population, quantitative and evolutionary genetics Albert Levan (1905–1998), Swedist geneticist, co-authored report that humans have 46 chromosomes Cyrus Levinthal (1922–1990), US molecular geneticist, DNA replication, mRNA, molecular graphics Edward B. Lewis (1918–2004), US founder of developmental genetics and Nobel Prize-winner Richard Lewontin (1929–2021), US evolutionary biologist, geneticist and social commentator C. C. Li (1912–2003), eminent Chinese American population geneticist and human geneticist Wen-Hsiung Li (born 1942), Taiwanese-American, molecular evolution, population genetics, genomics David Linder (1923–1999), US pathologist and geneticist, used G6PD as X-linked clonal tumor marker Susan Lindquist (1949–2016), US molecular biologist studying effects of protein folding and heat-shock proteins Jan Lindsten (born 1935), eminent Swedish medical geneticist, secretary general of the Nobel Assembly Fritz Lipmann (1899–1986), German-American biochemist, Nobel Prize for co-discovery of coenzyme A C. C. Little (1888–1971), US pioneer mouse geneticist, founded Jackson Laboratory in Bar Harbor, Maine Richard Losick (born 1943), US molecular biologist, RNA polymerase, gene transcription, bacterial development Herbert Lubs (born c. 1928), US internist, medical geneticist, described "marker X" (fragile X chromosome) Salvador Luria (1912–1991), Italian-American molecular biologist, Nobel Prize for bacteriophage genetics Jay Lush (1896–1982), US animal geneticist who pioneered modern scientific animal breeding Michael Lynch (born 1951), US quantitative geneticist studying evolution, population genetics, and genomics Mary F. Lyon (1925–2014), English mouse geneticist, noted X-inactivation and proposed Lyon hypothesis David T. Lykken (1928–2006), US psychologist and behavioral geneticist known for twin studies Trofim Lysenko (1898–1976), Soviet scientist, led vicious political campaign against genetics in USSR M Ellen Magenis (1925–2014), US medical geneticist and cytogeneticist, Smith–Magenis syndrome Phyllis McAlpine (1941–1998), Canadian human geneticist and gene mapper Maclyn McCarty (1911–2005), US co-discoverer that DNA is the genetic material Barbara McClintock (1902–1992), US cytogeneticist, Nobel Prize for genetic transposition William McGinnis, US molecular geneticist, found homeobox (Hox) genes responsible for basic body plan Victor A. McKusick (1921–2008), US internist and clinical geneticist, organized human genetic knowledge Colin MacLeod (1909–1972), Canadian-American co-discoverer that DNA is the genetic material Tak Wah Mak (born 1946), Chinese-Canadian molecular biologist, co-discovered human T cell receptor genes Gustave Malécot (1911–1998), French mathematician who influenced population genetics Tom Maniatis (born 1943), US molecular biologist, gene cloning, regulation of gene expression Clement Markert (1917–1999), eminent US biologist, discovered isozymes Joan Marks, US social worker, principal architect of the profession of genetic counselor Marco Marra (born 1966), Canadian scientist Richard E. Marshall (1933–2016), US paediatrician, Greig's syndrome I, Marshall–Smith syndrome John Maynard Smith