Notes in practical evolution

7 minute read

A lot of academic-oriented bloggers write about what they do in their classes. I don’t often blog about my teaching. Mainly, I like to keep my class activities between me and my students – I don’t want them to think they’ll be reading about themselves outside of class. If I discuss questions I’ve asked in class and the students’ responses to them, I don’t want to have to stop and think whether I’ve presented things the same way, or inhibit people from speaking up and participating in class in any way. And participating in class is the most important thing – if a student thought he could read my blog instead of going to class, that would be really bad for my pedagogy!

But I’m going to make some exceptions in the next few months. Classes are over, and a couple of ideas from readers have me thinking about writing and teaching. Earlier this week, I wrote some thoughts about the lack of evolution understanding among scientists and educators.

There are a large group of "science-friendly" people who do not understand evolutionary biology, and who do not have a practical idea of its importance. These people are without a doubt against teaching creationism in science courses, but they cannot be for evolution except in the most nebulous sense, because they have no more than a nebulous idea of what evolution is. Unfortunately, some professional biologists, geneticists, and other scientists are among this group.

In response, a reader wrote:

What would be very helpful to that group -- or really, to those who attempt to brief that group -- is a summary that addresses those issues in a reasonably succinct manner. How about it?

In addition to this, the linked articles above illustrate the problem that non-science educators lack a basic understanding of science, what it is, and what scientists do.


Another reader sent a reference to the Chronicle of Higher Education, which ran an article about science education for nonmajors (sorry, no link). The article featured the annual science literacy survey run by Michigan State political scientist Jon Miller. There’s the usual spate of bad news (only 40 percent of people believe humans evolved, only 63 percent know that the Earth’s orbital period is a year, etc…). But then there is this:

But behind those disturbing numbers lie another, more encouraging, set of poll results intimately tied to the college curriculum. Americans' overall score in science literacy ranks second in the world among developed nations, behind only Sweden. That is in large part because of this country's unusual system of requiring many nonscience majors to take at least some science courses, says Jon D. Miller, a political scientist at Michigan State University who has led the survey for more than 20 years.
Mr. Miller also found that college course work in science was the factor most strongly predictive of a passing score on the survey, ahead of others like reading science magazines.
In other words, courses for nonmajors -- sometimes derided by professors and students as "Rocks for Jocks" and "Physics for Poets" and as presenting watered-down fluff -- may deserve more respect.

Well, I teach two large undergraduate courses, with a mixture of majors and non-majors. And I generally have a large fraction of non-majors in my upper level courses. I always try to convey that common sense aspect of scientific theories. Theories are shorthand for facts: they help us predict which things are impossible and which are likely.

When students complain about required courses, they generally cannot identify the course’s relevance for their future life. I can’t succeed with everyone, but I manage to show a large proportion that evolution and genetics are important. The Chronicle article discusses a number of ways that instructors try to do that – it focuses on physics teachers for some reason. But everyone I know who’s been teaching science for a while has strategies along these lines.


I‘m going to start a series of articles about the common sense aspect of evolutionary theory. What about evolution is actually practical knowledge? How can it help people understand things relevant to their own work or lives? This goes beyond the gee-whiz, “Where do we come from,” National Geographic-kind of interesting question. That’s nothing more than a framework for idle curiosity: it presents evolution as a kind of adjunct or substitute for religious inquiry.

I want to convey something more important. It matters that we evolved. The process of evolution allows scientific predictions that we can use to make things happen, to make them work. Evolutionary biology illustrates and informs us about decisions that society will have to make in the next 20 years; decisions that I want my students to be informed about.

When I teach evolution, I emphasize a common sense perspective. Understanding a science means knowing the boundaries of the possible. Biologists sometimes say that anything might be possible in biology – it is, after all, highly dependent on historical events that might have turned out very differently. But while it’s true that a wide range of things might have happened, it is not true that anything at all might have happened. Knowing evolutionary theory – including its mathematical basis – lets us understand the limits of the possible, the likely, and the fundamental trade-offs that balance them.

I can’t promise that every example I describe will outline a practical problem, but they will all apply to the problems that face us today. Gene testing, behavioral modification, conservation, biotechnology, global warming – all those are problems that demand not only economic logic but also biological logic

  1. Should we be worried about the polar bears?

  2. Up to sixteen percent of American elementary students are categorized as ADD/ADHD. This diagnosis often comes with additional investment and help with learning, but also with social stigmatization and pressure to take pharmaceuticals such as Ritalin and Adderall. If this behavior pattern is so bad, why does it exist?

  3. The U. S. government routinely recommends high consumption of dairy foods on the part of its citizens, for a healthy life. Yet vast majority of the world’s adult population, including millions of Americans, exhibit ill effects from drinking whole milk, and certain milk products, in the recommended amounts. Why?

  4. Honeybees are dying. So are frogs. Is it a crisis? Why is it happening?

  5. Geneticists are finding alleles that contribute to the risk of chronic diseases like cardiovascular disease, lung cancer, and diabetes. Many of these alleles occur in a few populations but not others – for instance, Europeans versus Africans. Why?

  6. We are told that polar bears are endangered because of global warming. Yet some people claim that polar bears are simply brown bears underneath the fur. Are they right? Does it matter?

  7. The ratio of boy births to girl births varies among human populations. Some of this variation is natural, some is influenced by human practices such as selective abortion. How can we tell which is which?

  8. Corn (maize) is increasingly important to the world’s economy. It is the single largest mode of converting solar energy into starch, making it useful for food, feedstock, and ethanol conversion. Maize is a new species, which has existed for less than 10,000 years. How did this happen? What more is possible?

  9. The number of known primate species has vastly increased during the past 30 years. Yet almost none of these represent populations new to science. What gives?

  10. Some futurists are predicting a coming “singularity,” in which humans merge with unimaginably intelligent machines to create a future beyond the scope of any current predictions. What does our past evolution say about this prospect?

My series will be covering many of these topics and many others. I’ll be drawing from human genetics, ecology, agricultural sciences, geology, paleontology, and history. Remember that my audience is broad, so if you’ve seen part of one of my stories before, I apologize – most people probably don’t know the story, and most of my readers haven’t been following the blog since it started.

Where possible, I’ll draw things back toward humans. No, I don’t think humans are always the most important topic in evolutionary biology. But let’s face it: I’m an anthropologist!

I plan to publish an essay here every Friday for the foreseeable future. You’ll see this along with a number of other changes here next week. I apologize for a week of little posting, but as you’ll see, I have had a little preparing to do!