Tag: tulip tree

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Petoskey Stone Dilemma

Petoskey Stone TilesEvery part of the United States has rocks, plants, and animals that are unique to that area. Certain plants grow in abundance in various locations. In Arizona the saguaro cactus is abundant. California is home for giant redwood trees. Indiana has tulip trees. Many states have adopted an official flower, tree, bird, fossil, or rock. In Michigan, since 1965 our state rock has been the Petoskey stone.

The name comes from the city of Petoskey which got its name from an Ottawa Indian legend. Thanks to the glaciers that swept down from the north scooping up rocks and depositing them, Petoskey stones are found all over the state. When I took my earth science students to the local gravel pit, we would discover Petoskey stones mixed in with the gravel. A local jeweler would show the kids how beautiful jewelry could be made from those stones.

The Petoskey stone is a petrified tropical coral with the scientific name Hexagonaria, meaning six-sided chamber. The picture shows some tiles made from Petoskey stones, and you can see that each polyp has six sides. Mixed in with them are clams, crinoids, trilobites, fish, and cephalopods. Studies of the Petoskey stone show the coral lived on plankton which are microscopic life forms that live in warm oceans. Petoskey, Michigan is NOT a tropical paradise and the Devonian period when these life forms lived lasted a long time, so the Devonian reefs are very thick. The whole state of Michigan is a bowl with these fossils found all around the state. In the middle of the bowl are coal, oil, peat, sulfur and natural gas deposits. The dilemma is how these rock formations got to be the way they are and where they are.

Some religious folks might suggest that this is a deposit produced by the flood of Noah. The problem with that explanation is that this is not a flood deposit and is not a product of violence. Genesis 7:11 tells us that “all the fountains of the great deep were broken up and the windows of heaven were opened.” I would take my students on a field trip to the Shedd Aquarium in Chicago to see a reef display. The rocks being formed and making up the reef are identical to the ones we see in the Devonian deposit. The fossils don’t show a violent end, but instead, they show a slow, gentle formation process. Calcite, silica and other minerals have replaced the original material in the cells of the Petoskey stone animals, giving a dazzling array of colors.

When God created “the heaven and the earth” (Genesis 1:1), the Bible simply states that He did it – not how He did it. At the end of verse 1, there were Petoskey stones in Devonian reefs, and oil, gas, coal, and the other resources were being formed. A change was coming that would make the conditions of the Earth more hospitable for human life, and God knew what we would need for an advanced civilization. Having a warm ocean covering the entire state of Michigan was not an environment humans could thrive in, but it was a tool God used to prepare the resources for human life.

There is no dilemma if we take the Bible literally and accept only what it says. Locking the creation account into a denominational theological tradition does violence to the Genesis account and causes young people to question the truth of the Bible. On the other hand, as they admire the beauty of the Petoskey stone jewelry they have made, people can realize that God has done some special and beautiful things to prepare a home for us in this life.
— John N. Clayton © 2019

For more on taking Genesis literally, read “God’s Revelation in His Rocks and His Word” available free on doesgodexist.org.

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Leaf Designs to Preserve Trees

Leaf Designs to Preserve Trees
We live in a part of the world where there are many trees. We also experience heavy winds that frequently blow down human-made structures. It is interesting that healthy trees are almost never blown down. When you stop to think about it, you would expect trees to be major victims of high winds. That is not the case, and it is due to leaf designs to preserve trees.

To survive strong winds, trees need two things. The most obvious is structural support–strong, flexible branches, sturdy trunks, broad bases, and good root anchorage. A more subtle requirement is leaf designs to preserve trees. Leaves must have minimal wind drag. A fluid, such as air, flowing around an object generates drag. To minimize drag requires some streamlining to reduce the amount of friction between the fluid and the object. A highly streamlined object will usually be gently rounded upstream and elongated and pointed downstream.

For healthy trees, the leaves offer the most surface area and thus the most drag. Trees most commonly blow over when in full leaf, so leaf design is critical to the survival of the tree. Different trees have different design features, but all of them are designed to avoid destruction in a wind storm. American holly leaves have a method that involves the leaves being able to flatten themselves against each other. When the wind becomes strong, the leaves turn and lie flat significantly reducing the drag.

Tulip tree leaf design allows the leaves to roll up when the wind gets strong. The blade of the leaf points away from the stem. As the wind blows against the leaf, it forms a cone pointing upwind at the stem. The blade forms the broad area of the cone away from the wind direction. The higher the wind, the tighter the cone and the less the wind resistance. Black locust leaves similarly roll together to produce a cylinder.

Each of these designs depends on the properties of the leaf. If the leaves were too stiff, they could not assume the right geometry. The flexibility of their stems has to be high, and the surface of the leaf must be carefully designed and restricted. You can argue that natural selection does all designing and that given enough time it will select the proper shape. But remember that changes in climate mean you don’t have infinite time to apply the process.

God’s engineering wisdom gave us leaf designs to preserve trees. The leaf design allows the longest season for each tree. Sit in your backyard on a breezy day and watch what the leaves do to preserve that tree you prize so highly.
–John N. Clayton © 2018