He further deduced that local environmental forces were more significant in shaping the color patterns shown by the garter snakes than shared common ancestry .
He further concluded all morphologically based subspecies in the western U.S. to be subject to revision .
He further deduced that local environmental forces were more significant in shaping the color patterns shown by the garter snakes than shared common ancestry , and concluded all morphologically based subspecies in the western U.S. to be subject to revision .