Monohybrid cross predicts that three quarters of the F2 generation will have the dominant allele's phenotype. And the remaining quarter of the F2s will have the recessive allele's phenotype. This predicted 3:1 phenotypic ratio assumes Mendelian inheritance. This cross was originally used by biologist Gregor Mendel, who crossed two pea plants to obtain a hybrid variety and discovered the dominance relationships between alleles of several genes. Mendel has considered one alleleomorph character for his first experiment that is colour of red and white length of plant-tall and dwarf. Gregor Mendel (1822–1884) was an Austrian monk who theorized basic rules of inheritance. From
Genetics and the Origin of Species that give them a competitive advantage, and they have the best chance of surviving and procreating. The main element lacking in the theory was any mechanism that would allow organisms to pass on these favorable variations. Lacking such a mechanism, the theory of evolution faced competition from theories such as neo-Lamarckism, in which the environment acted directly on organisms, changing their structures. Darwin did not know that the monk Gregor Mendel was already working on experiments that would explain inheritance in terms of units of heredity that we now call genes. When Mendelian genetics was rediscovered by several scientists, it