 In 1947 , the microbiologist Joshua Lederberg showed that bacteria — which had been assumed to reproduce only asexually through binary fission — are capable of genetic recombination , which is more similar to sexual reproduction . This work established E. coli as a model organism in genetics , and helped Lederberg win the 1958 Nobel Prize in Physiology or Medicine . Building on studies in fungi , in 1964 Robin Holliday proposed a model for recombination in meiosis which introduced key details of how the process can work , including the exchange of material between chromosomes through Holliday junctions . In 1983 , Jack Szostak and colleagues presented a model now known as the DSBR pathway , which accounted for observations not explained by the Holliday model . During the next decade , experiments in Drosophila , budding yeast and mammalian cells led to the emergence of other models of homologous recombination , called SDSA pathways , which do not always rely on Holliday junctions . 
