Human evolution
is the evolutionary process leading up to the appearance of modern humans. While it began with the last common ancestor of all life, the topic usually covers only the evolutionary history of primates, in particular the genusHomo, and the emergence of Homo sapiens as a distinct species of hominids (or "great apes"). The study of human evolution involves many scientific disciplines, including physical anthropology, primatology, archaeology, ethology,linguistics, evolutionary psychology, embryology and genetics.
Genetic studies show that primates diverged from other mammals about 85 million years ago in the Late Cretaceous period, and the earliest fossils appear in the Paleocene, around 55 million years ago. The family Hominidae diverged from theHylobatidae (Gibbon) family 15-20 million years ago, and around 14 million years ago, the Ponginae (orangutans), diverged from the Hominidae family. Bipedalism is the basic adaption of the Hominin line, and the earliest bipedal Hominin is considered to be either Sahelanthropus or Orrorin, with Ardipithecus, a full bipedal, coming somewhat later. The gorilla and chimpanzee diverged around the same time, about 4-6 million years ago, and either Sahelanthropus or Orrorin may be our last shared ancestor with them. The early bipedals eventually evolved into the australopithecines and later the genusHomo.
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population
is the branch of life sciences that studies short-term and long-term changes in the size and age composition of populations, and the biological and environmental processes influencing those changes. Population dynamics deals with the way populations are affected by birth and death rates, and by immigration andemigration, and studies topics such as ageing populations or population decline.
One common mathematical model for population dynamics is the exponential growth model. With the exponential model, the rate of change of any given population is proportional to the already existing population.
videos
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