Answer: Ptolemaic system, also called geocentric system or geocentric model, mathematical model of the universe formulated by the Alexandrian astronomer and mathematician Ptolemy about 150 CE and recorded by him in his Almagest and Planetary Hypotheses. The Ptolemaic system is a geocentric cosmology; that is, it starts by assuming that Earth is stationary and at the centre of the universe. The “natural” expectation for ancient societies was that the heavenly bodies (Sun, Moon, planets, and stars) must travel in uniform motion along the most “perfect” path possible, a circle. However, the paths of the Sun, Moon, and planets as observed from Earth are not circular. Ptolemy’s model explained this “imperfection” by postulating that the apparently irregular movements were a combination of several regular circular motions seen in perspective from a stationary Earth.
Explanation:
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Genetic drift is defined as a shift in the allelic frequency of a population. This can be caused by natural selection which is the differential survival and reproduction of individuals across a population due to differences in phenotype. Natural selection favors particular traits in a population hence these individuals are able to reproduce while the individuals with disadvantageous traits will pass their genes to succeeding generations. This way the allelic frequency of succeeding generation will be diferent from that of the parent population.
Endorphins are brain chemicals
known as neurotransmitters which are released when the body feels a certain
amount of stress and pain. Endorphins alter the communication of pain in the
body by interacting with the opiate receptors and blocking the synapse so that signals
cannot be sent to the brain in order to reduce an individual perception of pain.
