Howard Hughes Medical Institute: Evolution, Constant Change on Dvd The Howard Hughes Medical Institute has performed a great service in getting experts from various scientific fields to give lectures free to the public. In this DVD, evolutionary biologists David Kingsley and Sean Carroll each give two lectures on evolution. I especially liked Carroll's lectures. He eloquently explains how, in each generation of a particular species, there are genetic "copying errors" that lead to random mutations, and those whose random mutations are best suited to the environment are the ones who survive and pass pn the new genetic makeup. He uses the example of brown-furred rodents living on black rock. The ones who had a mutation in the gene controlling fur color, become black-furred, would have an advantage of not getting preyed on. I highly recommend this DVD to understand an essential facet of modern science. dvd58-00055-vg Ws or Fs All used disks are professionally refurbished and test played before shipping and will play well in most machines. Disc's are also repackaged (labeled refurbished).