One aspect of meandering rivers that has always interested me is oxbow lakes. Oxbow lakes are parts of a meandering river that have been cut off from the main river and become U-shaped lakes with no inflow or outflow of water. They derive their name from the collar placed on the neck of oxes to which the plow is attached. Oxbow lakes are formed because in the bend of a curving river there is more erosion of the outer bank and more sediment deposition on the inner bank. Thus the shores at the narrow side of a river loop tend to erode and connect establishing a new channel for the river, sealing the loop, and turning it into a lake. Oxbow lake formation is a well-recognized consequence of the physics of meandering rivers and there are even mathematical models that explain their formation.
Even before science came of age, people living in river basins figured out that oxbow lakes formed as part of normal river dynamics. Although oxbow lake formation cannot be seen in real time because they can take decades to form, any meandering river has a number of these potential lakes in various stages of formation. All that smart people had to do was put together all these different stages in a sequence to figure out how oxbow lakes are formed. Today with the advent of satellites we can see the formation of oxbow lakes such as the one shown in the video below in the Ucayali River in Peru between 1985 and 2013.
As far as I know, the notion of linking together the different stages of oxbow lake formation to answer the question of how these landlocked lakes form never generated any controversy. You would probably agree with me that linking all these stages to form a sequence was the smart and logical thing to do. Now I want to connect the narrative of this post so far with its title and address in parallel the theory of evolution.
Even before modern science came along, fossils of plants and animals (different stages of oxbow lake formation) were being discovered all over the world that bore resemblance to modern plants and animals (fully formed oxbow lakes), but at the same time displayed some differences. Charles Darwin had the idea that (just as different stages of oxbow lake formation are linked) all these fossils were linked and represented ancestral forms of these modern plants and animals (stages of oxbow lake formation). Although Darwin’s idea at the time he formulated it came short of fully explaining how this could happen, modern genetics coupled to other disciplines like geology, embryology, chemistry, physics, ecology, and so forth have confirmed that Darwin’s idea is true.
I realize that there are differences between fossils and stages of oxbow lake formation. For example, fossils are static and represent the past, while the different stages of oxbow lake formation are dynamic and are all found in the present. Also, some of the biggest evolutionary changes take place over millions of years, so we will never be able to see this process in those time scales as we can see oxbow lake formation with satellites. But my main point is that if we want to know the origin of an entity, whether an oxbow lake or an organism, and we find several apparent stages in the development of that entity that seem to point to a sequence, then linking these stages to infer how the entity came into being is a perfectly logical and smart thing to do.
So why do so many Americans accept the theory of oxbow lake formation without any controversy but reject the theory of evolution? If it is legitimate to put together all the stages of oxbow lake formation to come up with an explanation regarding how these lakes arise, why is it not acceptable to do the same with fossils and living things including humans?
This is, of course, a rhetorical question. I know that creationism is based on a literal interpretation the Bible. Whereas scientists look at different stages of oxbow lake formation or fossils and then follow a bottom-up approach allowing observations and experiments to guide them in finding the truth, creationists take for certain whatever is in the Bible and follow a top down approach trying to fit observations or experimental results to scripture. I suspect that if the Bible contained a very specific religious description regarding the creation of oxbow lakes that had nothing to do with river dynamics, creationists would also be objecting current scientific explanations of oxbow lake formation.
I don’t mean to disrespect or belittle something as important as faith and religion. I subscribe to Stephen Jay Gould’s proposal that science and religion occupy what he called non-overlapping magisteria, and I am sympathetic to the plight of a creationist who with horror sees atheism as the only alternative to not believing literally in the creation story described in the book of Genesis. As I have explained before, I believe that science should not operate in a vacuum. We should provide believers with a way to reconcile their beliefs with the fact of evolution.
One possible way to do this involves the finding by the Pew Research Center that support for evolution as gauged by a poll can change considerably if the phrasing of the question is altered. If people were asked whether humans evolved over time by natural selection with God having nothing to do with this or whether humans have existed in their present form since the beginning of time, 31% chose the latter alternative, which is the strict creationist interpretation. However, if the option was included to allow for God somehow guiding the evolutionary process giving rise to humans, support for the strict creationist view dropped to 18%.
Of course, it is not in the nature of science to deal with God or the possibility that God influenced evolution, but I favor approaches such as allowing for a role for God in the process of evolution as a means of making our population more accepting of basic scientific facts in order to avoid the needless wasteful social conflict that has dragged on for decades. That way we can speed up the day in which we will all accept that the natural history of oxbow lakes and living organisms have some things in common.
Image from the air of The Carstairs Meanders in the UK by Thomas Nugent is used here under an Attribution-ShareAlike 2.0 Generic (CC BY-SA 2.0) license. The diagram of Ox Bow lake formation by Maksim is used here under an Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) license. The image of the evolution of the horse by Mcy jerry is used here under an Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) license.