Variation: evolution's white hot furnace?

From the third in our "Issue of the month" series: "We may need to go back to that old notion of evolution being driven by variation.... The bad news is, if evolution consists of only the creation of new variation, and no selection, then variations must come as improvements ready to use, and that seems to amount to intelligent design. Whether or not that’s a problem depends on how you feel about intelligent design. Apart from that, though, locating the white hot furnace that drives evolution in whatever process generates variation seems a good idea."  More...