Read the full story: http://bit.ly/1MJQ82P High-speed video of hand-made models of winged seeds, showing how a single-winged seed (left) autorotates like a helicopter, which slows its descent, while double-winged seeds do not. The longer a seed remains airborne, the greater chance of wind dispersal. The whirling, winged seeds of today’s conifers are an engineering wonder and, as University of California, Berkeley, scientists show, a result of about 270 million years of evolution by trees experimenting with the best way to disperse their seeds. Whirling, or helicoptering, keeps a seed aloft longer, increasing the chance that a gust of wind will carry a seed to a clearing where it can sprout and grow unimpeded by competitors. “Winged seeds may have contributed to the success of these conifers,” said paleobotanist Cindy Looy, an assistant professor of integrative biology at UC Berkeley, a member of the Berkeley Initiative for Global Change Biology (BiGCB) and a curator with UC Berkeley’s Museum of Paleontology. Video by Roxanne Makasdjian and Phil Ebiner; footage by Robert Stevenson, Dennis Evangelista and Cindy Looy http://www.berkeley.edu http://www.facebook.com/UCBerkeley http://twitter.com/UCBerkeley ...

eCHEM 1A: Online General Chemistry College of Chemistry, University of California, Berkeley http://chemistry.berkeley.edu/echem1a Curriculum and ChemQuizzes developed by Dr. Mark Kubinec and Professor Alexander Pines Chemical Demonstrations by Lonnie Martin Video Production by Jon Schainker and Scott Vento Developed with the support of The Camille & Henry Dreyfus Foundation

Biology 1B, 001 - Spring 2014 Creative Commons 3.0: Attribution-NonCommercial-NoDerivs

Chem 1A, 002 - Spring 2013 Creative Commons 3.0: Attribution-NonCommercial-NoDerivs