- 行业: Education
- Number of terms: 12355
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Founded in 1946, Palomar College is a public two-year community college in the city of San Marcos, located in north San Diego County, California. Palomar offers over 300 associate degree, certificate programs and is designated by the U.S. Department of Education as an Hispanic-Serving Institution ...
Два больших лобных долей в верхней части мозга которые составляют около 85% от его веса в современные люди. Наши высокого уровня психических функций, речи и обработки сложной информации, происходят в головном мозге. Коры головного мозга, или внешняя поверхность, глубоко замысловатого. Около 2/3 поверхности лежит человеческий мозг в этих складок. Количество коре складной и впоследствии площадь поверхности головного мозга, увеличение как люди эволюционировали от Homo habilis Homo erectus и, в конечном счете, Homo sapiens.
Industry:Anthropology
Неспособность разработать в конце спинного мозга. Этот тип невральной трубки всегда приводит к смерти плода или новорожденного ребенка.
Industry:Anthropology
Поле зрения за пределами линии прямого узла. Приматы и наиболее других бинокля животных только увидеть два измерения (2-D) периферически, поскольку эти районы за пределами их перекрытие поля зрения. Смотрите стереоскопическое зрение.
Industry:Anthropology
A disease that remains at a more or less constant frequency of affected individuals in a population all of the time. Examples: hypertension, tooth decay, and malaria.
Industry:Anthropology
A genetic trait controlled by more than one allele, each of which has a frequency of 1% or greater in the population gene pool. See balanced polymorphism.
Industry:Anthropology
A radiometric dating method based on the fact that trace amounts of radioactive atoms, such as uranium and thorium, in some kinds of rock, soil, and clay produce constant low amounts of background ionizing radiation. The atoms of crystalline solids, such as pottery and rock, can be altered by this radiation. Specifically, the electrons of quartz, feldspar, diamond, or calcite crystals can become displaced from their normal positions in atoms and trapped in imperfections in the crystal lattice of the rock or clay molecules. These energy charged electrons progressively accumulate over time. When a sample is heated to high temperatures in a laboratory, the trapped electrons are released and return to their normal positions in their atoms. This causes them to give off their stored energy in the form of light impulses (photons). This light is referred to as thermoluminescence (literally "heat light"). A similar effect can be brought about by stimulating the sample with infrared light. The intensity of thermoluminescence is directly related to the amount of accumulated changes produced by background radiation, which, in turn, varies with the age of the sample and the amount of trace radioactive elements it contains.
Industry:Anthropology
A hypothesis to explain the origin of modern Homo sapiens. It proposes that the first modern humans evolved in Africa, but when they migrated into other regions they did not simply replace existing human populations. Rather, they interbred to a limited degree with late archaic humans resulting in hybrid populations.
Industry:Anthropology
A radiometric dating method based on the fact that potassium-40 in volcanic rock decays into argon-40 and calcium-40 at a known rate. The half-life of potassium-40 is approximately 1. 3 billion years. Chronometric dates are determined by measuring the amount of argon-40 in a sample. Similarly, argon-40 and argon-39 ratios can be used for chronometric dating.
Industry:Anthropology
A kind of hard, rock with a glassy opaque appearance. It was a favorite raw material for many prehistoric humans for the manufacture of tools such as knives and scraping implements.
Industry:Anthropology
