Barbara McClintock and the discovery of jumping genes
http://www.nature.com/scitable/topicpage/barbara-mcclintock-and-the-discovery-of-jumping-34083
Transposable elements (TEs), also known as "jumping genes" ,,, were discovered during the middle part of the twentieth century by American scientist Barbara McClintock. McClintock's work was revolutionary in that it suggested that an organism's genome is not a stationary entity, but rather it is subject to alteration and rearrangement—a concept that was met with criticism from the scientific community of the time. Eventually, however, the significance of McClintock's work became widely appreciated, and she was awarded the Nobel Prize in 1983.
Extra genomes helped plants to survive extinction event that killed dinosaurs
http://blogs.discovermagazine.com/notrocketscience/2009/03/page/2/
Sixty-five million years ago, life on Earth was sorely tested. One or more catastrophic events including a massive asteroid strike and increased volcanic activity, created wildfires on a global scale and dust clouds that cut the planet’s surface off from the sun’s vital light. The majority of animal species went extinct including, most famously, the dinosaurs. The fate of the planet’s plants is less familiar, but 60% of those also perished. What separated the survivors from the deceased? How did some species cross this so-called “K/T boundary”?
Jeffrey Fawcett form the Flanders Institute for Biotechnology thinks that the answer lies in their genomes and specifically how many copies they have. Geneticists have found that the majority of plants have duplicated their entire portfolio of genetic material at some point in their evolution. They are called “polyploids” – species with multiple copies of the same genome.
By dating these doublings, Fawcett had found that the most recent of them cluster at a specific point in geological time – 65 million years ago, at the K/T boundary. It suggests that having extra copies of their genomes on hand gave these plants the edge they needed to cope with the dramatic environmental changes that wiped out the dinosaurs and other less well-endowed species.
Sixty-five million years ago, life on Earth was sorely tested. One or more catastrophic events including a massive asteroid strike and increased volcanic activity, created wildfires on a global scale and dust clouds that cut the planet’s surface off from the sun’s vital light. The majority of animal species went extinct including, most famously, the dinosaurs. The fate of the planet’s plants is less familiar, but 60% of those also perished. What separated the survivors from the deceased? How did some species cross this so-called “K/T boundary”?
Jeffrey Fawcett form the Flanders Institute for Biotechnology thinks that the answer lies in their genomes and specifically how many copies they have. Geneticists have found that the majority of plants have duplicated their entire portfolio of genetic material at some point in their evolution. They are called “polyploids” – species with multiple copies of the same genome.
By dating these doublings, Fawcett had found that the most recent of them cluster at a specific point in geological time – 65 million years ago, at the K/T boundary. It suggests that having extra copies of their genomes on hand gave these plants the edge they needed to cope with the dramatic environmental changes that wiped out the dinosaurs and other less well-endowed species.