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Phylogenetic Diversity
Phylogenetic diversity is a measure of biodiversity which incorporates Phylogenetics, phylogenetic difference between species. It is defined and calculated as "the sum of the lengths of all those branches that are members of the corresponding minimum spanning path", in which 'branch' is a segment of a cladogram, and the minimum spanning path is the minimum distance between the two nodes. This definition is distinct from earlier measures which attempted to incorporate phylogenetic diversity into conservation planning, such as the measure of 'taxic diversity' introduced by Vane-Wright, Humphries, and William. The concept of phylogenetic diversity has been rapidly adopted in conservation planning, with programs such as the Zoological Society of London's EDGE of Existence programme focused on evolutionary distinct species. Similarly, the World Wide Fund for Nature, WWF's Global 200 also includes unusual evolutionary phenomena in their criteria for selecting target ecoregions. Some studi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenodon Punctatus In Waikanae, New Zealand
The tuatara (''Sphenodon punctatus'') is a species of reptile Endemism, endemic to New Zealand. Despite its close resemblance to lizards, it is actually the only extant member of a distinct lineage, the previously highly diverse order Rhynchocephalia. The name is derived from the Māori language and means "peaks on the back". The single extant species of tuatara is the only surviving member of its order, which was highly diverse during the Mesozoic era. Rhynchocephalians first appeared in the fossil record during the Triassic, around 240 million years ago, and reached worldwide distribution and peak diversity during the Jurassic, when they represented the world's dominant group of small reptiles. Rhynchocephalians declined during the Cretaceous, with their youngest records outside New Zealand dating to the Paleocene. Their closest living relatives are Squamata, squamates (lizards and snakes). Tuatara are of interest for studying the evolution of reptiles. Tuatara are gree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Measure Of Biodiversity
A variety of objective means exist to empirically measure biodiversity. Each measure relates to a particular use of the data, and is likely to be associated with the variety of genes. Biodiversity is commonly measured in terms of taxonomic richness of a geographic area over a time interval. In order to calculate biodiversity, species evenness, species richness, and species diversity are to be obtained first. ''Species evenness'' is the relative number of individuals of each species in a given area. ''Species richness'' is the number of species present in a given area. ''Species diversity'' is the relationship between species evenness and species richness. There are many ways to measure biodiversity within a given ecosystem. However, the two most popular are Shannon-Weaver diversity index, commonly referred to as Shannon diversity index, and the other is Simpsons diversity index. Although many scientists prefer to use Shannon's diversity index simply because it takes into account sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetics
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data and observed heritable traits of DNA sequences, protein amino acid sequences, and morphology. The results are a phylogenetic tree—a diagram depicting the hypothetical relationships among the organisms, reflecting their inferred evolutionary history. The tips of a phylogenetic tree represent the observed entities, which can be living taxa or fossils. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the taxa represented on the tree. An unrooted tree diagram (a network) makes no assumption about directionality of character state transformation, and does not show the origin or "root" of the taxa in question. In addition to their use for inferring phylogenetic pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum Spanning Path
In mathematical analysis, the maximum and minimum of a function are, respectively, the greatest and least value taken by the function. Known generically as extremum, they may be defined either within a given range (the ''local'' or ''relative'' extrema) or on the entire domain (the ''global'' or ''absolute'' extrema) of a function. Pierre de Fermat was one of the first mathematicians to propose a general technique, adequality, for finding the maxima and minima of functions. As defined in set theory, the maximum and minimum of a set are the greatest and least elements in the set, respectively. Unbounded infinite sets, such as the set of real numbers, have no minimum or maximum. In statistics, the corresponding concept is the sample maximum and minimum. Definition A real-valued function ''f'' defined on a domain ''X'' has a global (or absolute) maximum point at ''x''∗, if for all ''x'' in ''X''. Similarly, the function has a global (or absolute) minimum point at ''x''∗, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladogram
A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conservation Planning
Conservation is the preservation or efficient use of resources, or the conservation of various quantities under physical laws. Conservation may also refer to: Environment and natural resources * Nature conservation, the protection and management of the environment and natural resources **Wetland conservation, protecting and preserving areas where water exists at or near the Earth's surface, such as swamps, marshes and bogs. * Conservation biology, the science of protection and management of biodiversity * Conservation movement, political, environmental, or social movement that seeks to protect natural resources, including biodiversity and habitat * Conservation organization, an organization dedicated to protection and management of the environment or natural resources * Wildlife conservation, the practice of protecting wild species and their habitats in order to prevent species from going extinct * ''Conservation'' (magazine), published by the Society for Conservation Biolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoological Society Of London
The Zoological Society of London (ZSL) is a charity and organization devoted to the worldwide animal conservation, conservation of animals and their habitat conservation, habitats. It was founded in 1826. Since 1828, it has maintained London Zoo, and since 1931 Whipsnade Zoo. History On 29 November 1822, the birthday of John Ray, "the father of modern zoology", a meeting held in the Linnean Society in Soho Square led by Rev. William Kirby (entomologist), William Kirby, resolved to form a "Zoological Club of the Linnean Society of London". Between 1816 and 1826, discussions between Stamford Raffles, Humphry Davy, Joseph Banks and others led to the idea that London should have an establishment similar to the Jardin des Plantes in Paris. It would house a zoological collection "which should interest and amuse the public." The society was founded in April 1826 by Stamford Raffles, Sir Stamford Raffles, the Henry Petty-Fitzmaurice, 3rd Marquess of Lansdowne, Marquess of Lansdo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Wide Fund For Nature
The World Wide Fund for Nature (WWF) is a Swiss-based international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the World Wildlife Fund, which remains its official name in Canada and the United States. WWF is the world's largest conservation organization, with over 5 million supporters worldwide, working in more than 100 countries and supporting around 3,000 conservation and environmental projects. It has invested over $1 billion in more than 12,000 conservation initiatives since 1995. WWF is a foundation with 65% of funding from individuals and bequests, 17% from government sources (such as the World Bank, FCDO, and USAID) and 8% from corporations in 2020. WWF aims to "stop the degradation of the planet's natural environment and to build a future in which humans live in harmony with nature." '' Living Planet Report'' has been published every two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global 200
The Global 200 is the list of ecoregions identified by the World Wide Fund for Nature ( WWF), the global conservation organization, as priorities for conservation. According to WWF, an ecoregion is defined as a "relatively large unit of land or water containing a characteristic set of natural communities that share a large majority of their species dynamics, and environmental conditions". For example, based on their levels of endemism, Madagascar gets multiple listings, ancient Lake Baikal gets one, and the North American Great Lakes get none. The WWF assigns a conservation status to each ecoregion in the Global 200: critical or endangered; vulnerable; and relatively stable or intact. Over half of the ecoregions in the Global 200 are rated endangered. Background The WWF has identified 867 terrestrial ecoregions across the Earth's land surface, as well as freshwater and marine ecoregions. The goal of this classification system is to ensure that the full range of ecosystems wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecoregion
An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species. The biodiversity of flora, fauna and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. In theory, biodiversity or conservation ecoregions are relatively large areas of land or water where the probability of encountering different species and communities at any given point remains relatively constant, within an acceptable range of variation (largely undefined at this point). Ecoregions are also known as "ecozones" ("ecological zones"), although that term may also refer to biogeographic realms. Three caveats are appropriate for all bio-geographic mapping approaches. Firstly, no single bio-geographic fram ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Diversity
In ecology, alpha diversity (α-diversity) is the mean species diversity in a site at a local scale. The term was introduced by R. H. WhittakerWhittaker, R. H. (1960) Vegetation of the Siskiyou Mountains, Oregon and California. Ecological Monographs, 30, 279–338. Whittaker, R. H. (1972). Evolution and Measurement of Species Diversity. Taxon, 21, 213-251. together with the terms beta diversity (β-diversity) and gamma diversity (γ-diversity). Whittaker's idea was that the total species diversity in a landscape (gamma diversity) is determined by two different things, the mean species diversity in sites at a more local scale (alpha diversity) and the differentiation among those sites (beta diversity). Scale considerations Both the area or landscape of interest and the sites within it may be of very different sizes in different situations, and no consensus has been reached on what spatial scales are appropriate to quantify alpha diversity. It has therefore been proposed that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
