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List Of Recently Extinct Mammals
Recently extinct mammals are defined by the International Union for Conservation of Nature (IUCN) as any mammals that have become extinct since the year 1500 CE. Since then, roughly 80 mammal species have become extinct. Extinction of taxa is difficult to confirm, as a long gap without a sighting is not definitive, but before 1995 a threshold of 50 years without a sighting was used to declare extinction. One study found that extinction from habitat loss is the hardest to detect, as this might only fragment populations to the point of concealment from humans. Some mammals declared as extinct may very well reappear. For example, a study found that 36% of purported mammalian extinction had been resolved, while the rest either had validity issues (insufficient evidence) or had been rediscovered. As of June 2023, the IUCN listed 233 mammalian species as ''critically endangered'', while 27% of all mammalian species were threatened with extinction. Conventions All species listed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinctions Africa Austrailia NAmerica Madagascar
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and recover. As a species' potential Range (biology), range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxon, Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the Fossil, fossil record) after a period of apparent absence. Over five billion species are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryotes globally, possibly many times more if microorganisms are included. Notable extinct animal species include Dinosaur, non-avian dinosaurs, Machairodontinae, saber-toothed cats, and mammoths. Through evolution, species arise through the process of specia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Degradation
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 species numbers. Habitat destruction is in fact the leading cause of biodiversity loss and species extinction worldwide. Humans contribute to habitat destruction through the 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, introduction of invasive species, ecosystem nutrient depletion, water and noise pollution are some examples. Loss of habitat can be preceded by an initial habitat fragmentation. Fragmentation and loss of habitat have become one of the most important topics of research in ecology as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overhunting
Overexploitation, also called overharvesting or ecological overshoot, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term applies to natural resources such as water aquifers, grazing pastures and forests, wild medicinal plants, fish stocks and other wildlife. In ecology, overexploitation describes one of the five main activities threatening global biodiversity. Ecologists use the term to describe populations that are harvested at an unsustainable rate, given their natural rates of mortality and capacities for reproduction. This can result in extinction at the population level and even extinction of whole species. In conservation biology, the term is usually used in the context of human economic activity that involves the taking of biological resources, or organisms, in larger numbers than their populations can withstand. The term i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Nose Syndrome
White-nose syndrome (WNS) is a fungal disease in North American bats which has resulted in the dramatic decrease of the bat population in the United States and Canada, reportedly killing millions as of 2018. The condition is named for a distinctive fungus, fungal hypha, growth around the muzzles and on the wings of hibernating bats. It was first identified from a February 2006 photo taken in a cave located in Schoharie County, New York. The syndrome has rapidly spread since then. In early 2018, it was identified in 33 U.S. states and seven Canadian provinces; plus the fungus, albeit sans syndrome, had been found in three additional states. Most cases are in the eastern half of both countries, but in March 2016, it was confirmed in a little brown bat in Washington state. In 2019, evidence of the fungus was detected in California for the first time, although no affected bats were found. The disease is caused by the fungus ''Pseudogymnoascus destructans'', which colonizes the bat's sk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food Chain
A food chain is a linear network of links in a food web, often starting with an autotroph (such as grass or algae), also called a producer, and typically ending at an apex predator (such as grizzly bears or killer whales), detritivore (such as earthworms and woodlice), or decomposer (such as fungi or bacteria). It is not the same as a food web. A food chain depicts relations between species based on what they consume for energy in trophic levels, and they are most commonly quantified in length: the number of links between a trophic consumer and the base of the chain. Food chain studies play an important role in many biological studies. Food chain stability is very important for the survival of most species. When only one element is removed from the food chain it can result in extinction or immense decreases of survival of a species. Many food chains and food webs contain a keystone species, a species that has a large impact on the surrounding environment and that can directly a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioaccumulate
Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance faster than it can be lost or eliminated by catabolism and excretion. Thus, the longer the biological half-life of a toxic substance, the greater the risk of chronic poisoning, even if environmental levels of the toxin are not very high. Bioaccumulation, for example in fish, can be predicted by models. Hypothesis for molecular size cutoff criteria for use as bioaccumulation potential indicators are not supported by data. Biotransformation can strongly modify bioaccumulation of chemicals in an organism. Toxicity induced by metals is associated with bioaccumulation and biomagnification. Storage or uptake of a metal faster than it is metabolized and excreted leads to the accumulation of that metal. The presence of various chemicals and harmful substances in the environment can be analyzed and assessed with a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistent Organic Pollutant
Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic and adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released. The effect of POPs on human and environmental health was discussed, with intention to eliminate or severely restrict their production, by the international community at the Stockholm Convention on Persistent Organic Pollutants in 2001. Most POPs are pesticides or insecticides, and some are also solvents, pharmaceuticals, and industrial chemicals. Although some POPs arise naturally (e.g. from volcanoes), most are man-made. The "dirty dozen" POPs identified by the Stockholm Convention include aldrin, chlordane, dieldrin, endrin, heptachlor, HCB, mirex, toxaphene, PCBs, DDT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterilization (medicine)
Sterilization (American and British English spelling differences, also spelled sterilisation) is any of several medical methods of permanent birth control that intentionally leaves a person unable to Human reproduction, reproduce. Sterilization methods include both surgical and non-surgical options for both males and females. Sterilization procedures are intended to be permanent; reversal is generally difficult. There are multiple ways of having sterilization done, but the two that are used most frequently are tubal ligation for women and vasectomy for men. There are many different ways tubal sterilization can be accomplished. It is extremely effective, and in the United States, surgical complications are low. With that being said, tubal sterilization is still a method that involves surgery, so there is still a danger. Women who choose tubal sterilization may have a higher risk of serious side effects, more than a man has with vasectomies. Pregnancy, Pregnancies after tubal steri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contamination
Contamination is the presence of a constituent, impurity, or some other undesirable element that renders something unsuitable, unfit or harmful for the physical body, natural environment, workplace, etc. Types of contamination Within the sciences, the word "contamination" can take on a variety of subtle differences in meaning, whether the contaminant is a solid or a liquid, as well as the variance of environment the contaminant is found to be in. A contaminant may even be more abstract, as in the case of an unwanted energy source that may interfere with a process. The following represent examples of different types of contamination based on these and other variances. Chemical contamination In chemistry, the term "contamination" usually describes a single constituent, but in specialized fields the term can also mean chemical mixtures, even up to the level of cellular materials. All chemicals contain some level of impurity. Contamination may be recognized or not and may become a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pesticide
Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all pesticide use globally. Most pesticides are used as plant protection products (also known as crop protection products), which in general protect plants from weeds, fungi, or insects. In general, a pesticide is a chemical or biological agent (such as a virus, bacterium, or fungus) that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, spread disease, or are disease vectors. Along with these benefits, pesticides also have drawbacks, such as potential toxicity to humans and other species. Definition The word pesticide derives from the Latin ''pestis'' (plagu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Fuel
A fossil fuel is a flammable carbon compound- or hydrocarbon-containing material formed naturally in the Earth's crust from the buried remains of prehistoric organisms (animals, plants or microplanktons), a process that occurs within geological formations. Reservoirs of such compound mixtures, such as coal, petroleum and natural gas, can be extracted and burnt as fuel for human consumption to provide energy for direct use (such as for cooking, heating or lighting), to power heat engines (such as steam or internal combustion engines) that can propel vehicles, or to generate electricity via steam turbine generators. Some fossil fuels are further refined into derivatives such as kerosene, gasoline and diesel, or converted into petrochemicals such as polyolefins ( plastics), aromatics and synthetic resins. The origin of fossil fuels is the anaerobic decomposition of buried dead organisms. The conversion from these organic materials to high-carbon fossil fuels is ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumber
Lumber is wood that has been processed into uniform and useful sizes (dimensional lumber), including beams and planks or boards. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, window frames). Lumber has many uses beyond home building. Lumber is referred to as timber in the United Kingdom, Australia, and New Zealand, while in other parts of the world, including the United States and Canada, the term ''timber'' refers specifically to unprocessed wood fiber, such as cut logs or standing trees that have yet to be cut. Lumber may be supplied either rough- sawn, or surfaced on one or more of its faces. ''Rough lumber'' is the raw material for furniture-making, and manufacture of other items requiring cutting and shaping. It is available in many species, including hardwoods and softwoods, such as white pine and red pine, because of their low cost. ''Finished lumber'' is supplied in standard sizes, mostly for the construction ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
