Book review of Nature\'s I.Q. (Evolution)

by David Turell , Saturday, August 29, 2009, 21:11 (5363 days ago) @ David Turell

There is a section in the book on instinctual migration. It is not difficult to imagine a scenario for evolution of salmon migration. They are born as fresh water fish in tiny tributaries of rivers, go to sea for six years and travel back to the same tributary to spawn. One can imagine a process in which they ventured out into the ocean bit by bit and developed some sort of navigation system to come back to their birthplace over many favorable mutations. - But this is not true of many migrating birds. Hummingbirds in the south USA must cover over 600 miles of Gulf waters to reach Mexico, non-stop. The birds weight 0.1 ounce and must eat to double their weight before making the flight, to have enough nutrition for the journey, but only if they use favorable tail winds. The American Golden Plover does the same thing from Alaska to Hawaii, 2,200 miles non-stop. They must gain 2.5 ounces added to their 4.5 ounce bodies to have the energy to make the trip. They use V-formation in flight which acts like drafting in car racing to save energy, because the trip calculates nutritionally to require 2.9 ounces of weight gain. Both species must also navigate properly as there are no guidposts along the way. There is no way that this can develop in a step-wise manner as I can imagine for salmon. Either you make it the first time or there are no future generations. And you also have to know how much to eat in advance without knowing the distance of flight required. I can actually imagine the Hummingbirds working their way down the Gulf Coast over many generations to get to the southern Mexican coast, but the step to the one long flight; there is no way the birds could figure out how to try that. The Plovers can only make the one huge hop. There are no intermediates. This does not fit Darwin.