In These Times, Season 3 | There’s Something About Darwin (Episode 3) 

Alex Schein: 

The vastness of scientific information can cause us to look up at the stars with awe but can also cause other reactions like skepticism and disbelief, denial and discomfort and even fear. On this season of the OMNIA Podcast, we talk to scientists and other scholars about scientific ideas that cause big reactions. We'll look at stories of science getting knocked around and standing back up again in a world full of polarization, politics, misrepresentation and simple misunderstanding. Welcome to In These Times: Fear and Loathing and Science. 

Speaker 2: 

In 1925, biology teacher, John Scopes, spiraled to fame in the legal battle that became known as the Monkey Trial. Whether a man was descended from the monkey or just making a monkey out of man was fought in a courtroom that challenged the truth of the Darwin theory of evolution. The existence of man in the prehistoric world was denied for according to the Bible, life began with Adam and Eve. 

Speaker 3: 

My child was very upset when they said that we were created from monkeys because he's very into his religion. 

Donovan Schaefer: 

There certainly is something that happens with the Darwinian change in the history of evolutionary biology that seems to be shuffling the decks. It's not an immediate thing. There are lots of religious people who seem to think that Darwinian biology, the Darwinian way of looking at the world is completely compatible with being religious in various different senses. And yet it's also undeniable that it's provoking a counterattack. 

Alex Schein: 

That was Donovan Schaefer from Religious Studies. You can hear more from him in episode one of this season. As he pointed out in our earlier conversation, the relationship between science and religious belief is complex but not always contentious. But when it comes to Darwin, there was always something different. 

If you were writing a book about the history of science denial, the chapter on Darwin would have to be one of the longest, but why? You can argue that we see evolution all the time. It is after all, why we're worrying today about the emergence of new variants of COVID-19. Does it boil down to a divide between religion and science that just can't be bridged? And what's at risk when what the science tells us about evolution is rejected? 

In this episode, we'll hear from a philosopher of science on what it is about Darwinian evolution that has made it a poster child for science denial and why it's important to teach the facts. Then we'll talk with an evolutionary biologist who explains how the process of continues around us in plain microscopic sight. Welcome to episode three, There's Something About Darwin. 

Michael Weisberg: 

There's two kinds of answers I think I can give you about why evolution is so kind of commonly misunderstood. The one part of it is it's actually a historical explanation. There was a conscious effort to make evolution an issue in culture wars. And this goes way back into the early 20th century. There was an explicit decision to choose a couple of wedge issues that the sort of political movements aligned to evangelical Christianity would use. Abortion is obviously one and evolution was another. And so that's part of the reason that this became so politicized. 

Alex Schein: 

That was Michael Weisberg. He's a philosopher of science who focuses broadly on the philosophy of biology. His work has branched into such areas as the public understanding of science, global climate policy and climate change impacts on human communities, along with projects in the Galapagos where he engages local populations in the process of environmental protection. In 2005, events brought him to the beating heart of a longtime struggle in US education, what constitutes the science of the story of human origins? That year the Kitzmiller versus Dover Area School District trial set the stage for a national debate on the constitutionality of teaching intelligent design as an alternative to evolution. 

Speaker 6: 

William Buckingham is head of the curriculum committee for the Dover school district. He's also a board member. He strongly believes creationism needs to be taught in the classroom. 

William Buckingham: 

My opinion that it's okay to teach Darwin but you have to balance it with something else such as creationism. 

Speaker 8: 

If we're in a science classroom, which biology is, you should teach science and the theory of evolution is scientific and there's proof of it and creation is based solely on faith. 

Alex Schein: 

In the lead up to the trial, Weisberg and Paul Sniegowski, who you'll hear from later, co-authored a letter in support of the teachers who argued that intelligent design should not be part of the science curriculum. 

Michael Weisberg: 

2005, the Dover case is a contemporary, some people called a contemporary Scopes trial. Contemporary case of creationism in the United States and it's very interesting because for me, it put me on a journey as public in understanding an engagement of science being a major part of my work. But what happened was that Paul Sniegowski, now the Dean of the College and I were both younger professors and in the biology department, me in philosophy. We had already become friends and we were kind of watching the case unfold and what really struck us, were the teachers in the school district who had spoken out against teaching creationism and recognizing in a small town, how hard this must have been, how isolating and alienating this must've been. Our first conversation, we need to do something to support these teachers. What we could do as small as it was, was to write this letter, supporting the teachers 

and saying, we think they're on the right track. We're trying to speak with some authority from the point of view of the university but really trying to kind of put it in their court and say, "We have your back." 

And then through doing that, I got to know a bit over the years, some of the attorneys involved in the case and we had discussions with them about different ways to approach things. And a lot of my training came into play because some of the issues at stake were what is science? What are good scientific methods? Why intelligent design, this form of creationism at stake in the case, why that's not equivalent to teaching evolution and so forth. And then what came of that for me at least, was I got very interested in doing empirical research on public understanding of science, especially evolution. And as time has gone on, I've gotten more interested in climate change. My own work on that really came out of that experience of the Dover case. 

Alex Schein: 

In addition to being a target in the culture wars, Weisberg notes another reason why evolution is so widely misunderstood, it's just complicated. 

Michael Weisberg: 

It is difficult to understand evolution. And one of the things that we've learned is even people who say that they accept evolution, don't understand it all that well. I'm interested both in acceptance of evolution but also in understanding. It's not the case that you find so many people understanding it really well that reject it, but you also find plenty of people who say that they accept evolution but they don't really understand very much about what it means or have very kind of a confused set of ideas about it. 

Alex Schein: 

The connection between some varieties of political and religious identity and denial of the science of evolution is clear, which may lead to the conclusion that there are belief systems that just can't be reconciled. But Weisberg wanted to examine whether simply knowing more about the science makes a difference. 

Michael Weisberg: 

There was a conventional wisdom and I think there probably still is that in these polarized areas of science, what people say to the Gallup organization about whether they accept evolution or climate change was essentially driven entirely by matters of identity. Political identity, religious identity, things like that. And I always thought that that can't be the whole story. I certainly believe it's part of the story but the idea that what you know about the sciences has no correlation with your acceptance, I didn't buy it. We've been engaged for a couple of years, last couple of years in research trying to look more carefully at that question. Primarily for evolution but increasingly also for climate. We actually looked at a couple of issues. The first thing was we were concerned with evolution. That the way that the question was being asked about accepting evolution was partly driving the result about showing that only 40% of Americans except evolution. 

We're not the first people to have noted that. It turns out it is very sensitive to how you ask the question. The way that the most common form of questions have to do with human evolution, which if anything's going to be difficult to accept for a highly religious person, it's going to be human evolution. 

This was even true in Darwin's time. And also the way that the evolutionary option is presented to people, it makes it look like you have to be an atheist to accept it because of the standard wording of the question, something like, do you think that humans were created pretty much in their current form sometime in the last 10,000 years? That's the kind of creation option. Or humans evolved over time and God had nothing to do with it. That's the kind of evolutionist answer. If you read that question carefully, it doesn't say, "And God doesn't exist," but hearing it quickly as you would in a poll, you might sort of see it as being implied that this question just implies atheism directly. 

We worked a lot on refining those kinds of questions. How are we going to ask it. We also introduced a fourth option instead of the standard three that are given. And then we also noted that in existing surveys about people's understanding of evolution, the actual knowledge of evolution, what you might learn in biology course, they were either extremely simple or extremely hard. With the really hard one it was sort of looking at biology class level knowledge of evolution. And the simple questions were just really easy to answer correctly, even by just kind of guessing. We worked really hard to develop a set of questions that could spread people out like a good exam and a good survey that you could really see the distribution of knowledge in different people. When you do those things, when you kind of make the questions a little bit more refined and then you give this kind of more subtle instrument about knowledge and then you administer it to a national audience because a lot of the more careful work is done with the sorts of subjects that researchers can usually get access, to meaning undergraduates. 

We were able to get a grant to use a survey firm and use the national population. Once you do that, you actually do see a correlation between understanding of evolution and acceptance. And even more interestingly, while there's still a huge effect of political and religious identity on evolution, the more you know about it, it attenuates that effect. Someone who's extremely knowledgeable about evolution and is nevertheless an evangelical Christian is much more likely to be an evolutionist than someone that doesn't. It's an interesting interaction. Then we did the same thing with knowledge of what I teach philosophy of science, knowledge of scientific method and same kind of result. That there's still of course, this big primary effect about political and religious ideology but the more you understand about how science works in general, strongly attenuates that polarization. 

Alex Schein: 

The need to understand what science has to tell us isn't just about what we teach children in schools. Weisberg is concerned that the tendency is to deny or misrepresent science like we saw in the Dover vs Kitzmiller case, could have some frightening implications as we address existential threats like climate change. 

Michael Weisberg: 

I'm an optimistic person. I work on climate policy, you have to be, but I do really worry that we had to take relatively simple steps in terms of collective action to get COVID under control and I think it's fair to say we completely failed. Of course, we had a failure of leadership at the top in the United States but it wasn't just that. This issue became politicized in real time. Didn't need to happen. And climate change is not only a much bigger threat in the long run but it also has the problem that you're not going to see for long time images on TV of morgue trailers or in Ecuador, a city I know really well, that we saw images of TV of they ran out of coffins so they used cardboard boxes as coffins. 

And if that kind of image didn't motivate people to take super simple steps like wearing a mask, climate change is going to require much larger changes to behavior. And if we can't find ways of just baking that in, in the background without people noticing then I really worry that we're not going to be able to take action in time. 

Alex Schein: 

With these stakes, there is no walking away from the task of finding bridges and working to help people understand what science has to say. Weisberg sees both opportunities and challenges in approaching this communication problem. 

Michael Weisberg: 

When you want to change things that get tied to matters of identity, you need to think about social norm change and you need to think about who the right messenger is. And it's more. It would be great, I'm an educator and it would be great to think it's just a matter of education but that's only part of the story. And you have to think a lot about how the message is being broadcast and who's broadcasting it and how trustworthy they seem. And because they've presented it in a positive valance, is it all about doom and gloom? Or can people actually have hope? 

I actually really liked the framework that Michael Mann, who's a climate scientist and quite a gifted communicator, he says we should convey that there's urgency but also agency, because if people don't see it as urgent, then they won't take action. But also if people don't see that they could have any agency, they won't take action. We'll just become nihilistic about it. I think that those kinds of considerations, which are complimentary to the things that we've done, I take to be hugely important and often not thought about as much as they should be. 

Alex Schein: 

The Kitzmiller versus Dover case set Michael Weisberg down a path of research on what people understand about evolution. Paul Sniegowski, who was Weisberg's co-author on the letter in support of the teachers in that case, understands a lot about evolution. Sniegowski is a professor of biology and is also the Stephen A. Levin Family Dean of the College of Arts and Sciences. He studies evolutionary genetics, a broad field that combines modern genetic science with Darwinian evolution. Professor Sniegowski references the person who started at all, Charles Darwin for a basic definition of evolution. 

Paul Sniegowski: 

There's a broader definition that I use in my first year seminar and it's actually the definition that Charles Darwin used. In fact, in Darwin's most famous book, On the Origin of Species, he doesn't use the word “evolution” or “evolved” until the last word in the book. "Have been and are being evolved," that's the last word in the book. His phrase for the process is descent with the modifications. And so that's a very easy one to grasp. You have a population of organisms and as they go through lines of descent, that population becomes modified and that's evolution. 

Alex Schein: 

Speaking from his perspective as an expert in evolutionary genetics, there is, as you might expect a much more nuanced explanation of evolution that he teaches in his classes. 

Paul Sniegowski: 

In the genetic perspective, the definition of evolution is a change in the genetic composition of a population of organisms over time across generations. And we define it more precisely in the mathematical models of evolution at the genetic level, as a change in the frequencies of genes, which are DNA or in the case of some viruses, RNA sequences in the genomes of organisms. And those frequencies are the number of individuals carrying a particular form of gene in the population. 

For example, you might imagine a population of humans in which there's a gene for some eye color. Technically we call a variety of a gene an allele. It's an allele for some eye color. And at some point in time being a generation in time in that population, that allele is at a frequency of 40% and if at some later generation, say five generations later, the frequency of that allele is 45%, by definition, the population has evolved at the genetic level. And of course there are genes and alleles that affect all kinds of features in a population, physical features in a population and they all could be changing in frequency and have over time. 

Alex Schein: 

This explanation rests on a solid scientific foundation, a figurative mountain of evidence accumulated over years of observations and research. The science is unambiguous but despite this clarity, the alternate explanations persist, which is why Professor Sniegowski felt compelled to join forces with Michael Weisberg and speak out in Kitzmiller versus Dover. 

Paul Sniegowski: 

This was back in, when was it? 2005, it seems like a long time ago now but these sorts of things are still going on. There were a number of motivations. I think for me, the most important one was thinking about what students are taught as science in the schools. And this was remember, about the public schools in the Dover area school district, near Harrisburg, Pennsylvania. In the end, this is a concern as well in private schools but there's no legal leverage over private schools in the way there is with public schools. With public schools, there's all such sort of creationism related cases, in the end turn out to be in one way or another about the establishment clause of the First Amendment to the US Constitution, Congress shall make no law respecting freedom of religion or the practice thereof. And so it was clear to a number of us as we read about this case that the school board was trying to foist on students as an alternative to real science, a form of creationism, this thing called intelligent design. 

And I think one of the things that got me so interested in it right from the start was that back in those days, I was teaching our introductory evolution course in the biology department and the first lecture or two in my course, I spend on the historical basis of evolution and what came before it and in the early 19th century, the theory of intelligent design. It was then called natural theology and there was someone named William Paley who wrote a book. Intelligent design was a sort of old idea resurrected by people who were sort of fancying it up in molecular language for the 21st century. 

Alex Schein: 

What we teach students about science, their ability to interpret scientific findings in their later lives and where we are now in our response to COVID-19 is a path that is painfully clear to Professor Sniegowski. 

Paul Sniegowski: 

Being able to think clearly about science and the uncertainties of science and the things that are more reliable in science has been an enormous part of dealing with the COVID-19 pandemic and what we're going through right now, as we speak, late August 2021, with the emergence of the Delta strain is a spectacular and brutal example of evolution in real time. 

Alex Schein: 

The need for scientists to step up and defend the science of evolution is perhaps puzzling, certainly to scientists, given the constant stream of important new science showing evolution at work. Professor Sniegowski discussed recent research from his colleague in the biology department, Sarah Tishkoff, she's the David and Lyn Silfen University Professor and a noted expert on genomic variation, human evolution and disease risk in global populations. 

Paul Sniegowski: 

She studies the genetic basis of evolution in humans in recent time. And one of her big discoveries was the spread of what's called lactase persistence in human populations. Almost all humans are born with the ability to digest lactose, which is the sugar that's in a maternal milk and many of us lose this as we get older. And in certain human populations, the loss of lactase expression was the common thing but in a population that's raising milk producing animals and can get protein and carbohydrates and fat from drinking that milk, the capacity to digest lactose would be a good thing and should be favored. And so what Sarah has studied is the spread of lactase persistence, the persistence of the ability and the genetic basis of that as it spread through human populations that took up dairy farming. And there are all kinds of other examples. 

Alex Schein: 

What is it that makes it so hard for the typical person to make the leap from small invisible changes, what Professor Sniegowski calls microevolution, to macro evolution, the really big changes? How do you get from microbes to dogs, to humans, to elephants? 

Paul Sniegowski: 

In the colloquial sense, when people say humans aren't evolving, they're looking for really big changes. Remember that evolution much of the time, not all of the time but much of the time is gradual and occurs at a kind of tempo that our puny lifespans, our awareness of time maybe spans about a 100 years as individuals. We maybe remember our grandparents, if we're lucky, we'll see our grandchildren, that kind of thing. That's almost nothing in evolutionary terms. And so it really requires delving into longer periods of time and really carefully looking at populations and at their genetics. And then what you see is abundant evidence of evolution in human populations and other populations. In fact, it's a really burgeoning field in evolutionary biology now to look at the evolution of natural populations of things like lizards and birds and all kinds of other creatures. We can actually, if we go out there and we look carefully, we can see them changing from year to year. 

Alex Schein: 

Even though changes like these can be observed and are being documented, the fact remains there are a lot of people who run into conceptual blocks when it comes to accepting or even understanding the science of evolution. 

Paul Sniegowski: 

How do you get from microbes to dogs, to humans, to elephant? These are huge changes. And so it will certainly always be the case that we won't see those huge changes in real time, within single human lifetimes. They play out over vast amounts of time. And so when I teach evolution, I still teach a first year seminar on evolution. The very first thing we start by talking about is something that's come to be called deep time. How old really is Earth? It is staggeringly old and for a major fraction of the time it's been in existence, we're pretty sure there've been living things. For about 3.8 billion with a B years, there have been living things on Earth. I assign the students an essay, I ask them to come up with an analogy to time pointing out how brief human civilization or the existence of Homo sapiens, one of the human species that arose in the past few million years has been compared to the entirety of time that Earth has been existence or even as long as we think life has been on Earth. It's a staggeringly large amount of time. 

When you put that realization of the staggeringly large amount of time together with the realization that all populations always are evolving, you can even do calculations and ask yourself how much time would it have taken to accumulate all of the different new gene sequences that have gone to make up the human genome from some ancestor genome? There's been more than enough time. And the problem for people is that we can't observe it directly. 

Alex Schein: 

The concept of deep time isn't easy to grasp. The term itself originated as a way of implying the vastness of geologic time. But it's one thing to recognize that the universe is unimaginably old and another very different thing to understand the implication of time on this scale as applied to living organisms and DNA. 

Paul Sniegowski: 

The biological subject that requires an understanding of deep time and an extrapolation of what occurred without being there personally, that gives people more trouble than star evolution or geology or other things that also require the same sort of logic. One way of thinking of it is what happens for an evolutionary biologist reconstructing the deep past of Earth's life is similar to what happens for a forensics detective. You arrive on the scene and you can infer from the evidence that's there, what's likely to have happened. And in the case of evolution, that evidence is fossils, it's rock layers and nowadays it's divergence among the DNA and genomes and all kinds of other lines of evidence. It all points to the same conclusion. 

Alex Schein: 

Understanding evolution requires engaging with some difficult concepts and the narrative it offers challenges some religious and political identities. But Professor Sniegowski notes that it's a problem when people aren't willing to engage and to entertain challenges to their beliefs. 

Paul Sniegowski: 

We should be interested in what the reliable truth about the natural world is. And if that reliable truth about the natural world makes us uncomfortable, then we should probably make some adjustments to our attitudes. And again, here we can talk about COVID. We should be interested in what the reliable truth about the Delta strain is about COVID, about the efficacy of vaccines and masking. And if we don't like those things that doesn't change what's the reliable truth about them. And so we should ask 

ourselves, should we act in accordance with what we reliably know about the world? And in my view, the answer is yes, we should. 

And it's really no different with something like evolution as well. Let me just say that that doesn't preclude religious belief and I always point this out to my students but at the same time, I say to them, "There are going to be times when evolution or some other aspect of modern science makes you scratch your head and feel like your religious beliefs or other beliefs about the world are being challenged. It should do that. And in fact, if you aren't scratching your head and feeling challenged once in a while, you're not thinking hard enough." 

Alex Schein: 

Looking at the bigger picture, Professor Sniegowski would hope for people to have a better understanding, not just about evolution but about science as a process that leads us closer and closer to certainty. 

Paul Sniegowski: 

I think that one of the hang-ups that people can have with the sciences is that they think that scientific knowledge is either certain or it's no good. You either know for sure, 100%, or what you're working on is no good. If you have the slightest degree of uncertainty, that's not science, couldn't be farther from the truth. The truth is when you're right out there on the edge of a scientific field, well, by definition out there on the edge, you don't know for certain and you're trying to find out new things. And as you find out new things, some of them wash away and are not reliable. Others turn out to be reliable and may over time become more and more and more reliable to the point where we approach a kind of sense of certainty about them. 

Evolution is in that category. But if we don't have complete certainty about something, that doesn't mean its unscientific. In fact, it is very much in the nature of science to trade in uncertainty from day to day. And it's an understanding of the relationship between sort of the reliability of our knowledge and the process of making it better that we really owe our students. We really owe teaching our students both at the college level and before, about this process. A process of thinking, experimenting, testing, getting data. It's an ongoing thing. 

Alex Schein: 

This concludes episode three of In These Times, Fear and Loathing and Science. Join us for episode four, Your Brain on Drugs. We'll be speaking with psychology professor Martha Farah about the implications of brain enhancements and what we can learn from science fiction. 

The OMNIA Podcast is a production of Penn Arts and Sciences. Thanks to professors Paul Sniegowski and Michael Weisberg. I'm Alex Schein. Thanks for listening. Be sure to subscribe to the OMNIA Podcast by Penn Arts and Sciences on Apple iTunes or wherever you find your podcasts to listen to all seven episodes of season three of In These Times, Fear and Loathing and Science.