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Predator-prey Interactions
Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predation behavior varies significantly depending on the organism. Many predators, especially carnivores, have evolved distinct hunting strategies. Pursuit predation involves the active search for and pursuit of prey, whilst ambush predators instead wait for prey to present an opportunity for capture, and often use stealth or aggressive mimicry. Other predators are opportunistic or omnivorous and only practice predation occasionally. Most obligate carnivores are specialized for hunting. They may have acute s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Bear (Ursus Maritimus) With Its Prey
The polar bear (''Ursus maritimus'') is a large bear native to the Arctic and nearby areas. It is closely related to the brown bear, and the two species can Hybrid (biology), interbreed. The polar bear is the largest extant species of bear and land carnivore, with adult males weighing . The species is sexually dimorphic, as adult females are much smaller. The polar bear is white- or yellowish-furred with black skin and a thick layer of fat. It is more slender than the brown bear, with a narrower skull, longer neck and lower shoulder hump. Its teeth are sharper and more adapted to cutting meat. The paws are large and allow the bear to walk on ice and paddle in the water. Polar bears are both terrestrial and Pagophily, pagophilic (ice-living) and are considered marine mammals because of their dependence on marine ecosystems. They prefer the annual sea ice but live on land when the ice melts in the summer. They are mostly carnivorous and specialized for preying on pinniped, se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opportunism
300px, ''Opportunity Seized, Opportunity Missed'', engraving by Theodoor Galle, 1605 Opportunism is the practice of taking advantage of circumstances — with little regard for principles or with what the consequences are for others. Opportunist actions are expedient actions guided primarily by self-interested motives. The term can be applied to individual humans and living organisms, groups, organizations, styles, behaviors and trends. Opportunism or "opportunistic behaviour" is an important concept in such fields of study as biology, transaction cost economics, game theory, ethics, psychology, sociology and politics. Etymology In the early 19th century, the term "opportunist" as a noun or adjective was already known and used in several European languages, but initially, it rarely referred to political processes or to a political tendency. The English term "opportunism" is possibly borrowed originally from the Italian expression ''opportunismo''. In 19th-century Itali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-predator Adaptation
Anti-predator adaptations are mechanisms developed through evolution that assist Predation, prey organisms in their constant struggle against predators. Throughout the animal kingdom, adaptations have evolved for every stage of this struggle, namely by avoiding detection, warding off attack, fighting back, or escaping when caught. The first line of defence consists in avoiding detection, through mechanisms such as camouflage, Masquerade (biology), masquerade, apostatic selection, living underground, or nocturnality. Alternatively, prey animals may ward off attack, whether by advertising the presence of strong defences in aposematism, by mimicry, mimicking animals which do possess such defences, by deimatic behaviour, startling the attacker, by signalling theory, signalling to the predator that pursuit is not worthwhile, by distraction display, distraction, by using defensive structures such as spines, and by social animal, living in a group. Members of groups are at selfish herd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selection Pressure
Evolutionary pressure, selective pressure or selection pressure is exerted by factors that reduce or increase reproductive success in a portion of a population, driving natural selection. It is a quantitative description of the amount of change occurring in processes investigated by evolutionary biology, but the formal concept is often extended to other areas of research. In population genetics, selective pressure is usually expressed as a selection coefficient. Amino acids selective pressure It has been shown that putting an amino acid bio-synthesizing gene like ''HIS4'' gene under amino acid selective pressure in yeast causes enhancement of expression of adjacent genes which is due to the transcriptional co-regulation of two adjacent genes in Eukaryota. Antibiotic resistance Drug resistance in bacteria is an example of an outcome of natural selection. When a drug is used on a species of bacteria, those that cannot resist die and do not produce offspring, while those that s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Social Behaviour
Social behavior is behavior among two or more organisms within the same species, it encompasses any behavior in which one member affects another. Social behavior can be seen as similar to an exchange of goods, with the expectation that when you give, you will receive something similar in return. This behavior can be affected by both the qualities of the individual and the environmental (situational) factors. Therefore, social behavior arises as a result of an interaction between the two—the organism and its environment. This means that, in regards to humans, social behavior can be determined by both the individual characteristics of the person, and the situation they are in. A major aspect of social behavior is communication, which is the basis for survival and reproduction. Social behavior is said to be determined by two different processes, that can either work together or oppose one another. The dual-systems model of reflective and impulsive determinants of social behavior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intelligence
Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. It can be described as the ability to perceive or infer information and to retain it as knowledge to be applied to adaptive behaviors within an environment or context. The term rose to prominence during the early 1900s. Most psychologists believe that intelligence can be divided into various domains or competencies. Intelligence has been long-studied in humans, and across numerous disciplines. It has also been observed in the cognition of non-human animals. Some researchers have suggested that plants exhibit forms of intelligence, though this remains controversial. Etymology The word '' intelligence'' derives from the Latin nouns '' intelligentia'' or '' intellēctus'', which in turn stem from the verb '' intelligere'', to comprehend or perceive. In the M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endurance
Endurance (also related to sufferance, forbearance, resilience, constitution, fortitude, persistence, tenacity, steadfastness, perseverance, stamina, and hardiness) is the ability of an organism to exert itself and remain active for a long period of time, as well as its ability to resist, withstand, recover from and have immunity to trauma, wounds, or fatigue. The term is often used in the context of aerobic or anaerobic exercise. The definition of "long" varies according to the type of exertion – minutes for high intensity anaerobic exercise, hours or days for low intensity aerobic exercise. Training for endurance can reduce endurance strength unless an individual also undertakes resistance training to counteract this effect. When a person is able to accomplish or withstand more effort than previously, their endurance is increasing. To improve their endurance they may slowly increase the amount of repetitions or time spent; in some exercises, more repetitions t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Cat
The term "big cat" is typically used to refer to any of the five living members of the genus ''Panthera'', namely the tiger, lion, jaguar, leopard, and snow leopard. All cats descend from the ''Felidae'' family, sharing similar musculature, cardiovascular systems, skeletal frames, and behaviour. Both the cheetah and cougar differ physically from fellow big cats, and to a greater extent, other small cats. As obligate carnivores, big cats are considered apex predators, topping their food chain without natural predators of their own. Native ranges include the Americas, Africa, and Asia; the ranges of the leopard and tiger also extend into Europe, specifically in Russia. Species *Family ''Felidae'' ** Subfamily '' Pantherinae'' *** Genus ''Panthera'' **** Tiger (''Panthera tigris'') **** Lion (''Panthera leo'') **** Jaguar (''Panthera onca'') **** Leopard (''Panthera pardus'') **** Snow leopard (''Panthera uncia'') ** Subfamily '' Felinae'' *** Genus '' Acinonyx'' **** Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Strength
Physical strength is the measure of an individual's exertion of force on physical objects. Increasing physical strength is the goal of strength training. Overview An individual's physical strength is determined by two factors: the cross-sectional area of muscle fibers recruited to generate force and the intensity of the recruitment. Individuals with a high proportion of Muscle fibre#Type I, type I slow twitch muscle fibers will be relatively weaker than a similar individual with a high proportion of Muscle fibre#Type II, type II fast twitch fibers, but would have greater endurance. The genetic inheritance of muscle fiber type sets the outermost boundaries of physical strength possible (barring the use of enhancing agents such as testosterone), although the unique position within this envelope is determined by training. Individual muscle fiber ratios can be determined through a muscle biopsy. Other considerations are the ability to recruit muscle fibers for a particular activity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claw
A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or Arthropod leg, tarsus for gripping a surface as they walk. The pincers of crabs, lobsters and scorpions, more formally known as their chelae, are sometimes called claws. A true claw is made of a hard protein called keratin. Claws are used to catch and hold prey in carnivorous mammals such as cats and dogs, but may also be used for such purposes as digging, climbing trees, self-defense and Personal grooming, grooming, in those and other species. Similar appendages that are flat and do not come to a sharp point are called nail (anatomy), nails instead. Claw-like projections that do not form at the end of digits but spring from other parts of the foot are properly named Spur (zoology), spurs. Tetrapods In tetrapods, claws are made of keratin and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prey Detection
Prey detection is the process by which predators are able to detect and locate their prey via sensory system, sensory signals. This article treats predation in its broadest sense, i.e. where one organism eats another. Evolutionary struggle and prey defenses Predators are in an evolutionary arms race with their prey, for which advantageous mutations are constantly preserved by natural selection. In turn, predators, too, are subject to such selective pressure, those most successful in locating prey passing on their genes in greater number to the next generation's gene pool. Adaptations of prey that allow them to avoid predators are widespread, those that make them hard to find being collectively known as crypsis. Crypsis may involve temporal evasion such as nocturnality, behavioral methods such as hiding, and non-behavioral adaptations such as camouflage. Antipredator adaptations include methods other than crypsis, such as aposematism and the ability to fight. Often behavioral and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfaction
The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, it occurs when an odor binds to a receptor within the nasal cavity, transmitting a signal through the olfactory system. Glomeruli aggregate signals from these receptors and transmit them to the olfactory bulb, where the sensory input will start to interact with parts of the brain responsible for smell identification, memory, and emotion. There are many different things which can interfere with a normal sense of smell, including damage to the nose or smell receptors, anosmia, upper respiratory infections, traumatic brain injury, and neurodegenerative disease. History of study Early scientific study of the sense of smell includes the extensive doctoral dissertation of Eleanor Gamble, published in 1898, which compared olfactory to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
