Why is evolution important and why should it be taught in school?
By Brian Thomas
In discussing the nature of science in my classes, what science is about, what science is not and pseudoscience, the topic of evolution often comes up. The following is my response to a student's question about why evolution is important and why it should be taught.
Find more here:
Understanding Evolution
National Center for Science Education
I think there are two main aspects here; the first is more general, and the second more practical.
1. Science is about understanding as much as we can about how the natural world works. The history of life is part of this, and that's what the biological theory of evolution talks about. The basic concepts were developed by Darwin and the theory has been developed, modified and improved since then by countless scientists using the process of science - come up with a hypothesis and then test that using experiments and observations.
Learning about what science has discovered about the universe is important in understanding how we fit in the world and also about how science works in general. Understanding how science works is critical to our modern society.
2. Evolution is practical -- the concepts that form the foundation of evolutionary theory today (genetic modification and natural selection) form the foundation for much of modern medicine. A good example is the fact that bacteria evolve resistance to the antibiotics we use - you may have heard of antibiotic resistant tuberculosis. If we did not recognize this evolution and how it works we would not be able to change tactics in how we treat these diseases. HIV is another example - this virus is constantly evolving and so treatments must take that into account to remain effective.
In a broader, but still practical sense, evolution forms the central organizing principle of all of biology. Any studies rooted in biology eventually refer back to this principle, even if remotely. It helps us understand life as it is today, as it was in the past, and how it may be in the future. It is predictive, testable (and falsifiable) and is in fact very well tested.
In a more philosophical vein, I see evolution as showing us our connectedness and interrelatedness to the world of life around us. This has practical consequences as well -- people who are more aware of the fact that all life is related are more likely to be concerned about protecting the environment and other species. Protecting the environment is important for our own well being, and preserving species is important in preserving the diversity that helps life thrive, including our own species.
You may at some point hear me say that people who say there is no evidence for evolution are lying, or have been lied to. The fact is, there is ample evidence for the scientific theory we call evolution, which says that life has changed in form and diversity over time through the processes of genetic variation and natural selection.
So, when someone says there is no evidence they are simply wrong. Either they know better and are truly lying, or they have heard this from someone else and they just accepted it as true. Somewhere down the line, someone has lied and it got passed on.
Many people feel that they must deny the reality of evolution because they think it invalidates all of their beliefs. I can understand this - it's scary to have your foundational beliefs undermined; I've been there and I know. They may have come to this conclusion based on how they read the Bible, or they may have simply been told that this is the case. This is terribly unfortunate and unnecessary, and is partly why I do get emotional about the issue - I hate to see people struggle with this unnecessarily, and I am deeply concerned about truth and honesty, which are central values of the scientific enterprise. I personally know many scientists who are devout Christians, who believe the core messages of the Bible regarding God, Jesus, salvation, etc., and who also accept the evidence for evolution without reservation. I would be happy to introduce you to some of these scientists if you are interested, or you can find links to some of their writing on the subject in the links posted here, of if you want more, check out these excellent books:
It seems that really one of the core issues when this topic comes up is why learn science at all? Or, why do kids need to learn science, why should it be taught in school? Any area of science has potential to step on toes - there are people who still think the Earth is flat. If we only taught completely benign science, we'd never teach science at all. Likewise, if we only taught absolutely "proven" ideas then there would be no science classes. Every single theory we have in science has some level of uncertainty. Some are so well established no one questions them, some less so. Just because it has not been "proven" absolutely does not mean it should not be taught - it's the best understanding we have so far, and the continual process of improving that understanding is what science is all about.
So why should we bother, why go through it, why teach kids science at all?
It's essential. Science is a way of thinking, a way of figuring things out about the natural world and it works incredibly well. All of our comforts today, all of our economic development rests on a scientific way of approaching the natural world. Everyone needs to know how to think in a scientific way, even if you never "do" science. We need to learn to think this way because we have so many problems that demand our decisions, and if we cannot think about them in a scientific way then we are very likely to make bad decisions. This is not to say we only think about them scientifically (nuclear power is a good example), but science must be part of the conversation, and if our citizens do not know how to think scientifically, at least a little bit, then bad decisions are much more likely to result.
One thing that is often mentioned when discussing evolution is "purpose," or the lack thereof in the scientific theory. Purpose is not something science can tell us about. It can tell us how, but not why. So putting your own ideas about purpose in is perfectly fine, it's just not science and should not be in a science class. This doesn't mean the world is purpose-less! It just means science is not the way to understand that purpose, if there is one. I have no problem with people teaching their children about their own views of the world, but if those children are to have an accurate view of the natural world around them, as well as an accurate view of how science works, then they need to learn the best available science.
Now for some details about some of the misunderstandings that people often have about the scientific theory of evolution. If you want more on this, I'd encourage you to go through the content here:
http://evolution.berkeley.edu/evolibrary/home.php
and especially this part:
http://evolution.berkeley.edu/evosite/misconceps/index.shtml
1. Let's first separate out "evolution" from ideas about the origin of life. Evolution itself is a theory about how life has changed over time. By itself, it does not say anything about how life first formed, and its validity does not in any way rest on how life formed. The formation of life is at present an unsolved problem, and a very difficult one. There are many ideas, some better than others, but no solid theory.
So, evolution is not about the origin of life, and right now we do not have a satisfactory scientific theory of the origin of life. Maybe we will someday, and maybe God did it and we won't ever have a scientific explanation.
2. Evolution does not come "out of nowhere" or even really "by random chance." These are very common misconceptions.
First, the process of evolution works on existing life. Again, it doesn't start out with nothing (the origin of life problem), it starts with already living beings, and these change over time.
Now, how does change occur? Not by random chance - by natural selection. There is one element of "chance" in this - genetic modification happens by chance occurrences like radiation changing a DNA molecule. Any change which occurs this way will then be acted on by natural selection - if the change makes the being more able to survive then the new change will be passed on. This process is directly and experimentally verified. It has been observed over and over again in the lab.
Now, about how we know this process has changed life over the long-haul, before we were there to test it in the lab. We know because we see a progression of fossils. It may be you've been told that there are no "transitional fossils" which show the incremental changes from one species to another. That is one of those lies that are floating around. It simply is not true. I would be happy to help you find examples of this evidence if you like.
3. People often state that something "became" something else, like "monkeys became cavemen." This again is a misunderstanding of how the process works. Let's take an example, using the descent of say, rats and mice. These two species are obviously related, but not the same.
At some point in the past, neither rats nor mice existed, but a small rodent with similar features did. This is what we call the "common ancestor." Let's say there is a large group of rodents and because the food where they live is running out they split up into two groups and move to separate areas. Now, in each group, some of the individual rodents experience genetic modifications and by the (not random) process of natural selection some survived to have young and some did not. This happens in both groups, but it may happen in different ways. Let's say group 1 ends up living in a place where the nuts are very tough and larger, sharper teeth make it easier to eat and survive. In this group, modifications which happen to lead to larger, sharper teeth will get passed on until several generations later we have a group of rodents with bigger sharper teeth than their ancestors which moved to the region in the past. Now, let's say that group 2 lives where the seeds are smaller. In that case, modifications which lead to smaller teeth might be more suitable to survival. And so, by the same process, under different conditions, we now have a group of rodents who have smaller teeth than their ancestors who moved there in the past.
This is a simple, and limited example. And you may say that it doesn't explain how very different species evolved, and you'd be right that this example does not do that. But, we can extend this, and make predictions about what should be seen in the fossil record and the genetic record, and what we find lines up remarkably well with what's predicted.
© 2008 Brian Thomas
"The views and opinions expressed in this page are strictly those of the author. The contents of this page have not been reviewed or approved by Washburn University."
This page was last updated on 8/23/08 by Brian Thomas brian.thomas@washburn.edu