Aug 4th 2017

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

by Paul Braterman

Hon. Research Fellow; Professor Emeritus, 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

Aug 8th 2019
Consider the following facts as you wend your way to the Guggenheim Museum and its uppermost gallery, where you will presently find The Death of Michael Stewart (1983), Basquiat’s gut-punching tribute to a slain artist, and the centerpiece for an exhibition that could hardly be more timely.
Jul 22nd 2019
It’s worth remembering, then, that we are not designed to be consistently happy. Instead, we are designed to survive and reproduce. These are difficult tasks, so we are meant to struggle and strive, seek gratification and safety, fight off threats and avoid pain. The model of competing emotions offered by coexisting pleasure and pain fits our reality much better than the unachievable bliss that the happiness industry is trying to sell us. In fact, pretending that any degree of pain is abnormal or pathological will only foster feelings of inadequacy and frustration. Postulating that there is no such thing as happiness may appear to be a purely negative message, but the silver lining, the consolation, is the knowledge that dissatisfaction is not a personal failure. If you are unhappy at times, this is not a shortcoming that demands urgent repair, as the happiness gurus would have it. Far from it. This fluctuation is, in fact, what makes you human.
Jul 10th 2019

 

The eight-mile ‘river of flowers’ that grows alongside a motorway nea
Jul 5th 2019
"........since World War II, 97% of unimproved grassland habitats have vanished from the UK. This has contributed to the loss of pollinating insects – and the distribution of one third of species has shrunk since 1980."
Jun 25th 2019
"For many of us, eating a meal containing meat is a normal part of daily life. But if we dig deeper, some sobering issues emerge. Every year, 66 billion terrestrial animals are slaughtered for food. Predictions are that meat consumption will rise, with increasing demand for meat from China and other Asian countries as their standards of living increase. The impact of grazing animals on the environment is devastating. They produce 18% of the world’s greenhouse gases, and livestock farming is a major contributor to species extinctions."
Jun 22nd 2019
"Throughout history, people who have gained positions of power tend to be precisely the kind of people who should not be entrusted with it. A desire for power often correlates with negative personality traits: selfishness, greed and a lack of empathy. And the people who have the strongest desire for power tend to be the most ruthless and lacking in compassion."
Jun 21st 2019
"In this era of Trump, it should perhaps come as no surprise to find supposed experts lacking in historical perspective. Yet it is still disappointing to find this deficit in the New York Times, which prides itself on clinging to a pursuit of the truth. So it is a bit sad to read the plaintive cry of Allison Schrager’s op-ed of May 17, lamenting that the domination of art markets by the super-rich will somehow force smaller galleries to go out of business, and imperil the careers of young artists."
Jun 17th 2019
Extract: "ust as an earlier generation resisted the limiting post-War era "white middle class" definition of being American by giving birth to an awakening of cultural pluralism and ethnic pride, it falls to our generation to fight for an expanded view of the idea of being American that rejects the narrow view projected by Trump and white nationalists. The idea of America isn't theirs. It's bigger than they are and unless our national cohesion is to unravel, this challenge must be met by projecting an inclusive vision of America that celebrates our inclusive national identity in an increasingly globalized world."
May 28th 2019
Whatever other attributes Homo sapiens may have – and much is made of our opposable thumbs, upright walking and big brains – our capacity to impact the environment far and wide is perhaps unprecedented in all of life’s history. If nothing else, we humans can make an almighty mess.
Apr 29th 2019
A century ago, unspeakable horrors took place on every continent that were known only to the victims and the perpetrators. Not so today. As a result of advances in communications – from the telegraph and radio to satellite television and the internet – the pain and loss of global tragedies are brought home to us in real time.   Because of this expanding consciousness, the post-World War II era has witnessed the rise of visionary leaders and the birth of countless organizations dedicated to alleviating suffering and elevating the causes of peace, human rights, and tolerance among peoples. Individually and collectively, they have championed the rights of peoples in far-flung corners of the world, some of which had been previously unknown to those who became their advocates. These same leaders and groups have also fought for civil rights and for economic, social, political, and environmental justice in their own countries. 
Apr 23rd 2019

 

“Cursed be that mortal inter-indebtedness which will not do away with ledgers. I would be free as air; and I’m down in the whole world’s books. I am so rich… and yet I owe for the flesh in the tongue I brag with” (Moby Dick, chapter cviii). 

Apr 20th 2019
Economists speak in numbers only, clinging to statistical data and quantitative models. We do so in the hope of looking objective. But this is counter-productive – “data” cannot tell us everything. Other social sciences such as sociology and anthropology use a broader range of methods, and consequently have a broader perspective on society. If we take our societal role of adviser on economic matters seriously, we will need to open up and adopt the insights that these other disciplines bring us about how the economy works.Politics and economics are inextricably intertwined, as Adam Smith, David Ricardo, Karl Marx knew all too well. Somehow this has been forgotten. This does not mean economists need to get political or choose sides. But it does mean that we ignore politics at our own peril – by blindsiding ourselves or dismissing it as “external stuff”, we hamper our understanding of the very system we study.
Apr 16th 2019
Although it is not likely that many visitors who pass by the Giacometti sculptures on their way to Las Meninas will ponder it, the contrast between these works underscores the single greatest transformation in the history of western art, from a regime in which artists tailored their works to the aims of individual patrons, to one in which artists choose their techniques and motifs according to their own concerns, and only then present the products to an anonymous competitive market
Apr 4th 2019
On March eleventh, the world lost someone who was very special, who made a mark and touched people with his voice, as a singer, a humorist and writer..........I had the great good fortune to know him and spend time with him, playing music, talking with him – he was a man of immense culture, fluent in Hebrew, German, English, and Romanian. He loved New York City and Vienna and we would often swap apartments so that he could stay in New York while I lived at his place in Vienna.
Apr 1st 2019
The ongoing controversy over admissions to American universities has overlooked the one of the most telling aspects of the scandal—that it took place with the connivance and active participation of administrative bureaucracies able to act with impunity in the pursuit of their interests. Neither the professoriate, often the target of opprobrium from the left and the right, nor the student body, also the target of criticism from both sides of the political spectrum, bore any of the responsibility.  Current debates over “what ails” U.S. colleges and universities consistently ignore the single most important dynamic of all institutions—their structure of power. I suggest that the way in which power is allocated within American universities is strikingly similar to that of Soviet-type regimes. Presidents, chancellors, provosts, deans, and their bureaucratic apparatuses preside over vast real-estate and financial holdings, engage in the economic equivalent of central planning, have inordinate influence over personnel, and are structured hierarchically, thereby forming an enormously powerful “new class” like that described by the renowned Yugoslav dissident, Milovan Djilas, in the mid-1950s. 
Mar 22nd 2019
When you think of religion, you probably think of a god who rewards the good and punishes the wicked. But the idea of morally concerned gods is by no means universal. Social scientists have long known that small-scale traditional societies – the kind missionaries used to dismiss as “pagan” – envisaged a spirit world that cared little about the morality of human behaviour. Their concern was less about whether humans behaved nicely towards one another and more about whether they carried out their obligations to the spirits and displayed suitable deference to them. Nevertheless, the world religions we know today, and their myriad variants, either demand belief in all-seeing punitive deities or at least postulate some kind of broader mechanism – such as karma – for rewarding the virtuous and punishing the wicked. In recent years, researchers have debated how and why these moralising religions came into being.
Mar 19th 2019
European food and ingredients have become staple food choices for the British. The use of ingredients such as garlic, peppers, avocados, Parmesan cheese and all those other European ingredients that are now taken for granted are relatively new and were still rare in the 1990s. When I was growing up in rural Devon in the 1970s, olive oil was only really readily available in chemists as a cure for earache – now it is found in most food cupboards. And wine drinking has permeated through all social classes.
Mar 12th 2019
The Guggenheim’s strange and wonderful exhibition of Hilma af Klint’s groundbreaking, yet largely unknown body of abstract art is an important event – one that challenges us to not only rethink the early history of twentieth century abstract art, but to recognize her vision of art and reality as unique, authentic, and deliciously puzzling. 
Feb 25th 2019
Looking at the world today, it's clear that the consequences of this imperial legacy are still with us. If anything has changed it is that we are now beyond just viewing the former "natives" as far-away oddities. They are now living within our borders, having come to find the opportunities they were denied at home. So when I hear the reactions in the West to the influx of South Asians going to the UK, or North Africans going to France, or Central Americans migrating to the US, I can only say "Guys, these are the fruits of your conquest – your chickens coming home to roost."
Feb 25th 2019
Extracts: "The new novel Sérotonine by Michel Houellebecq, the bad boy of French literature, is a saga of depression and death told with such irony and wit that readers seem to love it despite the unsettling themes. Maybe it’s just me but I found myself laughing out loud.......True to form, the French don’t agree on Houellebecq – or anything else, for that matter. The impact of his new novel has divided the readers into opposite love-hate camps with hardly any middle ground. Houellebecq cannot leave you indifferent, notes a literary friend of mine"........Picture: Michel Houellebecq, by the reviewer Michael Johnson.