theory of linear arrangement of genes

The theory of the linear arrangement of genes, also known as gene mapping, posits that genes are located in a fixed, linear order on chromosomes. This concept emerged from observations that certain traits, controlled by genes on the same chromosome, tend to be inherited together, a phenomenon called linkage.123

Early experiments with fruit flies (Drosophila) by Thomas Hunt Morgan and his colleagues demonstrated that the frequency of recombination between linked genes could be used to estimate the physical distance between them on a chromosome. This led to the creation of linkage maps, which visually represent the order and relative spacing of genes along a chromosome. The number of linkage groups in an organism typically corresponds to the number of chromosomes in its sex cells. This understanding revolutionized genetics by providing a physical basis for heredity and a way to map the genetic landscape within chromosomes.124