Aug 4th 2017

How to slam dunk creationists when it comes to the theory of evolution

by Paul Braterman

 

Hon. Research Fellow; Professor Emeritus in Chemistry, University of Glasgow

The 2001 discovery of the seven million-year-old Sahelanthropus, the first known upright ape-like creatures, was yet more proof of humanity’s place among the great apes. And yet Mike Pence, then a representative and now US vice president, argues for the opposite conclusion.

For him, our ideas about our ancestors have changed, proving once more that evolution was a theory, and therefore we should be free to teach other theories alongside evolution in our classrooms.

A skull cast of Sahelanthropus, the first upright ape-like creatures which lived seven million years ago. Didier Descouens, CC BY-SA

How to respond? The usual answer is that we should teach students the meaning of the word “theory” as used in science – that is, a hypothesis (or idea) that has stood up to repeated testing. Pence’s argument will then be exposed to be what philosophers call an equivocation – an argument that only seems to make sense because the same word is being used in two different senses.

Just words

Evolution, Pence argues, is a theory, theories are uncertain, therefore evolution is uncertain. But evolution is a theory only in the scientific sense of the word. And in the words of the National Academy of Sciences, “The formal scientific definition of theory is quite different from the everyday meaning of the word. It refers to a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence.” Attaching this label to evolution is an indicator of strength, not weakness.

If you take this approach, you have failed to understand the purpose of Pence’s rhetoric, or why it is so appealing to creationists. Pence is an accomplished politician, and knows exactly how to appeal to his intended audience. He is also an accomplished trial lawyer, which makes him a conjuror with words, and like any skilful conjuror he has pulled off his trick by distraction. Pence has drawn us into a discussion about words, when our focus should be on the evidence.

I would suggest the opposite approach. The problem is not really with the word “theory” at all. Students will have learned its meaning in the same way they learn meanings in general: by seeing how the word is used.

They will have heard of atomic theory, which no one has seriously doubted for over a century. And what about the theory of gravity? Finally, they may have seen how Darwin himself uses the expression “my theory”, although at the time it was neither comprehensive nor well supported (there were huge gaps in the fossil record), to refer in a very general way to his linked ideas about mutability of species, common descent, and the power of natural selection.

So if anyone says, “Evolution is a theory”, don’t give them a lecture on the meaning of the word “theory”. If you do, you’ve fallen into the trap of making it seem that how we define words should affect how we see reality. You will be fighting on ground of your opponent’s choosing, since arguing about how to apply words is the stock in trade of theologians, preachers and lawyers like Mike Pence.

The correct response is to say that evolution is a theory – like gravity is a theory – and then redirect attention to the evidence. And that evidence is overwhelming.

Evolutionary ammo

Start with family relationships. Carl Linnaeus showed how living things can be classified into species, genera, families and so on, and Darwin pointed out that this is exactly the structure we would expect from a family tree. All dogs are canines, so dogs share an ancestor with foxes; all canines are carnivora, so dogs share a more remote ancestor with bears; all carnivora are mammals, so dogs and sheep are, albeit more remotely, related, and so on.

Then look at the discovery over the past few decades of family relationships at the molecular level, and the fact that the molecular family tree matches that based on anatomical resemblances.

Observe the fossil record. Once lamentably full of gaps (Darwin was among the lamenters), it is now densely populated. A century ago, it still made sense to point to the “missing link” between humans and pre-human apes. Now we know of several different hominin species living alongside each other, and the problem becomes one of distinguishing our grandparents from our great uncles. And yes, there are missing links in the chain, but without evolution we would not have a chain at all.

And then there’s biogeography: for example, why marsupials are only found in South America and Australasia, and except for a few species that made their way across the Isthmus of Panama, are never found elsewhere.

Plus we can actually observe evolution, and study it in the field or in the lab. The emergence of pesticide resistance is evolution in action, as shown in the justly famous Harvard/Technion demonstration “evolution on a plate”. So is the delightful Russian experiment of breeding tame foxes. Artificial selection, just as much as natural selection, is evolution in action.

And finally, and most convincingly, we must look at the way that these different lines of evidence mesh together. We can apply biogeography to the fossil record, and link it to what we know about the movements of the continents. Using the methods of molecular biology, we can identify and time the mutations that led different species to diverge from their common ancestor, and match the timing against the fossil record.

Thus the fossil record, deep anatomical resemblances, and DNA evidence agree in showing that whales, for instance, are closely related to hoofed mammals, diverging from them in the Eocene period. There are many other examples of such consistency.

Then, and only then, pause to explain how a scientific theory is an interlocking connection of ideas that explain things about the world, and that evolution is one of the most successful examples. And challenge the Mike Pences of this world to spell out exactly what they would like to see taught alongside the Theory of Evolution – and why.


This article was originally published on The Conversation. Read the original article.




To subscribe to Facts and Arts' weekly newsletter, please click here.

To follow Facts & Arts' Editor, Olli Raade, on Twitter, please click here.

If you have something to say that you want to say on Facts & Arts, please

Write to the Editor, or write a comment in the comments section.

Browse articles by author

More Essays

Jul 16th 2024
EXTRACTS: "Trump joins tens of thousands of Americans treated for non-fatal gunshot wounds each year. Such experiences can shatter people’s assumptions that they are living in a safe, understandable and controllable world, leaving them feeling unworthy, unsafe and unsure. As a result, survivors of non-fatal gun violence face increased risks of depression, anxiety, substance use and post-traumatic stress disorder (PTSD). PTSD can feel overwhelming." ---- ".... some trauma survivors experience post-traumatic growth. They may develop greater empathy, stronger relationships, deeper spirituality and find new meaning in life. After being shot in 1981, the then president Ronald Reagan’s trauma seemed to deepen his sense of empathy and humility. He felt God had spared him for a reason, spurring him to reduce nuclear tensions with the Soviet Union."
Jul 15th 2024
EXTRACTS: "Artificial sweeteners such as sucralose are not metabolised by the human body so they are excreted – this is what makes them low-calorie sugar alternatives. And that’s where the environmental problem begins. Current wastewater treatment plants are unable to remove these sugar mimics, meaning they end up in our environment – in our water, rivers and soil." --- "Forever chemicals are increasingly present in our streams, rivers and oceans – most notably per- and polyfluoroalkyl substances (PFAS) that don’t degrade. PFAS are synthetic chemicals found in many consumer products, including skincare products, cosmetics and waterproof clothing. PFAS can remain in the human body for many years, and some present significant risks to our health – potentially causing liver damage, thyroid disease, obesity, infertility and cancer."
Jul 3rd 2024
EXTRACTS: "Psychologist, James Hillman had concerns about what I like to call the 'loneliness-as-pathology' "---- "....Hillman went on to argue...: 'If loneliness is an archetypal sense built into us all from the very beginning, then, to be alive is also to be lonely. Loneliness, therefore, will come and go as it chooses in the course of a lifetime, quite apart from our efforts to deny or avoid this reality.' "
Jul 3rd 2024
EXTRACT: "How can we be at least 15 times richer than our pre-industrial Agrarian Age predecessors, and yet so unhappy? One explanation is that we are not wired for it: nothing in our heritage or evolutionary past prepared us to deal with a society of more than 150 people. To operate our increasingly complex technologies and advance our prosperity, we somehow must coordinate among more than eight billion people."
Jun 25th 2024
EXTRACTS: "What’s interesting about the entire Russia-North Korea showy display of camaraderie is China’s response: silence. China has misgivings about how things are unfolding, which reports suggest prompted Chinese president Xi Jinping’s call to Putin to call off the latter’s visit to Pyongyang. Obviously, Putin didn’t heed Xi’s request." ----- "The Sino-Korean animosity dates back centuries and took shape when Korea was a vassal state of imperial China. Unfortunately, this animosity extended to modern times when Mao Zedong decided to station Chinese troops in North Korea even after the conclusion of the Korean war, and when Beijing did not aid Pyongyang in its nuclear ambitions. It didn’t help either that the founding leader of North Korea, Kim Il-sung, was suspected of espionage and was nearly executed by the Chinese Communist party in the 1930s."
Jun 19th 2024
EXTRACT: "Ultra-processed foods (such as packaged snacks, sugary drinks, instant noodles and ready-to-eat meals) often contain emulsifiers, microparticles (such as titanium dioxide), thickeners, stabilisers, flavours and colourants. While research on humans is limited, studies on mice have shown that these ingredients alter the gut microbiome (the community of microorganisms living in the intestines) in several ways. These many microbiome changes can in turn affect the way the immune system functions."
Jun 9th 2024
EXTRACT: "Alzheimer’s disease can be split in two subgroups, familial and sporadic. Only 5% of patients with Alzheimer’s are familial, inherited, and 95% of Alzheimer’s patients are sporadic, due to environmental, lifestyle and genetic risk factors. Consequently, the most effective tactic for tackling Alzheimer’s is preventative and living a healthy lifestyle. This has led researchers to study risk factors associated with Alzheimer’s."
Mar 8th 2024
EXTRACT: "This study suggests that around 10% of people diagnosed with dementia may instead have underlying silent liver disease with HE causing or contributing to the symptoms – an important diagnosis to make as HE is treatable."
Jan 28th 2024
EXTRACT: "Health disparity is a powerful weapon in the savage class warfare otherwise known as neoliberalism. (In 2020, the RAND Corporation did a study of the transfer of wealth over the last several decades from the working-class and the middle-class to the top one percent. Their estimate is a staggering $47 trillion – that is how much the “upward redistribution of income” cost American workers between 1975 and 2018.) Neoliberalism is a brutal form of labor suppression, which uses health as a means of maintaining and reproducing a condition in which wealth is constantly being redistributed upwards, and the middle-class is kept in a constant state of fear of sinking into the ranks of the poor. Medical expenses are the leading cause of bankruptcies in America – and that’s according to the American Bankruptcy Institute. The ballooning costs of healthcare serve to maintain a system marked by morally unacceptable health inequity and injustice."
Jan 28th 2024
EXTRACT. "But living longer has also come at a price. We’re now seeing higher rates of chronic and degenerative diseases – with heart disease consistently topping the list. So while we’re fascinated by what may help us live longer, maybe we should be more interested in being healthier for longer. Improving our “healthy life expectancy” remains a global challenge. Interestingly, certain locations around the world have been discovered where there are a high proportion of centenarians who display remarkable physical and mental health. The AKEA study of Sardinia, Italy, as example, identified a “blue zone” (named because it was marked with blue pen),....."
Jan 4th 2024
EXTRACT: ""Tresors en Noir et Blanc" presents 180 prints from the collection of the Musee des Beaux-Arts de la Ville de Paris, also known as the Petit Palais.  The basis of the museum's print collection is 20,000 engravings amassed by a 19th-century collector, Eugene Dutuit, " ----- "This wonderful exhibition, the tip of a great iceberg, serves to emphasize how unfortunate it is that the tens of thousands of prints owned by the Petit Palais are almost never seen by more than a handful of scholars who visit them by appointment.  Nor is the Petit Palais the only offender in this regard,....."
Jan 4th 2024
EXTRACTS: "And that is the clue to Manet’s work. He paints painting, regardless of his subject: he paints the medium itself, it as if he is constantly reminding us that this is a painting," ..........."This is a new conception of painterly truth at play here, a new fidelity to truth. Manet is the Kant of painting because he initiates a similar kind of “Copernican revolution” – we do not see the world as it is but as we are. " -------- " Among the most remarkable but unfamiliar of Manet’s work on display are those depicting the bloody aftermath of the Paris Commune of 1871.There is no question regarding Manet’s condemnation of the Versailles government’s actions following the defeat of the Commune, when some 25,000 Parisians were gunned down, including women and children."
Dec 27th 2023
EXTRACT: "Think of our brain like a map. When we’re young, we explore all corners of this map, sending out connections in every direction to make sense of our environment. Before long, we figure out basic truths – such as how to secure food, or where we live – and the neurological paths that make up these connections strengthen. Over time, a network emerges that reflects our unique experiences. Regions we re-visit often will develop established paths, whereas under-used connections will fade away. ---- Conditions such as addiction, chronic depression and post-traumatic stress disorder (PTSD) are characterised by processes such as repetitive negative thinking or rumination, where patients focus on negative thoughts in a counterproductive way. Unfortunately, these strengthen brain connections that perpetuate the unfavourable mental state."
Dec 14th 2023
EXTRACT: "While no one was looking, France has become a melting pot of European peoples. Its neighbors have traditionally been welcomed, and France progressively turned them into French boys and girls in the next generation."
Dec 4th 2023
EXTRACTS: "Being rich is essentially about having more stuff in general, including bigger houses." "..... if SUVs had not become widely adopted largely as a status symbol for the global middle classes, emissions from transport would have fallen by 30% over the past ten years. For the largest class of SUVs, six of the ten areas of the UK registering the most sales were affluent London boroughs like Kensington and Chelsea."
Nov 11th 2023
EXTRACT: "By using these “biomarkers”, researchers have discovered that when a person’s biological age surpasses their chronological age, it often signifies accelerated cell ageing and a higher susceptibility to age-related diseases." ----- "Imagine two 60-year-olds enrolled in our study. One had a biological age of 65, the other 60. The one with the more accelerated biological age had a 20% higher risk of dementia and a 40% higher risk of stroke."
Nov 6th 2023
EXTRACT: "We are working on a completely new approach to 'machine intelligence'. Instead of using ..... software, we have developed .... hardware that operates much more efficiently."
Nov 6th 2023
EXTRACTS: "When people think of foods related to type 2 diabetes, they often think of sugar (even though the evidence for that is still not clear). Now, a new study from the US points the finger at salt." ...... ".... this type of study, called an observational study, cannot prove that one thing causes another, only that one thing is related to another. (There could be other factors at play.) So it is not appropriate to say removing the saltshaker 'can help prevent'." ..... "Normal salt intake in countries like the UK is about 8g or two teaspoons a day. But about three-quarters of this comes from processed foods. Most of the rest is added during cooking with very little added at the table."
Oct 26th 2023

 

In 1904, Emile Bernard visited Paul Cezanne in Aix.  He wrote of a conversation at dinner:

Sep 11th 2023
EXTRACT: "Many people have dipped their toe into the lazy gardener’s life through “no mow May” – a national campaign to encourage people not to mow their lawns until the end of May. But you could opt to extend this practice until much later in the summer for even greater benefits. Allowing your grass to grow longer, and interspersing it with pollen-rich flowers, can benefit many insects – especially bees. Research finds that reducing mowing in urban and suburban environments has a positive effect on the amount and diversity of insects. Your untamed lawn won’t only benefit insects. It will also encourage more birds, such as goldfinches, to use your garden to feed on the seeds of common wildflower species such as dandelions."