Once upon a time ago, before I got into the sciences, I had a young earth creationist coworker. She claimed that since the sun went through periods of growing and shrinking, carbon dating was inaccurate, and therefore the Earth had to be 6,000 years old. This was the first time I’d ever come across a creationist in the flesh, with my previous experiences being church lady-type letters to the editor and occasional local-yokel street interviews on the 6 O’Clock News. Put off-guard, I quickly realized I was out of my element with offering a counterpoint, and didn’t feel like getting into a debate while cleaning a public bathroom. Also, she was much bigger than me. You have to pick your battles.
My point is not to call this girl stupid or foolish, as I knew she was neither. I know she had been homeschooled for a large portion of her life, and I now assumed it was heavily religious-based. She’d probably never received a clear explanation about evolution and the processes that have formed the Earth throughout time.
Carl Sagan best expressed the danger of having a good amount of the populace believe in religious dogma over scientific principles in a developed society:
“We live in a society exquisitely dependent on science and technology, in which hardly anyone knows about science and technology.”1
I believe when we talk to skeptics, we should change the way we talk about evolution. Right now, the misconception is that evolution theorizes that we descended from monkeys. To this, my knee-jerk reaction is to correct them by saying that humans and primates descended from a common ancestor, as if this really makes a difference to some folks (it doesn’t). I think when we talk about evolution, we need to focus on microevolution and let the caveman and dinosaur thing alone for the time being. Baby steps, you know?
The basis of evolution through the process of natural selection (microevolution) is defined as the differential survival and reproduction of individuals due to differences in their physical traits (phenotype). Basically speaking, critters that possess specific traits can survive better than others and have a higher change of reproducing in their environmental conditions. This is a very simple, logical explanation and you would be hard-pressed to find anyone other than the deliberately obtuse that disagrees with it.
Natural selection can be broken down to four basic tenets:
1) Individuals within a set population have varied traits: We are different heights, have different sizes of feet, require different amounts of sleep, etc.
2) This variation is heritable: You probably look like your parents. Sorry.
3) Organisms differ in their ability to survive and reproduce: Good strategies from a fitness standpoint: Some of us have tons of children and leave them to their own devices, like oak trees, sea urchins, and your hateful neighbors, while some of us have few children, but invest lots of time and effort in raising them, like elephants.
4) This survival and reproduction are non-random: This tenet invokes environmental conditions and resource availability, as well as interactions with other species.
If we want to bring genetics into this (and we absolutely do; who still doesn’t believe in modern genetic theory?) we can say this:
1) Genes mutate. It happens.
2) Sometimes this mutation changes the structure of the proteins it codes for.
3) Sometimes this altered protein gives us the ability to tolerate an environmental pressure.
4) Tolerating an environmental pressure allows us to produce offspring with the same mutation while others die off; the end result is that the frequency of this mutation is increased in the total gene pool.
If we want to get back to the dinosaurs, we can say the cumulative effect of billions of years of changing environments have allowed for some pretty amazing creatures to come and go. But, let’s resist the urge to talk about that, and stay focused on the small-scale stuff. Because if there is any concept necessary for our modern, developed society to believe in and understand, it’s microevolution.
Through microevolutionary principles, we would not have developed two of the most important contributions to society, antibiotics and pesticides. Without antibiotics, we would be subject to horrible infections, and without pesticides, we would be subject to devastating crop failures. Many of us would be dead or suffering.
Antibiotics and pesticides are essentially similar. In a nutshell, they discourage growth of a pest by directly or indirectly killing or impeding its ability to reproduce. The key is to target a biological process necessary for the survival of the pest, but absent or not crucial in other critters. Evolution plays a rather abstract, but important role in the discovery and formulation of antibiotics and pesticides. The further away we are on the evolutionary scale from a particular pest, the more biologically and mechanistically different we are in terms of respiration, consumption/metabolism, and reproduction.
Critters far away from us on the tree of life, like bacteria, generally have tons of unique mechanisms we can screw with, without affecting our own biological processes. For example, β-lactams, a common class of antibiotics, acts by inhibiting normal cell wall formation on bacteria. Naturally, animals do not have a cell wall, so we are unaffected by the drug, save some minor side effects. To develop new types of antibiotics, we research the various mechanisms that bacteria uniquely use to grow, acquire nutrients, and reproduce. We then look towards methods to disrupt these mechanisms at one or more points, with the end result being that the bacteria die off.
Pesticides work similarly; they target necessary biological functions needed for the pest to survive and/or thrive. They also could be a great variety of things, from bacteria to fungi to insects to plants. The same principles apply; we identify biologically crucial pathways or mechanisms in our pests that have a negligible effect on us.
In finding ways to control insects, we need something effective, but not insanely toxic to humans, birds, and the surrounding environment. Being closer on the tree of life, there are a lot of biological similarities between humans and insects, and there are many cases in which the desire for effectiveness overrules the need for safety. An example of this is seen in the organophosphate class of insecticides. While very effective at controlling insect pests, they are extremely dangerous to humans, other mammals, and our bumblebee friends. Organophosphates irreversibly inhibit acetylcholinesterase, which is crucial for nerve function in all of the above critters. Incidentally, it is a fantastic nerve agent, and has had some pretty devastating consequences.2 Because of this, organophosphates are heavily regulated and illegal to use on your home garden.
Evolution has an important role in antibiotic and pesticide resistance. Because genetic mutations happen, and bacteria reproduce fast and often have the ability to quickly transfer genes to one another, we are likely going to end up with some mutations. An antibiotic or pesticide is basically a form of intense environmental pressure, which kills off much of the population. If a mutation occurs that allows the bacteria to bypass the targeted pathway, these new drug-resistant bacteria will reproduce uncontrollably. An example of this is the appearance of bacteria that produce β-lactamases, which cleave and destroy β-lactam, rendering the drug useless. Similarly with pesticides, the repeated use of the same formulas results in the appearance of pests completely immune and free to proliferate on our food crops3.
Antibiotic and pesticide resistance is a very hot topic for scientific research. Misuse of antibiotics has resulted in the appearance of frightening multi-drug resistant strains, making it absolutely necessary to stay invested in research programs. As for pesticides, beyond resistance, there is a long timeline of the accidents, misuses, and damaging effects to the environment and us. We need support for research into strategies that look for methods of pest control beyond the heavy use of chemicals, so that we move closer to productive yet environmentally friendly and sustainable agricultural practices.
This is where the necessity of a scientifically educated society comes in. If we force the type of education on children that distorts or outright denies scientific research to fit religious doctrine, we are not properly equipping them with the knowledge to contribute to an increasingly technology driven world.
Again, Carl Sagan said it best:
“We’ve arranged a society based on science and technology, in which nobody understands anything about science and technology. And this combustible mixture of ignorance and power, sooner or later, is going to blow up in our faces. Who is running the science and technology in a democracy if the people don’t know anything about it?” 4
If you are reading this article, you probably live in a country that has religious freedom, which is great. But, we have to look at the caveat “as long as you aren’t hurting anybody.”
Those who deny the existence of evolution, along with other issues that have huge empirical backing like climate change, are indeed hurting lots of someones. It’s mildly annoying to witness folks that deny the existence of evolution, but still enjoy the benefits of modern medicine and developed agricultural systems. But, these people vote, run for office, assume leadership and decision-making positions, sit on school boards,5 lead science and technology committees,6 slash funding for research, slash funding for education, and pump money into bizarre creationist museums.7
The end result of this is that we as a society are basically screwed.
So, when coming across creationists that want to have The Talk, be nice, discuss natural selection, and don’t mention anything about primate ancestors. We need everyone on board.
1 Sagan, C. 1990. Why we need to understand science. Skeptical Inquirer, Vol 14-3
2 S. K. Rastogi, S. Tripathi, and D. Ravishanker 2010. A study of neurologic symptoms on exposure to organophosphate pesticides in the children of agricultural workers. Indian J Occup Environ Med Aug; 14(2): 54–57
3 Gut, L., Schilder, A., Isaacs, R., McManus, P. How pesticide resistance develops: http://grapes.msu.edu/pesticideResist.htm. Excerpt from: Fruit Crop Ecology and Management, Chapter 2: “Managing the Community of Pests and Beneficials.” Feb. 17, 2016. Found here.
4 From an interview with Charlie Rose, May 27th, 1996
5 Kitzmiller vs. Dover Area School Board, 2005.