A basic undergraduate text, in Portuguese, covering classical (forward-looking) Population Genetics theory: the Hardy-Weinberg model (any number of autosomal or sex-linked genes), followed by the consequences of mutation, natural selection, inbreeding, sub-division, migration, and random genetic drift. Coalescent-based developments are conspicuous by their absence. Clear biological questions are asked, that motivate (and require) the mathematics. Almost all equations are thoroughly derived step-by-step using simple algebra. This results in equation-laden pages, but the text thoroughly explains and discusses the assumptions and implications of all key equations. The 2014 edition is slightly expanded and thoroughly revised.