Genetic linkage can be explained by the Bateson, Saunders, and Punnett experiment which included observing the phenotypes and genotypes of plants with characteristics like color and shape.
Genetic linkage is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction. Genetic linkage is the most prominent exception to Gregor Mendel's Law of Independent Assortment. Gregor Mendel's Law of Independent Assortment states that every trait is inherited independently of every other trait. But shortly after Mendel's work was rediscovered, exceptions to this rule were found. In 1905, the British geneticists William Bateson, Edith Rebecca Saunders and Reginald Punnett cross-bred pea plants in experiments similar to Mendel's. Bateson, Saunders, and Punnett experiment Purple, long (P_L_) Purple, round (P_ll) Red, long (ppL_) Red, round (ppll) 284 21 21 55 Their experiment revealed linkage between the P and L alleles and the p and l alleles. 
