Genetic Variation and Evolution by Selection

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This chapter covers the variations of selection. Selection is a process, a description of how genes that produce better adaptations become more frequent over time. Species don’t try to adapt to their environment. Adaptation to the environment is inevitable if a species has the right kind of genetic variation. (pg. 117) The thought that “everything happens by chance” is essentially wrong. Evolution by selection is a combination of randomness and lawfulness. First a “random” process is the occurrence of mutations that generate an array of genetic variants, both good and bad; and then a “lawful” process (natural selection) that creates these variations. (pg.118) DNA is random, and this shows in humans and animals. For example, a humans parents …show more content…

Sexual selection comes in two forms. One, is direct competition between males for access to females. The other is through the females’ choice among possible mates. (pg. 148) In both types of sexual selection, the males compete for the females. The classic sexual selection arguments that Darwin first presented, were improved when genetics discovered how significant sexual recombination was to genetic variability and speciation. In our class discussion we were asked if animals and humans selected their partners in different ways. I agreed as well as disagreed that we are different in our selection. Humans and animals essentially need the same things, and when looking for a partner there isn’t much of a difference. We all look for the partner with the physical aspects that appeal to another, and for protection, the strongest is typically the best mate in both animal and human worlds. But for humans, emotions come into play, and we also chose on personality. One can have all of the qualifications that are “necessary” in the choosing of a mate, but if their personality does not cohabitate with the other party member, they will not be chosen for a lifelong relationship. Nonetheless, emotional choses may be the only true difference we have to that of

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