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Arboreal Theory
The arboreal theory claims that primates evolved from their ancestors by adapting to arboreal life.Sussman, R. W. (1991)Primate origins and the evolution of angiosperms American Journal of Primatology, 23(4), 209-223. It was proposed by Grafton Elliot Smith (1912), a neuroanatomist who was chiefly concerned with the emergence of the primate brain. Primates are thought to have developed several of their traits and habits initially while living in trees. One key component to this argument is that primates relied on sight over smell. They were able to develop a keen sense of depth perception, perhaps because of the constant leaping that was necessary to move about the trees. Primates also developed hands and feet that were capable of grasping. This was also a result of arboreal life, which required a great deal of crawling along branches, and reaching out for fruit and other food. These early primates were likely to have eaten foods found in trees, such as flowers, fruits, berri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primate
Primates are a diverse order (biology), order of mammals. They are divided into the Strepsirrhini, strepsirrhines, which include the lemurs, galagos, and lorisids, and the Haplorhini, haplorhines, which include the Tarsiiformes, tarsiers and the Simiiformes, simians (monkeys and apes, the latter including humans). Primates arose 85–55 million years ago first from small Terrestrial animal, terrestrial mammals, which adapted to living in the trees of tropical forests: many primate characteristics represent adaptations to life in this challenging environment, including large brains, visual acuity, color vision, a shoulder girdle allowing a large degree of movement in the shoulder joint, and dextrous hands. Primates range in size from Madame Berthe's mouse lemur, which weighs , to the eastern gorilla, weighing over . There are 376–524 species of living primates, depending on which classification is used. New primate species continue to be discovered: over 25 species were d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arboreal
Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose numerous mechanical challenges to animals moving through them and lead to a variety of anatomical, behavioral and ecological consequences as well as variations throughout different species.Cartmill, M. (1985). Climbing. In ''Functional Vertebrate Morphology'', eds. M. Hildebrand D. M. Bramble K. F. Liem and D. B. Wake, pp. 73–88. Cambridge: Belknap Press. Furthermore, many of these same principles may be applied to climbing without trees, such as on rock piles or mountains. Some animals are exclusively arboreal in habitat, such as the tree snail. Biomechanics Arboreal habitats pose numerous mechanical challenges to animals moving in them, which have been solved in diverse ways. These challenges include moving on narrow branches, mov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grafton Elliot Smith
Sir Grafton Elliot Smith (15 August 1871 – 1 January 1937) was an Australian- British anatomist, Egyptologist and a proponent of the hyperdiffusionist view of prehistory. He believed in the idea that cultural innovations occur only once and that they spread geographically. Based on this, he traced the origins of many cultural and traditional practices across the world, including the New World, to ideas that he believed came from Egypt and in some instances from Asia. An expert on brain anatomy, he was one of the first to study Egyptian mummies using radiological techniques. He took an interest in extinct humanoids and was embroiled in controversy over the authenticity of the Piltdown Man. Professional career Smith was born in Grafton, New South Wales to Stephen Sheldrick Smith who had moved to Australia from London in 1860 and Mary Jane, née Evans. He received his early education from Grafton Public School where his father was headmaster. When the family moved to Sydney i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trait (biology)
A phenotypic trait, simply trait, or character state is a distinct variant of a phenotypic characteristic of an organism; it may be either inherited or determined environmentally, but typically occurs as a combination of the two.Lawrence, Eleanor (2005) ''Henderson's Dictionary of Biology''. Pearson, Prentice Hall. For example, having eye color is a ''character'' of an organism, while blue, brown and hazel versions of eye colour are ''traits''. The term ''trait'' is generally used in genetics, often to describe phenotypic expression of different combinations of alleles in different individual organisms within a single population, such as the famous purple vs. white flower coloration in Gregor Mendel's pea plants. By contrast, in systematics, the term is ''character state'' is employed to describe features that represent fixed diagnostic differences among taxa, such as the absence of tails in great apes, relative to other primate groups. Definition A phenotypic trait i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habituation
Habituation is a form of non-associative learning in which an innate (non-reinforced) response to a stimulus decreases after repeated or prolonged presentations of that stimulus. Responses that habituate include those that involve the intact organism (e.g., full-body startle response) or those that involve only components of the organism (e.g., habituation of neurotransmitter release from ''in vitro'' Aplysia sensory neurons). The broad ubiquity of habituation across all biologic phyla has resulted in it being called "the simplest, most universal form of learning...as fundamental a characteristic of life as DNA." Functionally-speaking, by diminishing the response to an inconsequential stimulus, habituation is thought to free-up cognitive resources to other stimuli that are associated with biologically important events (i.e., punishment/reward). For example, organisms may habituate to repeated sudden loud noises when they learn these have no consequences. A progressive decline of a ... [...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 causes for alteration, lack, or disturbance to a normal sense of smell, and can include damage to the nose or smell receptors, or central problems affecting the brain. Some causes include upper respiratory infections, traumatic brain injury, and neurodegenerative disease. History of study Early scientific study of the sense of smell includes the extensive doctoral dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depth Perception
Depth perception is the ability to perceive distance to objects in the world using the visual system and visual perception. It is a major factor in perceiving the world in three dimensions. Depth perception happens primarily due to stereopsis and accommodation of the eye. Depth sensation is the corresponding term for non-human animals, since although it is known that they can sense the distance of an object, it is not known whether they perceive it in the same way that humans do. Depth perception arises from a variety of depth cues. These are typically classified into binocular cues and monocular cues. Binocular cues are based on the receipt of sensory information in three dimensions from both eyes and monocular cues can be observed with just one eye. Binocular cues include retinal disparity, which exploits parallax and vergence. Stereopsis is made possible with binocular vision. Monocular cues include relative size (distant objects subtend smaller visual angles than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each "hand" and fingerprints extremely similar to human fingerprints) are often described as having "hands" instead of paws on their front limbs. The raccoon is usually described as having "hands" though opposable thumbs are lacking. Some evolutionary anatomists use the term ''hand'' to refer to the appendage of digits on the forelimb more generally—for example, in the context of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand. The human hand usually has five digits: four fingers plus one thumb; these are often referred to collectively as five fingers, however, whereby the thumb is included as one of the fingers. It has 27 bones, not including the sesamoid bone, the number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. The word diet often implies the use of specific intake of nutrition for health or weight-management reasons (with the two often being related). Although humans are omnivores, each culture and each person holds some food preferences or some food taboos. This may be due to personal tastes or ethical reasons. Individual dietary choices may be more or less healthy. Complete nutrition requires ingestion and absorption of vitamins, minerals, essential amino acids from protein and essential fatty acids from fat-containing food, also food energy in the form of carbohydrate, protein, and fat. Dietary habits and choices play a significant role in the quality of life, health and longevity. Health A healthy diet can improve and maintain health, which can include aspects of mental and physical health. Specific diets, such as the DASH diet, can be used in treatment and management of chronic conditions. Die ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenozoic
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configuration of continents. It is the latest of three geological eras since complex life evolved, preceded by the Mesozoic and Paleozoic. It started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor. The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammalsthe eutherians (placentals) in the northern hemisphere and the metatherians (marsupials, now mainly restricted to Australia) in the southern hemisphere. The extinction of many groups allowed mammals and birds to greatly diversify so tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theories
A theory is a rational type of abstract thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking is often associated with such processes as observational study or research. Theories may be scientific, belong to a non-scientific discipline, or no discipline at all. Depending on the context, a theory's assertions might, for example, include generalized explanations of how nature works. The word has its roots in ancient Greek, but in modern use it has taken on several related meanings. In modern science, the term "theory" refers to scientific theories, a well-confirmed type of explanation of nature, made in a way consistent with the scientific method, and fulfilling the criteria required by modern science. Such theories are described in such a way that scientific tests should be able to provide empirical support for it, or empirical contradiction (" falsify") of it. Scientific theories are the most reliable, rigorous, and comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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