The beauty of autumn’s brilliant colors is an amazing testimony to the creative wisdom of God as well as an expression of His love of beauty. The colors of fall are caused by several pigments and the interaction of sunlight and sugar.
Most of us know that chlorophyll makes leaves green. When leaves receive reduced sunlight in the fall, they also have a reduced supply of nutrients and water, causing the chlorophyll to be removed. The chlorophyll masks two pigments that have different colors. Carotene is yellow, and several varieties of anthocyanins are red. Many leaves contain tannin, which is brown and is dominant in oak trees. Sunlight acting on trapped sugar also produces anthocyanins with various sparkling colors, which is why the color is so spectacular on a sunny autumn day in a maple forest.
As the days grow shorter, the reduced amount of sunlight causes a corky wall called the “abscission layer” to form between the twig and the leaf stalk. This wall will eventually break and cause the leaf to drop off in the breeze. The corky material seals off the vessels that supplied the leaf with nutrients and water and blocks any loss of sugars from the plant.
What is especially interesting is that the leaf colors are not all the same. Some vines produce spectacular colors. Poison ivy takes on a beautiful red due to a high concentration of anthocyanin. Aspen has a high concentration of carotene producing the vivid yellows which dominate the woods in the Rocky Mountains. In Michigan, we have maples, gum, aspen, and oak, giving us spectacular colors that vary from one location to another.
The colors of fall are a great testimony to the fact that God paid attention to aesthetics in the creation. If survival of the fittest were the only criteria for choosing the chemicals that allow plants to survive, it seems that there would be one best choice. Different chemicals provide a vivid, beautiful splash of color for humans to enjoy. Beauty is not part of the evolutionary model, but it speaks of God’s creativity, giving us a wonderful and beautiful world in which to live.
— John N. Clayton © 2020