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Urban Evolution
Urban evolution refers to the heritable genetic changes of populations in response to urban development and anthropogenic activities in urban areas. Urban evolution can be caused by non-random mating, mutation, genetic drift, gene flow, or evolution by natural selection. In the context of Earth's living history, rapid urbanization is a relatively recent phenomenon, yet biologists have already observed evolutionary change in numerous species compared to their rural counterparts on a relatively short timescale. Strong selection pressures due to urbanization play a big role in this process. Urbanization introduces distinct challenges such as altered microclimates, pollution, habitat fragmentation, and differential resource availability. These changed environmental conditions exert unique selection pressures on their inhabitants, leading to physiological and behavioral adaptations in city-dwelling plant and animal species. However, there is also discussion on whether some of these emerg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urban Area
An urban area is a human settlement with a high population density and an infrastructure of built environment. Urban areas originate through urbanization, and researchers categorize them as cities, towns, conurbations or suburbs. In urbanism, the term "urban area" contrasts to rural areas such as villages and hamlet (place), hamlets; in urban sociology or urban anthropology, it often contrasts with natural environment. The development of earlier predecessors of modern urban areas during the urban revolution of the 4th millennium BCE led to the formation of human civilization and ultimately to modern urban planning, which along with other human activities such as exploitation of natural resources has led to a human impact on the environment. Recent historical growth In 1950, 764 million people (or about 30 percent of the world's 2.5 billion people) lived in urban areas. In 2009, the number of people living in urban areas (3.42 billion) surpassed the number living in rural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urban Heat Island
Urban areas usually experience the urban heat island (UHI) effect; that is, they are significantly warmer than surrounding rural areas. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak, under Block (meteorology), block conditions, noticeably during the summer and winter. The main cause of the UHI effect is from the modification of land surfaces, while waste heat generated by energy usage is a secondary contributor. Urban areas occupy about 0.5% of the Earth's land surface but host more than half of the world's population. As a population center grows, it tends to expand its area and increase its average temperature. The term heat island is also used; the term can be used to refer to any area that is relatively hotter than the surrounding, but generally refers to human-disturbed areas. Monthly precipitation (meteorology), rainfall is greater downwind of cities, partially due to the UHI. Increases in heat within urb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Fragmentation
Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes that slowly alter the layout of the physical environment (suspected of being one of the major causes of speciation), and human activity such as land conversion, which can alter the environment much faster and causes the extinction of many species. More specifically, habitat fragmentation is a process by which large and contiguous habitats get divided into smaller, isolated patches of habitats. Definition The term habitat fragmentation includes five discrete phenomena: * Reduction in the total area of the habitat * Decrease of the interior: edge ratio * Isolation of one habitat fragment from other areas of habitat * Breaking up of one patch of habitat into several smaller patches * Decrease in the average size of each patch of habit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise Pollution
Noise pollution, or sound pollution, is the propagation of noise or sound with potential harmful effects on humans and animals. The source of outdoor noise worldwide is mainly caused by machines, transport and propagation systems.Senate Public Works Committee. ''Noise Pollution and Abatement Act of 1972''. S. Rep. No. 1160, 92nd Congress. 2nd session Poor urban planning may give rise to noise disintegration or pollution, side-by-side industrial, and residential buildings can result in noise pollution in the residential areas. Some of the main sources of noise in residential areas include loud music, transportation (traffic, rail, airplanes, etc.), lawn care maintenance, construction, electrical generators, wind turbines, explosions, and people. Documented problems associated with noise in urban environments go back as far as ancient Rome. Research suggests that noise pollution in the United States is the highest in low-income and racial minority neighborhoods, and noise pollut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mummichog
The mummichog (''Fundulus heteroclitus'') is a small killifish found along the Atlantic coast of the United States and Canada. Also known as Atlantic killifish, mummies, gudgeons, and mud minnows, these fish inhabit brackish and coastal waters including estuaries and salt marshes. The species is noted for its hardiness and ability to tolerate highly variable salinity, temperature fluctuations from , very low oxygen levels (down to 1 mg/L), and heavily polluted ecosystems. As a result, the mummichog is a popular research subject in embryological, physiological, and toxicological studies. It is also the first fish ever sent to space, aboard Skylab in 1973. Taxonomy The genus name ''Fundulus'' comes from ', meaning bottom, from the fish's habit of swimming near muddy bottoms. The species name ''heteroclitus'' means irregular or unusual. The type specimen was first described by Carl Linnaeus in 1766, from near Charleston, South Carolina. Other scientific names now considered syno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Pollution
Water pollution (or aquatic pollution) is the contamination of Body of water, water bodies, with a negative impact on their uses. It is usually a result of human activities. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants mix with these water bodies. Contaminants can come from one of four main sources. These are sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater. Water pollution may affect either surface water or groundwater pollution, groundwater. This form of pollution can lead to many problems. One is the environmental degradation, degradation of aquatic ecosystems. Another is spreading Waterborne diseases, water-borne diseases when people use polluted water for drinking or irrigation. Water pollution also reduces the ecosystem services such as drinking water provided by the Water resources, water resource. Sources of water pollution are either p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Tit
The great tit (''Parus major'') is a small passerine bird in the tit family Paridae. It is a widespread and common species throughout Europe, the Middle East, Central Asia and east across the Palearctic to the Amur River, south to parts of North Africa where it is generally resident in any sort of woodland; most great tits do not migrate except in extremely harsh winters. Until 2005 this species was lumped with numerous other subspecies. DNA studies have shown these other subspecies to be distinct from the great tit and these have now been separated as two distinct species, the cinereous tit (''Parus cinereus'') of southern Asia, and the Japanese tit (''Parus minor'') of East Asia. The great tit remains the most widespread species in the genus ''Parus''. The great tit is a distinctive bird with a black head and neck, prominent white cheeks, olive upperparts and yellow underparts, with some variation amongst the numerous subspecies. It is predominantly insectivorous in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peppered Moth
The peppered moth (''Biston betularia'') is a temperate species of Nocturnality, night-flying moth. It is mostly found in the northern hemisphere in places like Asia, Europe and North America. Peppered moth evolution is an example of population genetics and natural selection. The caterpillars of the peppered moth not only mimic the form but also the colour of a twig. Recent research indicates that the caterpillars can sense the twig's colour with their skin and match their body colour to the background to protect themselves from predators. Description The wingspan ranges from 45 mm to 62 mm (median 55 mm). It is relatively stout-bodied, with forewings relatively narrow-elongate. The wings are white, "peppered" with black, and with more-or-less distinct cross lines, also black. These transverse wing lines and "peppered" maculation (spotting) can also, in rare instances, be gray or brown; the spotting pattern, in particularly very rare cases, is sometimes a com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Contamination
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons (such as naphthalene and benzo(a)pyrene), solvents, pesticides, lead, and other heavy metals. Contamination is correlated with the degree of industrialization and intensity of chemical substance. The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapour from the contaminants, or from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting clean ups are time-consuming and expensive tasks, and require expertise in geology, hydrology, chemistry, computer m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Pollution
Air pollution is the presence of substances in the Atmosphere of Earth, air that are harmful to humans, other living beings or the environment. Pollutants can be Gas, gases like Ground-level ozone, ozone or nitrogen oxides or small particles like soot and dust. It affects both outdoor air and indoor air. Natural sources of air pollution include Wildfire, wildfires, Dust storm, dust storms, and Volcanic eruption, volcanic eruptions. Indoor air pollution is often Energy poverty and cooking, caused by the use of biomass (e.g. wood) for cooking and heating. Outdoor air pollution comes from some industrial processes, the burning of Fossil fuel, fossil fuels for electricity and transport, waste management and agriculture. Many of the contributors of local air pollution, especially the burning of fossil fuels, also cause greenhouse gas emissions that cause climate change, global warming. Air pollution causes around 7 or 8 million deaths each year. It is a significant risk factor for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiology
Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organ (biology), organs, cell (biology), cells, and biomolecules carry out chemistry, chemical and physics, physical functions in a living system. According to the classes of organisms, the field can be divided into clinical physiology, medical physiology, Zoology#Physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysics, biophysical and biochemical processes, homeostasis, homeostatic control mechanisms, and cell signaling, communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathology, pathological state'' refers to abnormality (behavior), abnormal conditions, including human diseases. ... [...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] |
