The protein, hemoglobin, is an essential component of humans and other vertebrates. Contained in red blood cells, hemoglobin serves as the oxygen-carrier in blood. Each human has over 60 octillion (60,000,000,000,000,000,000) hemoglobin molecules. Each hemoglobin molecule is made up of two twisted chains of 574 amino acids each linked together in a specific order. There are thousands of different types of amino acids, however, only 20 of these types of amino acids are used in living organisms. This means that only these 20 are used in making hemoglobin and each amino acid must be linked up in the right order.

If we were to take two railroad trains of 574 cars each, with 20 different colors of cars, we would have a picture of hemoglobin. In order to link the cars of the train in the proper order, we have to choose the correct color car for each position. Since there are 20 different colors of cars, this means for the first position there are 20 different choices. To properly link the first two cars, we must select from 20 different color choices for each of the two cars. 20 possible colors for the first car and 20 possible colors for the second car—20 times 20, or 400 possible color combinations just to properly link the first two cars. If we were to link up the first three cars we would have 8,000 different combinations, 20 choices for each of the three cars (20 times 20 times 20). This can also be written as 203 (20 multiplied by 20 for 3 times).

Hemoglobin has 574 'cars' or 20 raised to the 574th power (20574 possible combinations). How long would it take to assemble a train, with the colored cars in the correct order, with this many possible combinations? If you were able to do one combination every second of your life, you would run out of time. If you were able to try one combination for every second of the estimated age of the universe (15 billion years or about 1018 seconds), you would still run out of time. There is not enough time in the estimated age of the universe to try even a small fraction of the possible combinations. It would take over a quadrillion (1,000,000,000,000,000) years of trying a combination every second and still, there would not be enough time to try all the possible combinations. How could this have happened in less than 4 billion years without the help of an intelligent designer?