Mendelian inheritance
![Gregor Mendel, the German-speaking Augustinian monk who founded the modern science of genetics.](/Images/godic/202501/26/Gregor_Mendel4022.png")
![A Punnett square for one of Mendel's pea plant experiments.](/Images/godic/202501/26/Punnett_square_mendel_flowers.svg4022.png")
![Figure 1 Dominant and recessive phenotypes.(1) Parental generation.(2) F1 generation.(3) F2 generation. Dominant (red) and recessive (white) phenotype look alike in the F1 (first) generation and show a 3:1 ratio in the F2 (second) generation.](/Images/godic/202501/26/Mendelian_inheritance.svg4022.png")
![Figure 2 Dihybrid cross. The phenotypes of two independent traits show a 9:3:3:1 ratio in the F2 generation. In this example, coat color is indicated by B (brown, dominant) or b (white), while tail length is indicated by S (short, dominant) or s (long). When parents are homozygous for each trait (SSbb and ssBB), their children in the F1 generation are heterozygous at both loci and only show the dominant phenotypes (SsbB). If the children mate with each other, in the F2 generation all combinations of coat color and tail length occur: 9 are brown/short (purple boxes), 3 are white/short (pink boxes), 3 are brown/long (blue boxes) and 1 is white/long (green box).](/Images/godic/202501/26/Dihybrid_cross.svg4022.png")
Mendelian inheritance is inheritance of biological features that follows the laws proposed by Gregor Johann Mendel in 1865 and 1866 and re-discovered in 1900. It was initially very controversial. When Mendel's theories were integrated with the Boveri–Sutton chromosome theory of inheritance by Thomas Hunt Morgan in 1915, they became the core of classical genetics while Ronald Fisher combined them with the theory of natural selection in his 1930 book The Genetical Theory of Natural Selection, putting evolution onto a mathematical footing and forming the basis for Population genetics and the modern evolutionary synthesis.