NOVEMBER 20, 2009 COVER An ear of Zea mays (maize) shows color variation among kernels. Maize is one of the most important crop species worldwide, a vital source of food and fuel, and a valuable model organism for genetic research. Reports starting on pages 1112 and 1115 describe the genome sequences of the B73 and Palomero Toluqueño varieties. See also the related Report (p. 1118), Brevia (p. 1078), and Perspective (p. 1071). Photo: Kate Mathis/Getty Images

Barbara McClintock

http://nobelprize.org/nobel_prizes/medicine/laureates/1983/mcclintock-autobio.html

She was the first geneticist to propose the existence of transposable elements indicating that an organism’s genome was dynamic – not static

http://www.nature.com/scitable/topicpage/Barbara-McClintock-and-the-Discovery-of-Jumping-34083 http://www.nature.com/scitable/topicpage/Transposons-The-Jumping-Genes-518

She showed that recombination of genotypes was associated with a physical exchange of chromosomes: http://www.nature.com/scitable/topicpage/Genetic-Recombination-514

http://www.nature.com/scitable/topicpage/Genetic-Recombination-514