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Pseudocyphellaria Glabra
''Pseudocyphellaria glabra'' is a species of corticolous (bark-dwelling), foliose lichen in the family Peltigeraceae. It has a pale-green upper thallus surface, a white medulla and white pseudocyphellae (tiny pores for gas exchange). Distribution ''Pseudocyphellaria glabra'' has a disjunct distribution that is separated by the Tasman Sea and the Pacific Ocean. The lichen is found in southeastern Australia (including Tasmania), New Zealand, Argentina, Chile, Lord Howe Island, Macquarie Island, and the subantarctic islands of New Zealand. Population genomic analyses suggest that lichens from these different locations are genetically distinct, but regular long-distance dispersal of spores during the Quaternary probably prevented the local populations from evolving into distinct species. Taxonomy The lichen was first formally described in 1844 by Joseph Dalton Hooker and Thomas Taylor as a member of the genus ''Sticta''. Their original report recorded occurrences from the Auck ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hook
A hook is a tool consisting of a length of material, typically metal, that contains a portion that is curved or indented, such that it can be used to grab onto, connect, or otherwise attach itself onto another object. In a number of uses, one end of the hook is pointed, so that this end can pierce another material, which is then held by the curved or indented portion. Some kinds of hooks, particularly fish hooks, also have a barb, a backwards-pointed projection near the pointed end of the hook to ensure that once the hook is embedded in its target, it can not easily be removed. Variations * Bagging hook, a large sickle or reaping hook used for harvesting grain * Bondage hook, used in sexual bondage play * Cabin hook, a hooked bar that engages into an eye screw, used on doors * Cap hook, hat ornament of the 15th and 16th centuries * Cargo hook (helicopter), different types of hook systems for helicopters * Crochet hook, used for crocheting thread or yarn * Drapery hook, for ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medulla (lichenology)
The medulla is a horizontal layer within a lichen thallus. It is a loosely arranged layer of interlaced hyphae below the upper cortex and photobiont A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Galloway, D.J. (1992). Flora of Australia - ''Lichen Glossary'' The medulla generally has a cottony appearance. It is the widest layer of a heteromerous lichen thallus. References Fungal morphology and anatomy Lichenology {{lichen-stub ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Description
A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have been described previously or are related. In order for species to be validly described, they need to follow guidelines established over time. Zoological naming requires adherence to the ICZN code, plants, the ICN, viruses ICTV, and so on. The species description often contains photographs or other illustrations of type material along with a note on where they are deposited. The publication in which the species is described gives the new species a formal scientific name. Some 1.9 million species have been identified and described, out of some 8.7 million that may actually exist. Millions more have become extinct throughout the existence of life on Earth. Naming process A name of a new species becomes valid (available in zo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speciation
Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages. Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book ''On the Origin of Species''. He also identified sexual selection as a likely mechanism, but found it problematic. There are four geographic modes of speciation in nature, based on the extent to which speciating populations are isolated from one another: allopatric speciation, allopatric, peripatric speciation, peripatric, parapatric speciation, parapatric, and sympatric speciation, sympatric. Speciation may also be induced artificially, through animal husbandry, agriculture, or laboratory experiments of speciation, laboratory experiments. Whether genetic drift is a minor or major contributor to speciation is the subject of much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today, although a third epoch, the Anthropocene, has been proposed but is not yet officially recognised by the ICS). The Quaternary Period is typically defined by the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. Research history In 1759 Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four successive formations or "orders" ( it, quattro ordini). The term "quaternary" was introduced by Jules Desnoye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Dispersal
Biological dispersal refers to both the movement of individuals (animals, plants, fungi, bacteria, etc.) from their birth site to their breeding site ('natal dispersal'), as well as the movement from one breeding site to another ('breeding dispersal'). Dispersal is also used to describe the movement of propagules such as seeds and spores. Technically, dispersal is defined as any movement that has the potential to lead to gene flow. The act of dispersal involves three phases: departure, transfer, settlement and there are different fitness costs and benefits associated with each of these phases. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population genetics, and species distribution. Understanding dispersal and the consequences both for evolutionary strategies at a species level, and for processes at an ecosystem level, requires understanding on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Genomics
Population genomics is the large-scale comparison of DNA sequences of populations. Population genomics is a neologism that is associated with population genetics. Population genomics studies genome-wide effects to improve our understanding of microevolution so that we may learn the phylogenetic history and demography of a population.Luikart, G.; England, P. R.; Tallmon, D.; Jordan S.; Taberlet P. (2003). "The Power and Promise of Population Genomics: From Genotyping to Genome Typing". ''Nature Reviews'' (4): 981-994 History Population genomics has been of interest to scientists since Darwin. Some of the first methods used for studying genetic variability at multiple loci included gel electrophoresis and restriction enzyme mapping. Previously genomics was restricted to only the study of a low amount of loci. However recent advancements in sequencing and computer storage and power have allowed for the study of hundreds of thousands of loci from populations. Analysis of this data requ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macquarie Island
Macquarie Island is an island in the southwestern Pacific Ocean, about halfway between New Zealand and Antarctica. Regionally part of Oceania and politically a part of Tasmania, Australia, since 1900, it became a Tasmanian State Reserve in 1978 and was inscribed as a UNESCO World Heritage Site in 1997. It was a part of Esperance Municipality until 1993, when the municipality was merged with other municipalities to form Huon Valley Council. The island is home to the entire royal penguin population during their annual nesting season. Ecologically, the island is part of the Antipodes Subantarctic Islands tundra ecoregion. Since 1948, the Australian Antarctic Division (AAD) has maintained a permanent base, the Macquarie Island Station, on the isthmus at the northern end of the island at the foot of Wireless Hill. The population of the base, constituting the island's only human inhabitants, usually varies from 20 to 40 people over the year. A heliport is located nearby. In Septemb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lord Howe Island
Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland Port Macquarie, northeast of Sydney, and about southwest of Norfolk Island. It is about long and between wide with an area of , though just of that comprise the low-lying developed part of the island. Along the west coast is a sandy semi-enclosed sheltered coral reef lagoon. Most of the population lives in the north, while the south is dominated by forested hills rising to the highest point on the island, Mount Gower (). The Lord Howe Island Group comprises 28 islands, islets, and rocks. Apart from Lord Howe Island itself, the most notable of these is the volcanic and uninhabited Ball's Pyramid about to the southeast of Howe. To the north lies a cluster of seven small uninhabited islands called the Admiralty Group. The first repo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tasmania
) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_date = Colony of Tasmania , established_title2 = Federation , established_date2 = 1 January 1901 , named_for = Abel Tasman , demonym = , capital = Hobart , largest_city = capital , coordinates = , admin_center = 29 local government areas , admin_center_type = Administration , leader_title1 = Monarch , leader_name1 = Charles III , leader_title2 = Governor , leader_name2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continents of Asia and Oceania in the west and the Americas in the east. At in area (as defined with a southern Antarctic border), this largest division of the World Ocean—and, in turn, the hydrosphere—covers about 46% of Earth's water surface and about 32% of its total surface area, larger than Earth's entire land area combined .Pacific Ocean . '' Britannica Concise.'' 2008: Encyclopædia Britannica, Inc. The centers of both the |
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