Gene mutation for color blindness found

In about 1775, a devastating typhoon swept over the island of Pingelap, a Pacific atoll that’s now part of Micronesia. Twenty people survived the storm and subsequent famine to repopulate the island. One man, however, apparently carried a genetic mutation that causes color blindness. Intermarriage among the survivors’ descendents has left about 5 percent of the island’s residents with the color blindness disease achromatopsia—all of whom trace their ancestry to this man.