Biology Genera and species within the family Menoponidae are identified by their short antennae, concealed in grooves behind the eyes. To the untrained eye, it may appear as though they have no antennae. Most lice also further specialize to specific regions on their hosts such as the fluff at the base of the tail, the head, and the shaft. In fact, if a species that is better suited to tail feathers is presented with the opportunity to infest a different type of feather, they will make an attempt to eat those feathers but will fail to rep ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Ricinidae
The Ricinidae are a family of a larger group Amblycera of the chewing lice. Most commonly they are ectoparasites of birds. The family includes the genus ''Ricinus ''Ricinus communis'', the castor bean or castor oil plant, is a species of perennial flowering plant in the spurge family, Euphorbiaceae. It is the sole species in the monotypic genus, ''Ricinus'', and subtribe, Ricininae. The evolution of cas ...''. Bernard C. Nelson (1972): ''A Revision of the New World Species of ''Ricinus'' (Mallophaga). Occurring on Passeriformes (Aves)'', University of California Publications in Entomology Volume 68, University of California Press, Berkeley & Los Angeles,PDF References Lice Insect families {{louse-stub ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Power Law
In statistics, a power law is a Function (mathematics), functional relationship between two quantities, where a Relative change and difference, relative change in one quantity results in a proportional relative change in the other quantity, independent of the initial size of those quantities: one quantity varies as a Exponentiation, power of another. For instance, considering the area of a square in terms of the length of its side, if the length is doubled, the area is multiplied by a factor of four. Empirical examples The distributions of a wide variety of physical, biological, and man-made phenomena approximately follow a power law over a wide range of magnitudes: these include the sizes of craters on the moon and of solar flares, the foraging pattern of various species, the sizes of activity patterns of neuronal populations, the frequencies of words in most languages, frequencies of family names, the species richness in clades of organisms, the sizes of power outages, volcanic ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Statistical Dispersion
In statistics, dispersion (also called variability, scatter, or spread) is the extent to which a Probability distribution, distribution is stretched or squeezed. Common examples of measures of statistical dispersion are the variance, standard deviation, and interquartile range. For instance, when the variance of data in a set is large, the data is widely scattered. On the other hand, when the variance is small, the data in the set is clustered. Dispersion is contrasted with location or central tendency, and together they are the most used properties of distributions. Measures A measure of statistical dispersion is a nonnegative real number that is zero if all the data are the same and increases as the data become more diverse. Most measures of dispersion have the same units of measurement, units as the quantity being measured. In other words, if the measurements are in metres or seconds, so is the measure of dispersion. Examples of dispersion measures include: * Standard deviat ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  




Robert Poulin (zoologist)
Robert Poulin is an evolutionary ecologist specialising in the ecology of parasitism. He is a professor of zoology at the University of Otago and a Fellow of the Royal Society of New Zealand. Biography Poulin grew up in Canada, taking his bachelor's degree in aquatic biology at McGill University, Montreal and gaining his doctorate at Université Laval, Quebec City. He became a researcher in Quebec. He moved to New Zealand in 1992, where he is a professor of zoology, leading a research group studying parasite ecology at the University of Otago. He has written numerous papers and book chapters: his ''Evolutionary Ecology of Parasites'' has been cited at least 2272 times; his co-written ''Parasites in food webs: the ultimate missing links'' has been cited over 800 times; his ''Parasite Biodiversity'' and five other works have each been cited over 500 times; 12 other works have been cited over 250 times each. In all he has been cited at least 39,900 times, with an h-index of 101 and ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Evolution (journal)
''Evolution: International Journal of Organic Evolution'', is a monthly scientific journal that publishes significant new results of empirical or theoretical investigations concerning facts, processes, mechanics, or concepts of evolutionary phenomena and events. ''Evolution'' is published by the Society for the Study of Evolution. Its current editor-in-chief is Tracey Chapman. Former editors-in-chief The journal was founded soon after the Second World War. Its first editor was the evolutionary geneticist Ernst Mayr. * Ruth Geyer Shaw, July 2013 – 2017 * Daphne Fairbairn Daphne (; ; el, Δάφνη, , ), a minor figure in Greek mythology, is a naiad, a variety of female nymph associated with fountains, wells, springs, streams, brooks and other bodies of freshwater. There are several versions of the myth in whi ..., 2010- June 2013 References External linksOfficial website Evolutionary biology journals Publications established in 1947 Academic journals published by l ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Zoological Journal Of The Linnean Society
The ''Zoological Journal of the Linnean Society'' is a monthly peer-reviewed scientific journal covering zoology published by Oxford University Press on behalf of the Linnean Society. The editor-in-chief is Maarten Christenhusz (Linnean Society). It was established in 1856 as the ''Journal of the Proceedings of the Linnean Society of London. Zoology'' and renamed ''Journal of the Linnean Society of London, Zoology'' in 1866. It obtained its current title in 1969. Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 3.286. References External links * Zoology journals Linnean Society of London Monthly journals Academic journa ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]