Yesterday, I was talking with a friend about politics and evolution. He asked, “Creationism is pretty harmless, though, right? It doesn’t really hurt anyone.”
I suppose for most people, the question “Do you believe in evolution?” seems to matter about as much as the question, “Do you believe in Bigfoot?” Bigfoot might be there, or he might not be, but whether he is or isn’t doesn’t make much difference in their lives. But even though most people may not think about this issue much, I think Creationism does hurt people, and in two main ways. First, evolutionary theory has many practical applications for all sorts of different topics: geology, medicine, agriculture, economics, advertising, mate choice, and pretty much anything else that has anything to do with biology. A proper understanding of evolution can help people make better decisions regarding all sorts of practical matters. Creationism hurts people by closing their minds to this useful information. Second, evolutionary theory opens the doors to a profound and beautiful view of the world. Creationism hurts people by robbing them of a deeper understanding of what the world is, and how it came to be.
By Creationism, I mean the belief that God created the world suddenly, pretty much as it is now, some time in the recent past. This is different from, say, theistic evolution, advocated by people like the great dinosaur scientist Robert Bakker (who apparently is also a Pentecostal preacher). Advocates of theistic evolution accept scientific evidence that the world is very old and has come into its present form through billions of years of gradual changes. (I’m not a religious person myself, but can see how theistic evolution would be an attractive and reasonable view for many people who are religious.)
As an example of where the practical and poetic sides of evolution meet, think of the southern shore of Lake Michigan, where the Indiana Toll Road passes through the huge industrial wastelands of Gary:the grim, depopulating city to the south, the smokestacks, blast furnaces, and slag heaps to the north, mile after mile of rustbelt ruins littering the shores of an inland sea. The steel industry made Gary a boomtown, and the industry’s decline has left it a husk. But some of the factories are still working, and they depend for their work on key three main ingredients: iron, coal, and limestone. Factories make steel by smelting iron in blast furnaces with coke (a purified form of coal) and limestone. The burning coke melts the iron and provides carbon, which combines with the iron to make steel. Limestone removes impurities from the iron, resulting in slag. Gary provides a convenient place for steel factories because it lies close to sources of coal (Illinois) and limestone (Indiana), and is connected by the Great Lakes to a major source of iron (Minnesota).
We owe coal, limestone and iron to three key evolutionary events: the invention of trees, shells, and plants.
The most recent of these is the invention of trees, which resulted in the formation of coal. The coal in Illinois formed during the Pennsylvanian period, just over 300 million years ago, when what is now Illinois was covered by vast, low-lying tropical rainforests. We know from fossils preserved in coalmines that these forests looked unlike any living forests. They had giant club mosses and tree ferns and all sorts of huge versions of plants that survive today only as small forms living in the shadows of more modern trees. These plants were able to grow so tall thanks to a newly evolved fiber, lignin, which they used to make strong, woody stems. In addition to helping the trees grow tall, lignin toughened their bark and protected them from insects, which could not digest the tough fiber. Neither could any of the bacteria or fungi that existed then. As a result, when these trees died, instead of rotting, they piled up and gradually turned into coal. As a result of all this accumulating carbon, the atmosphere developed a growing surplus of oxygen – which may explain the evolution of giant insects and other arthropods, including dragonflies with wingspans two feet wide and millipedes six feet long. Our very distant ancestors, early amphibians, crept and swam about in these swampy forests.
The invention of shells occurred much earlier, shortly before the Cambrian period, which started around 543 million years ago. We don’t know much about life before the invention of shells, because animals without hard parts don’t fossilize very well. But once shells were invented, we get lots and lots of fossils – including huge beds of limestone, made almost entirely from the shells of tiny animals, especially foraminifera: single-celled amoebas that live in tiny shells called tests. Indiana limestone was laid down in the Mississippian period, around 335 million years ago. At the time, a vast shallow sea covered much of Indiana. As tiny marine organisms died, they rained down to the bottom of the sea, their shells contributing bit by bit to what would eventually become limestone.
The invention of plants – or more precisely, photosynthesis – occurred even earlier, and had a profound effect on life on earth. The first creatures to capture sunlight to make food were bacteria. Eventually some of these, such as blue-green algae, developed a method of photosynthesis that produced oxygen as a waste product. At the time, oxygen was poisonous to most living things. As the oxygen waste built up in the atmosphere, some species evolved ways to deal with the poison, but most went extinct, or survived as refugees in crannies hidden from the deadly air. As oxygen dissolved in the sea, it combined with iron compounds already dissolved in the water to make iron oxide (rust), which sank to the bottom and accumulated in layers on the sea floor. The resulting banded iron formations of the Minnesota Iron Ranges are thus the result of biological activity some 2,000 million years ago.
Evolution is not just some story. It’s the explanation for how we get iron, limestone and coal. Without an understanding of evolution, we wouldn’t know where to look for these minerals – or other fossil formations, like oil. Knowing about evolution helps us understand that our supply of these fossil resources, however large, is ultimately limited. And without the glacial lakes formed at the end of the last Ice Age some 10,000 years ago, we would have a much harder time getting the iron from Duluth to Gary.