The combined effects of multiple genes can produce normal distributions for quantitative traits (A)one locus (C) three loci AABbcC AAbbCc AAbbcc AaBBcc aaBBCC AaBbcc aaBBCc AAbbCc AabbCc AabbCC AABBcc aaBBcc aaBbCC AaBbCC a BbCc AaBbCc AaBBCc Aabbcc aabbcc AABbCC AABBCc aaBbcc AAbbCc aaDo AaBBCC aabbcc AABBCC 708090100110120130 708090100110120130 (B)two loci (D) many loci 8 aab 708090100110120130 708090100110120130The combined effects of multiple genes can produce normal distributions for quantitative traits