A large-scale mutation is a mutation that results in changes to a large section of a DNA strand.
Large-scale mutations normally occur during chromosomal division and segregation.
Small scale mutations, on the other hand, normally occur during DNA replication.
Large-scale mutations often come about during homologous recombination in meiosis (the production of sperm and eggs). If homologous recombination is unequal, a large section of the chromosome may be lost or gained.
Large-scale mutations appear to have had a greater effect on evolution, when compared to small scale mutations.
Duplications of Hox genes is thought to have had a significant effect on the evolution of animals. These genes code for an organism's structure, such as the location of limbs.
Extra copies of entire genes allow the organism to evolve new functions without losing existing functions.