"Genetic load is an idea that started with J.B.S Haldane, who pointed out that you can’t make an omelette without breaking eggs! If you are going to produce evolutionary change by natural selection you have to have winners but you also have to have losers. Those less fit losers, who have to undergo selected death or a reduction in fertility in order for the genetic change to happen by selection, will impose a genetic load on their population because of their reduced fitness."

Linda Partridge