Jumping Genes

On pages 136-140, Dr. Moalem discusses Barbara McClintock's lifelong study of maize genetics. Her work focused on mutations in the corn's DNA and the evolution of corn, and is related to Big Idea 1 (the process of evolution drives the diversity and unity of life). While conducting her research, McClintock discovered a phenomenon known as "jumping genes", or transposons. Jumping genes go against the previous belief that genetic mutations were random, rare, and small (point mutations).

Define jumping genes and discuss when/why they occur. How is the timing of jumping genes significant for evolution? Discuss how gamete formation in corn leads to variation in kernel phenotype and made it a good organism for McClintock to use in her research of jumping genes. Relate the pattern of inheritance of kernel phenotype to Unit 9 (Meiosis and Inheritance). After researching the current theories surrounding jumping genes, do you think it's possible that evolution is moving much faster than we've ever believed, and that individuals do in fact adapt and evolve?

(Sarah Terwilliger, sterwil3@students.d125.org)