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Southern Tigrina
''Leopardus guttulus'', the southern tigrina or southern tiger cat, is a small wild cat species native to Brazil, Argentina and Paraguay. Taxonomy ''Felis guttula'' was the scientific name used in 1872 by Reinhold Hensel when he described a tiger cat from the jungles of the Rio Grande do Sul in southern Brazil. It was long considered to be a subspecies of the oncilla (''Leopardus tigrinus''). It was recognized as a distinct species in 2013. It is closely related to Geoffroy's cat (''L. geoffroyi''), with which it reportedly interbreeds in southern Brazil. Characteristics The southern tigrina has a yellowish-ochre coat, patterned with open black rosettes. It is slightly darker than the oncilla, has a larger rosette pattern, and a slightly shorter tail. However, it is extremely difficult to distinguish between the two species by appearance alone, since more genetic variation tends to occur within each species, than between the two species. An adult southern tigrina weighs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Rainforest
Tropical rainforests are dense and warm rainforests with high rainfall typically found between 10° north and south of the Equator. They are a subset of the tropical forest biome that occurs roughly within the 28° latitudes (in the torrid zone between the Tropic of Cancer and Tropic of Capricorn). Tropical rainforests are a type of tropical moist broadleaf forest, that includes the more extensive seasonal tropical forests. True rainforests usually occur in tropical rainforest climates where no dry season occurs; all months have an average precipitation of at least . Seasonal tropical forests with tropical monsoon climate, tropical monsoon or tropical savanna climate, savanna climates are sometimes included in the broader definition. Tropical rainforests ecosystems are distinguished by their consistent, high temperatures, exceeding monthly, and substantial annual rainfall. The abundant rainfall results in nutrient-poor, leached soils, which profoundly affect the flora and fau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Last Glacial Maximum
The Last Glacial Maximum (LGM), also referred to as the Last Glacial Coldest Period, was the most recent time during the Last Glacial Period where ice sheets were at their greatest extent between 26,000 and 20,000 years ago. Ice sheets covered much of Northern North America, Northern Europe, and Asia and profoundly affected Earth's climate by causing a major expansion of deserts, along with a large drop in sea levels. Based on changes in position of ice sheet margins dated via cosmogenic nuclide, terrestrial cosmogenic nuclides and radiocarbon dating, growth of ice sheets in the southern hemisphere commenced 33,000 years ago and maximum coverage has been estimated to have occurred sometime between 26,500 years ago and 20,000 years ago. After this, deglaciation caused an abrupt rise in sea level. Decline of the West Antarctica ice sheet occurred between 14,000 and 15,000 years ago, consistent with evidence for another abrupt rise in the sea level about 14,500 years ago. Glacier fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. The process of evolution has given rise to biodiversity at every level of biological organisation. The scientific theory of evolution by natural selection was conceived independently by two British naturalists, Charles Darwin and Alfred Russel Wallace, in the mid-19th century as an explanation for why organisms are adapted to their physical and biological environments. The theory was first set out in detail in Darwin's book ''On the Origin of Species''. Evolution by natural selection is established by observable facts about living organisms: (1) more offspring are often produced than can possibly survive; (2) phenotypic variatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecology
Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere levels. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history. Ecology is a branch of biology, and is the study of abundance (ecology), abundance, biomass (ecology), biomass, and distribution of organisms in the context of the environment. It encompasses life processes, interactions, and adaptations; movement of materials and energy through living communities; ecological succession, successional development of ecosystems; cooperation, competition, and predation within and between species; and patterns of biodiversity and its effect on ecosystem processes. Ecology has practical applications in fields such as conservation biology, wetland management, natural resource m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deforestation
Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. About 31% of Earth's land surface is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, with half of that loss occurring in the last century. Between 15 million to 18 million hectares of forest, an area the size of Bangladesh, are destroyed every year. On average 2,400 trees are cut down each minute. Estimates vary widely as to the extent of deforestation in the tropics. In 2019, nearly a third of the overall tree cover loss, or 3.8 million hectares, occurred within humid tropical primary forests. These are areas of mature rainforest that are especially important for biodiversity and carbon storage. The direct cause of most deforestation is agriculture by far. More than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Loss
Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease in biodiversity and Abundance (ecology), species numbers. Habitat destruction is in fact the leading cause of biodiversity loss and species extinction worldwide. Humans contribute to habitat destruction through the Exploitation of natural resources, use of natural resources, agriculture, industrial production and urbanization (urban sprawl). Other activities include mining, logging and trawling. Environmental factors can contribute to habitat destruction more indirectly. Geological processes, climate change, introduced species, introduction of invasive species, ecosystem nutrient depletion, water pollution, water and noise pollution are some examples. Loss of habitat can be preceded by an initial habitat fragmentation. Fragmentation and lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavy
Caviidae, the cavy family, is composed of rodents native to South America and includes the domestic guinea pig, wild cavies, and the largest living rodent, the capybara. They are found across South America in open areas from moist savanna to thorn forests or scrub desert. This family of rodents has fewer members than most other rodent families, with 19 species in seven genera in three subfamilies. Characteristics With the exception of the maras, which have a more rabbit-like appearance, caviids have short, heavy bodies and large heads. Most have no visible tails. They range in size from the smaller cavies at 22 cm in body length, and 300 grams in weight, up to the capybara, the largest of all rodents at 106 to 134 cm in length, and body weights of 35 to 66 kilograms. Even larger forms existed in the Pliocene, such as '' Phugatherium'', which was about the size of a tapir. They are herbivores, eating tough grasses or softer leaves, depending on species. The d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Introgression
Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Introgression is a long-term process, even when artificial; it may take many hybrid generations before significant backcrossing occurs. This process is distinct from most forms of gene flow in that it occurs between two populations of different species, rather than two populations of the same species. Introgression also differs from simple Hybridization (biology), hybridization. Simple hybridization results in a relatively even mixture; gene and allele frequencies in the first generation will be a uniform mix of two parental species, such as that observed in mules. Introgression, on the other hand, results in a complex, highly variable mixture of genes, and may only involve a minimal percentage of the donor genome. Definition Introgression or i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interbreeding
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different varieties, subspecies, species or genera through sexual reproduction. Generally, it means that each cell has genetic material from two different organisms, whereas an individual where some cells are derived from a different organism is called a chimera. Hybrids are not always intermediates between their parents such as in blending inheritance (a now discredited theory in modern genetics by particulate inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductively isolated by strong barriers to hybridization, which include genetic and morpholo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pampas Cat
The Pampas cat (''Leopardus colocola'') is a small wild cat native to South America. It is listed as Near Threatened on the IUCN Red List as habitat conversion and destruction may cause the population to decline in the future. It is named after the Pampas, but occurs in grassland, shrubland, and dry forest at elevations up to . There was a proposal to divide the Pampas cat into three distinct species, based primarily on differences in pelage colour/pattern and cranial measurements. Accordingly, three species were recognised in the 2005 edition of ''Mammal Species of the World'': the colocolo (''L. colocolo''), the Pantanal cat (''L. braccatus''), and the Pampas cat (''L. pajeros'') with a more restricted definition. This split at species level was not supported by subsequent phylogeographic analysis, although some geographical substructure was recognised, and some authorities continue to recognise the Pampas cat as a single species. In the 2017 revision of fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Savannah
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. Four savanna forms exist; ''savanna woodland'' where trees and shrubs form a light canopy, ''tree savanna'' with scattered trees and shrubs, ''shrub savanna'' with distributed shrubs, and ''grass savanna'' where trees and shrubs are mostly nonexistent.Smith, Jeremy M.B.. "savanna". Encyclopedia Britannica, 5 Sep. 2016, https://www.britannica.com/science/savanna/Environment. Accessed 17 September 2022. Savannas maintain an open canopy despite a high tree density. It is often believed that savannas feature widely spaced, scattered trees. However, in many savannas, tree densities are higher and trees are more regularly spaced than in forests.Manoel Cláudio da S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
