PSYC 3P37 Lecture Notes - Lecture 2: Anisogamy, Ecological Niche, Allopatric Speciation
13 Jan 2016
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One inherits units of heredity (now called genes) from both parents, these unit then blend together and are transmitted as blend to the offspring. This is a misunderstanding of the way heredity works . Created a problem for darwin"s theory: any new sport (now called mutation) will be blended away before proliferating (diluted away after a few generations) Mendel (1866) showed that units of heredity don"t blend; instead, pass intact across generations (law of segregation) We now refer to units of heredity as genes. Variation caused by mutations to genes carried in sex cells. Most mutations are harmful (or neutral), but beneficial mutations are selected. Note: evolution partly by selection, partly by random changes . A random mutation could increase in frequency just be chance (genetic drift) especially in small population, even if neutral or harmful. But its natural selection that increases the frequency of mutant genes that produce beneficial characteristics (adaptations) Sometimes an adaptation emerges suddenly via a major.
