Is it possible to teach evolutionary biology “sensitively”?

Michael Reiss, a professor of science education at University College London and an Anglican Priest, suggests that “we need to rethink the way we teach evolution” largely because conventional approaches can be unduly confrontational and “force religious children to choose between their faith and evolution” or to result in students who”refuse to engage with a lesson.” He suggests that a better strategy would be akin to those use to teach a range of “sensitive” subjects “such as sex, pornography, ethnicity, religion, death studies, terrorism, and others” and could “help some students to consider evolution as a possibility who would otherwise not do so.” [link to his original essay and a previous post on teaching evolution: Go ahead and teach the controversy].

There is no doubt that an effective teacher attempts to present materials sensitively; it is the rare person who will listen to someone who “teaches” ideas in a hostile, alienating, or condescending manner. That said, it can be difficult to avoid the disturbing implications of scientific ideas, implications that can be a barrier to their acceptance. The scientific conclusion that males and females are different but basically the same can upset people on various sides of the theo-political spectrum. 

In point of fact an effective teacher, a teacher who encourages students to question their long held, or perhaps better put, familial or community beliefs, can cause serious social push-back  – Trouble with a capital T.  It is difficult to imagine a more effective teacher than Socrates (~470-399 BCE). Socrates “was found guilty of ‘impiety’ and ‘corrupting the young’, sentenced to death” in part because he was an effective teacher (see Socrates was guilty as charged).  In a religious and political context, challenging accepted Truths (again with a capital T) can be a crime.  In Socrates’ case”Athenians probably genuinely felt that undesirables in their midst had offended Zeus and his fellow deities,” and that, “Socrates, an unconventional thinker who questioned the legitimacy and authority of many of the accepted gods, fitted that bill.”  

So we need to ask of scientists and science instructors, does the presentation of a scientific, that is, a naturalistic and non-supernatural, perspective in and of itself represent an insensitivity to those with a super-natural belief system. Here it is worth noting a point made by the philosopher John Gray, that such systems extend beyond those based on a belief in god(s); they include those who believe, with apocalyptic certainty, in any of a number of Truths, ranging from the triumph of a master race, the forced sterilization of the unfit, the dictatorship of the proletariat, to history’s end in a glorious capitalist and technological utopia. Is a science or science instruction that is “sensitive” to, that is, uncritical of or upsetting to those who hold such beliefs, possible? 

My original impression is that one’s answer to this question is likely to be determined by whether one considers science a path to Truth, with a purposeful capital T, or rather that the goal of scientists is to build a working understanding of the world around and within us.  Working scientists, and particularly biologists who must daily confront the implications of apparently un-intelligent designed organisms (due to ways evolution works) are well aware that absolute certainty is counterproductive. Nevertheless, the proven explanatory and technological power of the scientific enterprise cannot help but reinforce the strong impression that there is some deep link between scientific ideas and the way the world really works.  And while some scientists have advocated unscientific speculations (think multiverses and cosmic consciousness), the truth, with a small t, of scientific thinking is all around us.  

Photograph of the Milky Way by Tim Carl photography, used by permission 

 A science-based appreciation of the unimaginable size and age of the universe, taken together with compelling evidence for the relatively recent appearance of humans (Homo sapiens from their metazoan, vertebrate, tetrapod, mammalian, and primate ancestors) cannot help but impact our thinking as to our significance in the grand scheme of things (assuming that there is such a, possibly ineffable, plan)(1). The demonstrably random processes of mutation and the generally ruthless logic by which organisms survive, reproduce, and evolve, can lead even the most optimistic to question whether existence has any real meaning.  

Consider, as an example, the potential implications of the progress being made in terms of computer-based artificial intelligence, together with advances in our understanding of the molecular and cellular connection networks that underlie human consciousness and self-consciousness. It is a small step to conclude, implicitly or explicitly, that humans (and all other organisms with a nervous system) are “just” wet machines that can (and perhaps should) be controlled and manipulated. The premise, the “self-evident truth”, that humans should be valued in and of themselves, and that their rights should be respected (2) is eroded by the ability of machines to perform what were previously thought to be exclusively human behaviors. 

Humans and their societies have, after all, been around for only a few tens of thousands of years.  During this time, human social organizations have passed from small wandering bands influenced by evolutionary kin and group selection processes to produce various social systems, ranging from more or less functional democracies, pseudo-democracies (including our own growing plutocracy), dictatorships, some religion-based, and totalitarian police states.  Whether humans have a long term future (compared to the millions of years that dinosaurs dominated life on Earth) remains to be seen – although we can be reasonably sure that the Earth, and many of its non-human inhabitants, will continue to exist and evolve for millions to billions of years, at least until the Sun explodes. 

So how do we teach scientific conclusions and their empirical foundations, which combine to argue that science represents how the world really works, without upsetting the most religiously and politically fanatical among us?  Those who most vehemently reject scientific thinking because they are the most threatened by its apparently unavoidable implications. The answer is open to debate, but to my mind it involves teaching students (and encouraging the public) to distinguish empirically-based, and so inherently limited observations and the logical, coherent, and testable scientific models they give rise to from unquestionable TRUTH- and revelation-based belief systems. Perhaps we need to focus explicitly on the value of science rather than its “Truth”. To reinforce what science is ultimately for; what justifies society’s support for it, namely to help reduce human suffering and (where it makes sense) to enhance the human experience, goals anchored in the perhaps logically unjustifiable, but nevertheless essential acceptance of the inherent value of each person.   

  1. Apologies to “Good Omens”
  2. For example, “We hold these truths to be self-evident, that all men are created equal, that they are endowed by their creator with certain unalienable rights, that among these are life, liberty and the pursuit of happiness.” 

Science “awareness” versus “literacy” and why it matters, politically.

Montaigne concludes, like Socrates, that ignorance aware of itself is the only true knowledge”  – from “forbidden knowledge” by Roger Shattuck

A month or so ago we were treated to a flurry of media excitement surrounding the release of the latest Pew Research survey on Americans’ scientific knowledge.  The results of such surveys have been interpreted to mean many things. As an example, the title of Maggie Koerth-Baker’s short essay for the 538 web site was a surprising “Americans are Smart about Science”, a conclusion not universally accepted (see also).  Koerth-Baker was taken by the observation that the survey’s results support a conclusion that Americans’ display “pretty decent scientific literacy”.  Other studies (see Drummond & Fischhoff 2017) report that one’s ability to recognize scientifically established statements does not necessarily correlate with the acceptance of science policies – on average climate change “deniers” scored as well on the survey as “acceptors”.  In this light, it is worth noting that science-based policy pronouncements generally involve projections of what the future will bring, rather than what exactly is happening now.  Perhaps more surprisingly, greater “science literacy” correlates with more polarized beliefs that, given the tentative nature of scientific understanding –which is not about truth per se but practical knowledge–suggests that the surveys’ measure something other than scientific literacy.  While I have written on the subject before  it seems worth revisiting – particularly since since then I have read Rosling’s FactFullness and thought more about the apocalyptic bases of many secular and religious movements, described in detail by the historian Norman Cohn and the philosopher John Gray and gained a few, I hope, potentially useful insights on the matter.  

First, to understand what the survey reports we should take a look at the questions asked and decide what the ability to chose correctly implies about scientific literacy, as generally claimed, or something simpler – perhaps familiarity.  It is worth recognizing that all such instruments, particularly  those that are multiple choice in format, are proxies for a more detailed, time consuming, and costly Socratic interrogation designed to probe the depth of a persons’ knowledge and understanding.  In the Pew (and most other such surveys) choosing the correct response implies familiarity with various topics impacted by scientific observations. They do not necessarily reveal whether or not the respondent understands where the ideas come from, why they are the preferred response, or exactly where and when they are relevant (2). So is “getting the questions correct” demonstrates a familiarity with the language of science and some basic observations and principles but not the limits of respondents’ understanding.  

Take for example the question on antibiotic resistance (→).  The correct answer “it can lead to antibiotic-resistant bacteria” does not reveal whether the respondent understands the evolutionary (selective) basis for this effect, that is random mutagenesis (or horizontal gene transfer) and antibiotic-resistance based survival.  It is imaginable that a fundamentalist religious creationist could select the correct answer based on  plausible, non-evolutionary mechanisms (3).  In a different light, the question on oil, natural gas and coal (↓) could be seen as ambiguous – aren’t these all derived from long dead organisms, so couldn’t they reasonably be termed biofuels?  

While there are issues with almost any such multiple choice survey instrument, surely we would agree that choosing the “correct” answers to these 11 questions reflects some awareness of current scientific ideas and terminologies.  Certainly knowing (I think) that a base can neutralize and acid leaves unresolved how exactly the two interact, that is what chemical reaction is going on, not to mention what is going on in the stomach and upper gastrointestinal tract of a human being.  In this case, selecting the correct answer is not likely to conflict with one’s view of anthropogenic effects on climate, sex versus gender, or whether one has an up to date understanding of the mechanisms of immunity and brain development, or the social dynamics behind vaccination – specifically the responsibilities that members of a social group have to one another.   

But perhaps a more relevant point is our understanding of how science deals with the subject of predictions, because at the end of the day it is these predictions that may directly impact people in personal, political, and economically impactful ways. 

We can, I think, usefully divide scientific predictions into two general classes.  There are predictions about a system that can be immediately confirmed or dismissed through direct experiment and observation and those that cannot. The immediate (accessible) type of prediction is the standard model of scientific hypothesis testing, an approach that reveals errors or omissions in one’s understanding of a system or process.  Generally these are the empirical drivers of theoretical understanding (although perhaps not in some areas of physics).  The second type of prediction is inherently more problematic, as it deals with the currently unobservable future (or the distant past).  We use our current understanding of the system, and various assumptions, to build a predictive model of the system’s future behavior (or past events), and then wait to see if they are confirmed. In the case of models about the past, we often have to wait for a fortuitous discovery, for example the discovery of a fossil that might support or disprove our model.   

It’s tough to make predictions, especially about the future
– Yogi Berra (apparently)

Anthropogenic effects on climate are an example of the second type of prediction. No matter our level of confidence, we cannot be completely sure our model is accurate until the future arrives. Nevertheless, there is a marked human tendency to take predictions, typically about the end of the world or the future of the stock market, very seriously and to make urgent decisions based upon them. In many cases, these predictions impact only ourselves, they are personal.  In the case of climate change, however, they are likely to have disruptive effects that impact many. Part of the concern about study predictions is that responses to these predictions will have immediate impacts, they produce social and economic winners and losers whether or not the predictions are confirmed by events. As Hans Rosling points out in his book Factfullness, there is an urge to take urgent, drastic, and pro-active actions in the face of perceived (predicted) threats.  These recurrent and urgent calls to action (not unlike repeated, and unfulfilled predictions of the apocalypse) can lead to fatigue with the eventual dismissal of important warnings; warnings that should influence albeit perhaps not dictate ecological-economic and political policy decisions.  

Footnotes and literature cited:
1. As a Pew Biomedical Scholar, I feel some peripheral responsibility for the impact of these reports

2. As pointed out in a forthcoming review, the quality of the distractors, that is the incorrect choices, can dramatically impact the conclusions derived from such instruments. 

3.  I won’t say intelligent design creationist, as that makes no sense. Organisms are clearly not intelligently designed, as anyone familiar with their workings can attest

Drummond, C. & B. Fischhoff (2017). “Individuals with greater science literacy and education have more polarized beliefs on controversial science topics.” Proceedings of the National Academy of Sciences 114: 9587-9592.


Visualizing and teaching evolution through synteny

Embracing the rationalist and empirically-based perspective of science is not easy. Modern science generates disconcerting ideas that can be difficult to accept and often upsetting to philosophical or religious views of what gives meaning to existence [link]. In the context of evolutionary mechanisms within biology, the fact that variation is generated by random (stochastic) events, unpredictable at the level of the individual or within small populations, led to the rejection of Darwinian principles by many working scientists around the turn of the 20th century (see Bowler’s The Eclipse of Darwinism + link).  Educational research studies, such as our own “Understanding randomness and its impact on student learning“, reinforce the fact that ideas involving stochastic processes are relevant to evolutionary, as well as cellular and molecular, biology and are inherently difficult for people to accept (see also: Why being human makes evolution hard to understand). Yet there is no escape from the science-based conclusion that stochastic events provide the raw material upon which evolutionary mechanisms act, as well as playing a key role in a wide range of molecular and cellular level processes, including the origin of various diseases, particularly cancer [Cancer is partly caused by bad luck](1).

All of which leaves the critical question, at least for educators, of how to best teach students about evolutionary mechanisms and outcomes. The problem becomes all the more urgent given the anti-science posturing of politicians and public “intellectuals”, on both the right and the left, together with various overt and covert attacks on the integrity of science education, such as a new Florida law that lets “anyone in Florida challenge what’s taught in schools”.

Just to be clear, we are not looking for students to simply “believe” in the role of evolutionary processes in generating the diversity of life on Earth, but rather that they develop an understanding of how such processes work and how they make a wide range of observations scientifically intelligible. Of course the end result, unless you are prepared to abandon science altogether, is that you will find yourself forced to seriously consider the implications of unescapable scientific conclusions, no matter how weird and disconcerting they may be.

There are a number of educational strategies, in part depending upon one’s disciplinary perspective, on how to approach teaching evolutionary processes. Here I consider just one, based on my background in cell and molecular biology.  Genomicus is a web tool that “enables users to navigate in genomes in several dimensions: linearly along chromosome axes, transversely across different species, and chronologically along evolutionary time.”  It is one of a number of recently developed web-based resources that make it possible to use the avalanche of DNA (gene and genomic) sequence data being generated by the scientific community. For example, the ExAC Browser enables one to examine genetic variation in over 60,000 unrelated people. Such tools supplement and extend a range of tools accessible through the U.S. National Library of Medicine / NIH / National Center for Biotechnology Information (NCBI) web portal (PubMed).

In the biofundamentals© / coreBio course (with an evolving text available here), we originally used the observation that members of our subfamily of primates,  the Haplorhini or dry nose primates, are, unlike most mammals, dependent on the presence of vitamin C (ascorbic acid) in their diet; without vitamin C we develop scurvy, a potentially lethal condition. While there may be positive reasons for vitamin C dependence, in biofundamentals© we present this observation in the context of small population size and a forgiving environment. A plausible scenario is that the ancestral population of the Haplorhini lost the L-gulonolactone oxidase (GULO) gene (see OMIM) needed for vitamin C synthesis. The remains of the GULO gene found in humans and other Haplorhini genomes is mutated and non-functional, resulting in our requirement for dietary vitamin C.

How, you might ask, can we be so sure? Because we can transfer a functional mouse GULO gene into human cells; the result is that vitamin C dependent human cells become vitamin C independent (see: Functional rescue of vitamin C synthesis deficiency in human cells). This is yet another experimental result, similar to the ability of bacteria to accurately decode a human insulin gene), that supports the explanatory power of an evolutionary perspective (2),


In an environment in which vitamin C is plentiful in a population’s diet, the mutational loss of the GULO gene would be benign, that is, not selected against. In a small population, the stochastic effects of genetic drift can lead to the loss of genetic variants that are not strongly selected for. More to the point, once a gene’s function has been lost due to mutation, it is unlikely, although not impossible, that a subsequent mutation will lead to the repair of the gene. Why? Because there are many more ways to break a molecular machine, such as the GULO enzyme, but only a few ways to repair it. As the ancestor of the Haplorhini diverged from the ancestor of the vitamin C independent Strepsirrhini (wet-nose) group of primates, an event estimated to have occurred around 65 million years ago, its ancestors had to deal with their dietary dependence on vitamin C either by remaining within their original (vitamin C-rich) environment or by adjusting their diet to include an adequate source of vitamin C.

At this point we can start to use Genomicus to examine the results of evolutionary processes (a YouTube video on using Genomicus)(3).  In Genomicus a gene is indicated  by a pointed box  ; for simplicity all genes are drawn as if they are the same size (they are not); different genes get different colors and the direction of the box indicates the direction of RNA synthesis, the first stage of gene expression. Each horizontal line in the diagram below represents a segment of a chromosome from a particular species, while the blue lines to the left represent phylogenic (evolutionary) relationships. If we search for the GULO gene in the mouse, we find it and we discover that its orthologs (closely related genes) can be found in a wide range of eukaryotes, that is, organisms whose cells have a nucleus (humans are eukaryotes).
We find a version of the GULO gene in single-celled eukaryotes, such as baker’s yeast, that appear to have diverged from other eukaryotes about ~1.500,000,000 years ago (1500 million years ago, abbreviated Mya).  Among the mammalian genomes sequenced to date, the genes surrounding the GULO gene are also (largely) the same, a situation known as synteny (mammals are estimated to have shared a common ancestor about 184 Mya). Since genes can move around in a genome without necessarily disrupting their normal function(s), a topic for another day, synteny between distinct organisms is assumed to reflect the organization of genes in their common ancestor. The synteny around the GULO gene, and the presence of a GULO gene in yeast and other distantly related organisms, suggests that the ability to synthesize vitamin C is a trait conserved from the earliest eukaryotic ancestors.

Now a careful examination of this map (↑) reveals the absence of humans (Homo sapiens) and other Haplorhini primates – Whoa!!! what gives?  The explanation is, it turns out, rather simple. Because of mutation, presumably in their common ancestor, there is no functional GULO gene in Haplorhini primates. But the Haplorhini are related to the rest of the mammals, aren’t they?  We can test this assumption (and circumvent the absence of a functional GULO gene) by exploiting synteny – we search for other genes present in the syntenic region (↓). What do we find? We find that this region, with the exception of GULO, is present and conserved in the Haplorhini: the systemic region around the GULO gene lies on human chromosome 8 (highlighted by the red box); the black box indicates the GULO region in the mouse. Similar syntenic regions are found in the homologous (evolutionarily-related) chromosomes of other Haplorhini primates.

The end result of our Genomicus exercise is a set of molecular level observations, unknown to those who built the original anatomy-based classification scheme, that support the evolutionary relationship between the Haplorhini and more broadly among mammals. Based on these observations, we can make a number of unambiguous and readily testable predictions. A newly discovered Haplorhini primate would be predicted to share the same syntenic region and to be missing a functional GULO gene, whereas a newly discovered Strepsirrhini primate (or any mammal that does not require dietary ascorbic acid) should have a functional GULO gene within this syntenic region.  Similarly, we can explain the genomic similarities between those primates closely related to humans, such as the gorilla, gibbon, orangutan, and chimpanzee, as well as to make testable predictions about the genomic organization of extinct relatives, such as Neanderthals and Denisovians, using DNA recovered from fossils [link].

It remains to be seen how best to use these tools in a classroom context and whether having students use such tools influences their working understanding, and more generally, their acceptance of evolutionary mechanisms. That said, this is an approach that enables students to explore real data and to develop  plausible and predictive explanations for a range of genomic discoveries, likely to be relevant both to understanding how humans came to be, and in answering pragmatic questions about the roles of specific mutations and genetic variations in behavior, anatomy, and disease susceptibility.

Some footnotes:

(1) Interested in a magnetic bumper image? visit: http://www.cafepress.com/bioliteracy

(2) An insight completely missing (unpredicted and unexplained) by any creationist / intelligent design approach to biology.

(3) Note, I have no connection that I know of with the Genomicus team, but I thank Tyler Square (soon to be at UC Berkeley) for bringing it to my attention.

The trivialization of science education

It’s time for universities to accept their role in scientific illiteracy.  

There is a growing problem with scientific illiteracy, and its close relative, scientific over-confidence. While understanding science, by which most people seem to mean technological skills, or even the ability to program a device (1), is purported to be a critical competitive factor in our society, we see a parallel explosion of pseudo-scientific beliefs, often religiously held.  Advocates of a gluten-free paleo-diet battle it out with orthodox vegans for a position on the Mount Rushmore of self-righteousness, at the same time astronomers and astrophysicists rebrand themselves as astrobiologists (a currently imaginary discipline) while a subset of theoretical physicists, and the occasional evolutionary biologist, claim to have rendered ethicists and philosophers obsolete (oh, if it were only so). There are many reasons for this situation, most of which are probably innate to the human condition.  Our roots are in the vitamin C-requiring Haplorhini (dry nose) primate family, we were not evolved to think scientifically, and scientific thinking does not come easy for most of us, or for any of us over long periods of time (2). The fact that the sciences are referred to as disciplines reflects this fact, it requires constant vigilance, self-reflection, and the critical skepticism of knowledgeable colleagues to build coherent, predictive, and empirically validated models of the Universe (and ourselves).  In point of fact, it is amazing that our models of the Universe have become so accurate, particularly as they are counter-intuitive and often seem incredible, using the true meaning of the word.

Many social institutions claim to be in the business of developing and supporting scientific literacy and disciplinary expertise, most obviously colleges and universities.  Unfortunately, there are several reasons to question the general efficacy of their efforts and several factors that have led to this failure. There is the general tendency (although exactly how wide-spread is unclear, I cannot find appropriate statistics on this question) of requiring non-science students to take one, two, or more  “natural science” courses, often with associated laboratory sections, as a way to “enhance literacy and knowledge of one or more scientific disciplines, and enhance those reasoning and observing skills that are necessary to evaluate issues with scientific content” (source).

That such a requirement will “enable students to understand the current state of knowledge in at least one scientific discipline, with specific reference to important past discoveries and the directions of current development; to gain experience in scientific observation and measurement, in organizing and quantifying results, in drawing conclusions from data, and in understanding the uncertainties and limitations of the results; and to acquire sufficient general scientific vocabulary and methodology to find additional information about scientific issues, to evaluate it critically, and to make informed decisions” (source) suggests a rather serious level of faculty/institutional distain or apathy for observable learning outcomes, devotional levels of wishful thinking,  or simple hubris.  To my knowledge there is no objective evidence to support the premise that such requirements achieve these outcomes – which renders the benefits of such requirements problematic, to say the least (link).

On the other hand, such requirements have clear and measurable costs; going beyond the simple burden of added and potentially ineffective or off-putting course credit hours. The frequent requirement for multi-hour laboratory courses impacts the ability of students to schedule courses.  It would be an interesting study to examine how, independently of benefit, such laboratory course requirements impact students’ retention and time to degree, that is, bluntly put, costs to students and their families.

Now, if there were objective evidence that taking such courses improved students’ understanding of a specific disciplinary science and its application, perhaps the benefit would warrant the cost.  But one can be forgiven if one assumes a less charitable driver, that is, science departments’ self-interest in using laboratory and other non-major course requirements as means to support graduate students.  Clearly there is a need for objective metrics for scientific, that is disciplinary, literacy and learning outcomes.

And this brings up another cause for concern.  Recently, there has been a movement within the science education research community to attempt to quantify learning in terms of what are known as “forced choice testing instruments;” that is, tests that rely on true/false and multiple-choice questions, an actively anti-Socratic strategy.  In some cases, these tests claim to be research based.  As one involved in the development of such a testing instrument (the Biology Concepts Instrument or BCI), it is clear to me that such tests can serve a useful role in helping to identify areas in which student understanding is weak or confused [example], but whether they can provide an accurate or, at the end of the day, meaningful measure of whether students have developed an accurate working understanding of complex concepts and the broader meaning of observations is problematic at best.

Establishing such a level of understanding relies on Socratic, that is, dynamic and adaptive evaluations: can the learner clearly explain, either to other experts or to other students, the source and implications of their assumptions?  This is the gold standard for monitoring disciplinary understanding. It is being increasingly side-lined by those who rely on forced choice tests to evaluate learning outcomes and to support their favorite pedagogical strategies (examples available upon request).  In point of fact, it is often difficult to discern, in most science education research studies, what students have come to master, what exactly they know, what they can explain and what they can do with their knowledge. Rather unfortunately, this is not a problem restricted to non-majors taking science course requirements; majors can also graduate with a fragmented and partially, or totally, incoherent understanding of key ideas and their empirical foundations.

So what are the common features of a functional understanding of a particular scientific discipline, or more accurately, a sub-discipline?  A few ideas seem relevant.  A proficient needs to be realistic about their own understanding.  We need to teach disciplinary (and general) humility – no one actually understands all aspects of most scientific processes.  This is a point made by Fernbach & Sloman in their recent essay, “Why We Believe Obvious Untruths.”  Humility about our understanding has a number of beneficial aspects.  It helps keep us skeptical when faced with, and asked to accept, sweeping generalizations.

Such skepticism is part of a broader perspective, common among working scientists, namely the ability to distinguish the obvious from the unlikely, the implausible, and the impossible. When considering a scientific claim, the first criterion is whether there is a plausible mechanism that can be called upon to explain it, or does it violate some well-established “law of nature”. Claims of “zero waste” processes butt up against the laws of thermodynamics.

Going further, we need to consider how the observation or conclusions fits with other well established principles, which means that we have to be aware of these principles, as well as acknowledging that we are not universal experts in all aspects of science.  A molecular biologist may recognize that quantum mechanics dictates the geometries of atomic bonding interactions without being able to formally describe the intricacies of the molecule’s wave equation. Similarly, a physicist might think twice before ignoring the evolutionary history of a species, and claiming that quantum mechanics explains consciousness, or that consciousness is a universal property of matter.  Such a level of disciplinary expertise can take extended experience to establish, but is critical to conveying what disciplinary mastery involves to students; it is the major justification for having disciplinary practitioners (professors) as instructors.

From a more prosaic educational perspective other key factors need to be acknowledged, namely a realistic appreciation of what people can learn in the time available to them, while also understanding at least some of their underlying motivations, which is to say that the relevance of a particular course to disciplinary goals or desired educational outcomes needs to be made explicit and as engaging as possible, or at least not overtly off putting, something that can happen when a poor unsuspecting molecular biology major takes a course in macroscopic physics, taught by an instructor who believes organisms are deducible from first principles based on the conditions of the big bang.  Respecting the learner requires that we explicitly acknowledge that an unbridled thirst for an empirical, self-critical, mastery of a discipline is not a basic human trait, although it is something that can be cultivated, and may emerge given proper care.  Understanding the real constraints that act on meaningful learning can help focus courses on what is foundational, and help eliminate the irrelevant or the excessively esoteric.

Unintended consequences arise from “pretending” to teach students, both majors and non-science majors, science. One is an erosion of humility in the face of the complexity of science and our own limited understanding, a point made in a recent National Academy report that linked superficial knowledge with more non-scientific attitudes. The end result is an enhancement of what is known as the Kruger-Dunning effect, the tendency of people to seriously over-estimate their own expertise: “the effect describes the way people who are the least competent at a task often rate their skills as exceptionally high because they are too ignorant to know what it would mean to have the skill”.

A person with a severe case of Kruger-Dunning-itis is likely to lose respect for people who actually know what they are talking about. The importance of true expertise is further eroded and trivialized by the current trend of having photogenic and well-speaking experts in one domain pretend to talk, or rather to pontificate, authoritatively on another (3).  In a world of complex and arcane scientific disciplines, the role of a science guy or gal can promote rather than dispel scientific illiteracy.

We see the effects of the lack of scientific humility when people speak outside of their domain of established expertise to make claims of certainty, a common feature of the conspiracy theorist.  An oft used example is the claim that vaccines cause autism (they don’t), when the actual causes of autism, whether genetic and/or environmental, are currently unknown and the subject of active scientific study.  An honest expert can, in all humility, identify the limits of current knowledge as well as what is known for certain.  Unfortunately, revealing and ameliorating the levels of someone’s Kruger-Dunning-itis involves a civil and constructive Socratic interrogation, something of an endangered species in this day and age, where unseemly certainty and unwarranted posturing have replaced circumspect and critical discourse.  Any useful evaluation of what someone knows demands the time and effort inherent in a Socratic discourse, the willingness to explain how one knows what one thinks one knows, together with a reflective consideration of its implications, and what it is that other trained observers, people demonstrably proficient in the discipline, have concluded. It cannot be replaced by a multiple choice test.

Perhaps a new (old) model of encouraging in students, as well as politicians and pundits, an understanding of where science comes from, the habits of mind involved, the limits of, and constraints on, our current understanding  is needed.  At the college level, courses that replace superficial familiarity and unwarranted certainty with humble self-reflection and intellectual modesty might help treat the symptoms of Kruger-Dunning-itis, even though the underlying disease may be incurable, and perhaps genetically linked to other aspects of human neuronal processing.


some footnotes:

  1. after all, why are rather distinct disciplines lumped together as STEM (science, technology, engineering and mathematics).
  2.  Given the long history of Homo sapiens before the appearance of science, it seems likely that such patterns of thinking are an unintended consequence of selection for some other trait, and the subsequent emergence of (perhaps excessively) complex and self-reflective nervous system.
  3.  Another example of Neil Postman’s premise that education is be replaced by edutainment (see  “Amusing ourselves to Death”.

Go ahead and “teach the controversy:” it is the best way to defend science.

as long as teachers understand the science and its historical context

The role of science in modern societies is complex. Science-based observations and innovations drive a range of economically important, as well as socially disruptive, technologies. A range of opinion polls indicate that the American public “supports” science, while at the same time rejecting rigorously established scientific conclusions on topics ranging from the safety of genetically modified organisms and the role of vaccines in causing autism to the effects of burning fossil fuels on the global environment [Pew: Views on science and society]. Given that a foundational principle of science is that the natural world can be explained without calling on supernatural actors, it remains surprising that a substantial majority of people report that they believe that supernatural entities are involved in human evolution [as reported by the Gallup organization]; although the theistic percentage has been dropping  (a little) of late. This situation highlights the fact that when science intrudes on the personal or the philosophical (within which I include the theological and the  ideological), many people are willing to abandon the discipline of science to embrace explanations based on personal beliefs. These include the existence of a supernatural entity that cares for people, at least enough to create them, and that there are easily identifiable reasons why a child develops autism.

Where science appears to conflict with various non-scientific positions, the public has pushed back and rejected the scientific. This is perhaps best represented by the recent spate of “teach the controversy” legislative efforts, primarily centered on evolutionary theory and the reality of anthropogenic climate change [see Nature: Revamped ‘anti-science’ education bills], although we might expect to see, on more politically correct campuses, similar calls for anti-GMO, anti-vaccination, or gender-based curricula. In the face of the disconnect between scientific and non-scientific (philosophical, ideological, theological) personal views, I would suggest that an important part of the problem has didaskalogenic roots; that is, it arises from the way science is taught – all too often expecting students to memorize terms and master various heuristics (tricks) to answer questions rather than developing a self-critical understanding of ideas, their origins, supporting evidence, limitations, and practice in applying them.

 

Science is a social activity, based on a set of accepted core assumptions; it is not so much concerned with Truth, which could, in fact, be beyond our comprehension, but rather with developing a universal working knowledge, composed of ideas based on empirical observations that expand in their explanatory power over time to allow us to predict and manipulate various phenomena.  Science is a product of society rather than isolated individuals, but only rarely is the interaction between the scientific enterprise and its social context articulated clearly enough so that students and the general public can develop an understanding of how the two interact.  As an example, how many people appreciate the larger implications of the transition from an Earth to a Sun- or galaxy-centered cosmology?  All too often students are taught about this transition without regard to its empirical drivers and philosophical and sociological implications, as if the opponents at the time were benighted religious dummies. Yet, how many students or their teachers appreciate that as originally presented the Copernican system had more hypothetical epicycles and related Rube Goldberg-esque kludges, introduced to make the model accurate, than the competing Ptolemic Sun-centered system? Do students understand how Kepler’s recognition of elliptical orbits eliminated the need for such artifices and set the stage for Newtonian physics?  And how did the expulsion of humanity from the center to the periphery of things influence peoples’ views on humanity’s role and importance?

So how can education adapt to help students and the general public develop a more realistic understanding of how science works?  To my mind, teaching the controversy is a particularly attractive strategy, on the assumption that teachers have a strong grounding in the discipline they are teaching, something that many science degree programs do not achieve, as discussed below. For example, a common attack against evolutionary mechanisms relies on a failure to grasp the power of variation, arising from stochastic processes (mutation), coupled to the power of natural, social, and sexual selection. There is clear evidence that people find stochastic processes difficult to understand and accept [see Garvin-Doxas & Klymkowsky & Fooled by Randomness].  An instructor who is not aware of the educational challenges associated with grasping stochastic processes, including those central to evolutionary change, risks the same hurdles that led pre-molecular biologists to reject natural selection and turn to more “directed” processes, such as orthogenesis [see Bowler: The eclipse of Darwinism & Wikipedia]. Presumably students are even more vulnerable to intelligent-design  creationist arguments centered around probabilities.

The fact that single cell measurements enable us to visualize biologically meaningful stochastic processes makes designing course materials to explicitly introduce such processes easier [Biology education in the light of single cell/molecule studies].  An interesting example is the recent work on visualizing the evolution of antibiotic resistance macroscopically [see The evolution of bacteria on a “mega-plate” petri dish].

To be in a position to “teach the controversy” effectively, it is critical that students understand how science works, specifically its progressive nature, exemplified through the process of generating and testing, and where necessary, rejecting, clearly formulated and predictive hypotheses – a process antithetical to a Creationist (religious) perspective [a good overview is provided here: Using creationism to teach critical thinking].  At the same time, teachers need a working understanding of the disciplinary foundations of their subject, its core observations, and their implications. Unfortunately, many are called upon to teach subjects with which they may have only a passing familiarity.  Moreover, even majors in a subject may emerge with a weak understanding of foundational concepts and their origins – they may be uncomfortable teaching what they have learned.  While there is an implicit assumption that a college curriculum is well designed and effective, there is often little in the way of objective evidence that this is the case. While many of our dedicated teachers (particularly those I have met as part of the CU Teach program) work diligently to address these issues on their own, it is clear that many have not been exposed to a critical examination of the empirical observations and experimental results upon which their discipline is based [see Biology teachers often dismiss evolution & Teachers’ Knowledge Structure, Acceptance & Teaching of Evolution].  Many is the molecular biology department that does not require formal coursework in basic evolutionary mechanisms, much less a thorough consideration of natural, social, and sexual selection, and non-adaptive mechanisms, such as those associated with population bottlenecks and genetic drift, stochastic processes that play a key role in the evolution of many species, including humankind. Similarly, more ecologically- and physiologically-oriented majors are often “afraid” of the molecular foundations of evolutionary processes. As part of an introductory chemistry curriculum redesign project (CLUE), Melanie Cooper and her group at Michigan State University have found that students in conventional courses often fail to grasp key concepts, and that subsequent courses can sometimes fail to remediate the didaskalogenic damage done in earlier courses [see: an Achilles Heel in Chemistry Education].

 

The importance of a historical perspective: The power of scientific explanations are obvious, but they can become abstract when their historical roots are forgotten, or never articulated. A clear example is that the value of vaccination is obvious in the presence of deadly and disfiguring diseases; in their absence (due primarily to wide-spread vaccination), the value of vaccination can be called into question, resulting in the avoidable re-emergence of these diseases.  In this context, it would be important that students understand the dynamics and molecular complexity of biological systems, so that students can explain why it is that all drugs and treatments have potential side-effects, and how each individual’s genetic background influences these side-effects (although in the case of vaccination, such side effects do not include autism).

Often “controversy” arises when scientific explanations have broader social, political, or philosophical implications. Religious objections to evolutionary theory arise primarily, I believe, from the implication that we (humans) are not the result of a plan, created or evolved, but rather that we are accidents of mindless, meaningless, and often gratuitously cruel processes. The idea that our species, which emerged rather recently (that is, a few million years ago) on a minor planet on the edge of an average galaxy, in a universe that popped into existence for no particular reason or purpose ~14 billion years ago, can have disconcerting implications [link]. Moreover, recognizing that a “small” change in the trajectory of an asteroid could change the chance that humanity ever evolved [see: Dinosaur asteroid hit ‘worst possible place’] can be sobering and may well undermine one’s belief in the significance of human existence. How does it impact our social fabric if we are an accident, rather than the intention of a supernatural being or the inevitable product of natural processes?

Yet, as a person who firmly believes in the French motto of liberté, égalité, fraternité, laïcité, I feel fairly certain that no science-based scenario on the origin and evolution of the universe or life, or the implications of sexual dimorphism or racial differences, etc, can challenge the importance of our duty to treat others with respect, to defend their freedoms, and to insure their equality before the law. Which is not to say that conflicts do not inevitably arise between different belief systems – in my own view, patriarchal oppression needs to be called out and actively opposed where ever it occurs, whether in Saudi Arabia or on college campuses (e.g. UC Berkeley or Harvard).

This is not to say that presenting the conflicts between scientific explanations of phenomena, such as race, and non-scientific, but more important beliefs, such as equality under the law, is easy. When considering a number of natural cruelties, Charles Darwin wrote that evolutionary theory would claim that these are “as small consequences of one general law, leading to the advancement of all organic beings, namely, multiply, vary, let the strongest live  and the weakest die” note the absence of any reference to morality, or even sympathy for the “weakest”.  In fact, Darwin would have argued that the apparent, and overt cruelty that is rampant in the “natural” world is evidence that God was forced by the laws of nature to create the world the way it is, presumably a world that is absurdly old and excessively vast. Such arguments echo the view that God had no choice other than whether to create or not; that for all its flaws, evils, and unnecessary suffering this is, as posited by Gottfried Leibniz (1646-1716) and satirized by Voltaire in his novel Candide, the best of all possible worlds. Yet, as a member of a reasonably liberal, and periodically enlightened, society, we see it as our responsibility to ameliorate such evils, to care for the weak, the sick, and the damaged and to improve human existence; to address prejudice and political manipulation [thank you Supreme Court for ruling against race-based redistricting].  Whether anchored by philosophical or religious roots, many of us are driven to reject a scientific (biological) quietism (“a theology and practice of inner prayer that emphasizes a state of extreme passivity”) by actively manipulating our social, political, and physical environment and striving to improve the human condition, in part through science and the technologies it makes possible.

At the same time, introducing social-scientific interactions can be fraught with potential  controversies, particularly in our excessively politicized and self-righteous society. In my own introductory biology class (biofundamentals), we consider potentially contentious issues that include sexual dimorphism and selection and social evolutionary processes and their implications.  As an example, social systems (and we are social animals) are susceptible to social cheating and groups develop defenses against cheaters; how such biological ideas interact with historical, political and ideological perspectives is complex, and certainly beyond the scope of an introductory biology course, but worth acknowledging [PLoS blog link].

In a similar manner, we understand the brain as an evolved cellular system influenced by various experiences, including those that occur during development and subsequent maturation.  Family life interacts with genetic factors in a complex, and often unpredictable way, to shape behaviors.  But it seems unlikely that a free and enlightened society can function if it takes seriously the premise that we lack free-will and so cannot be held responsible for our actions, an idea of some current popularity [see Free will could all be an illusion]. Given the complexity of biological systems, I for one am willing to embrace the idea of constrained free will, no matter what scientific speculations are currently in vogue. Recognizing the complexities of biological systems, including the brain, with their various adaptive responses and feedback systems can be challenging. In this light, I am reminded of the contrast between the Doomsday scenario of Paul Ehrlich’s The Population Bomb, and the data-based view of the late Hans Rosling in Don’t Panic – The Facts About Population.

All of which is to say that we need to see science not as authoritarian, telling us who we are or what we should do, but as a tool to do what we think is best and why it might be difficult to achieve. We need to recognize how scientific observations inform but do not dictate our decisions. We need to embrace the tentative, but strict nature of the scientific enterprise which, while it cannot arrive at “Truth” can certainly identify non-sense.

In an age of rampant narcissism and social cheating – the importance of teaching social evolutionary mechanisms.

As socioeconomic inequality grows,  the publicly acknowledged importance of traits such as honesty, loyalty, self-sacrifice, and reciprocity appears to have fallen out of favor with some of our socio-economic and political elites. How many people condeHutton quotemn a person as dishonest one day and embrace them the next? Dishonesty and selfishness no longer appear to be taboo, or a source of shame that needs to be expurgated (perhaps my Roman Catholic upbringing is bubbling to the surface here).  A disavowal of shame and guilt and the lack of serious social censure appears to be on the rise, particularly within the excessively wealthy and privileged, as if the society from which they extracted their wealth and fame does not deserve their active participation and support [link: Hutton, 2009].  They have embraced a “winning takes all” strategy.

birds in a flockIf an understanding of evolutionary mechanisms is weak within the general population [link], the situation is likely to be much worse when it comes to an understanding of the role and outcomes of social evolutionary mechanisms. Yet, the evolutionary origins of social systems, and the mechanisms by which such systems are maintained against the effects of what are known as “social cheaters”, are critical to understanding and defending, human social behaviors  such as honesty, cooperation, loyalty, self-sacrifice, self-restraint, mutual respect, responsibility and kindness.

While evolutionary processes are often caricatured as favoring selfish behaviors, the facts tell a more complex, organism-specific story [link: Aktipis 2016]. Cooperation between organisms underlies a wide range of behaviors, from sexual reproduction and the formation of multicellular organisms (animals, plants, and people) to social systems, ranging from microbial films to bee colonies and construction companies [see Bourke, 2011: Principles of Social Evolution] [Wikipedia link].

One of the best studied of social systems involves the cellular slime mold Dictyostelium discoideum [Wikipedia link].  When life is good, that is when the world is moist and bacteria, the food of these organisms, are plentiful, D. discoideum live and reproduce happily as single celled amoeba-like individuals in soil.  Given their small size (~5 μm diameter), they cannot travel far, but that does not matter as long as their environment is hospitable.  When the environment turns hostile, however, an important survival strategy is to migrate to a new location – but what is a little guy to do?  The answer in this species is to cooperate.  Individual amoeba begin to secrete a chemical that acts to attract others; eventually thousands of individuals aggregate to form a multicellular “slug”; slugs migrate around to 1066px-Dicty_Life_Cycle_H01.svgfind a hospitable place and then differentiate into a fruiting body that stands ~1mm (20x the size of an individual amoeba) above the ground.  To form the stalk that lifts the “fruiting body” into the air, a subset of cells (once independent individuals) change shape. These stalk cells die, while the rest of the cells form the fruiting body, which consists of spores – cells specialized to survive dehydration.  Spores are released into the air where they float and are dispersed over a wide range.  Those spores that land in a happy place (moist and verdant), revert to the amoeboid life style, eat, grow, divide and generate a new (clonal) population of amoeboid cells: they have escaped from a hostile environment to inhabit a new world, a migration made possible by the sacrifice of the cells that became the stalk (and died in the process).  Similar types of behavior occur in a wide range of macroscopic organisms [Scrambling to the top: link].  Normally, who becomes a stalk cell and who becomes a spore is a stochastic process [see previous PLoS blog post on stochastics and biology education].

Cheaters in the slime mold system are individuals who take part in the aggregation process (they respond to the migration signal and become part of the slug), but have altered their behavior to avoid becoming a stalk cell – no self-sacrifice for them. Instead they become spores.  In the short run, such a strategy can be beneficial to the individual, after all it has a better chance of survival if it can escape a hostile environment.  But imagine a population made up only of cheaters – no self-sacrifice, no stalk, no survival advantage = death [see link: Strassmann & Queller, 2009].

A classic example of social cheating with immediate relevance to the human situation is cancer.  Within a sexually reproducing multicellular organism, reproduction is strictly restricted to the cells of the germ line – eggs and sperm.  The other cells of the organism, known collectively as somatic cells, have ceded their reproductive rights to the organism as a whole.  While somatic cells can divide, they divide in a controlled and strictly regulated (unselfish) way.  Somatic cells do not survive the death of the organism – only germ line cells (sperm and eggs) are able to produce a new organism.  In the end cellular cooperation has been a productive strategy, as witness the number of different types of multicellular organisms, including humans.  If a somatic cell breaks the social contract and cheats, that is, begins to divide (asexually) in an independent manner, it can lead to the formation of a  tumor and later, if the cells of the tumor start to migrate within the organism, to metastatic cancer.  More rarely (apparently) such cells can migrate between organisms, as in the case of transmissible cancers in dogs, Tasmanian Devils, and clams [see links: Murchison 2009 and Ujvari et al 2016).  The growth and evolution of the tumor cell leads to the death of the organism and the cancer cells’ own extinction, another example of the myopic nature of evolutionary processes.

In the case of cancer the organism’s defenses against social cheaters comes in two forms, intrinsic to the individual cheater cells, in the form of cell suicide (known through a number of technical terms including apoptosis, anoikis and necroptosis)[link: Su et al., 2015] and extrinsic and organismic processes, such as the ability of the organism’s immune system to identify and kill cancer cells – a phenomena with therapeutically relevant implications [link: Ledford, 2014].  We can think of these two processes as guilt + shame (leading to cellular suicide) and policing + punishment (leading to immune system killing).  For a cell to escape growth control and to evolve to produce metastatic disease, it needs to inactivate or ignore intrinsic cell death systems and to evade the immune system.

To consider another example, social systems are based on cooperation, often involving the sharing of resources with those in need.  A recent example is the sharing of food (blood) between vampire bats [see link: Carter & Wilkinson, 2013].  The rules, as noted by Aktipis, are simple, 1) ask only when in need and 2) give when asked and able.  In this context, we can identify two types of social cheaters – those who ask when they do not need and those you fail to give when asked and able.  People who refuse to work even when they can and when jobs are available fall into the first group, the rich who avoid taxes and fail to donate significant funds to charities the other.  It is an interesting question of how to characterize those who borrow money and fail to repay it.  Bankruptcy laws that protect the wealth of the borrower while leading to losses to the lender might be seen as acting to undermine the social contract (clearly philosophers’ and economists’ comments here would be relevant).

Given that social systems at all levels are based on potentially costly traits, such as honesty, loyalty, self-sacrifice, and reciprocity, the evolutionary origins of social systems must lie in their ability to increase reproductive success, either directly or through effects on relatives, a phenomena known as inclusive fitness [Wikipedia link]. Evolutionary processes also render social systems vulnerable to cheating and so have driven the development of a range of defenses against various forms of social cheaters (see above).  But recent political and cultural events appear to be acting to erode and/or ignore society’s defenses.

So what to do?  Revolution? From a PLoS Science education perspective, one strategy suggests itself:  to encourage (require) that students and the broader public be introduced to effective instruction on social evolutionary mechanisms, the traits they can generate (various forms of altruism and cooperation), the reality and pernicious effects of social cheaters, and the importance of defenses against them.  In this light, it appears that social evolutionary processes are missing from the Next Generation Science Standards [NGSS link]. Understanding the biology, together with effective courses in civics [see link: Teaching Civics in the Year of The Donald] might serve to bolster the defense of civil society.

Thursday, December 22, 2016 – Mike Klymkowsky

Featured image is used with permission from Matthew Lutz (Princeton University).

Army ants’ ‘living’ bridges span collective intelligence, ‘swarm’ robotics (PNAS)

 

White House honors exceptional student scientists in sixth and final Science Fair

Extraordinary student scientists from across the United States are coming to the White House for the Obama administration’s sixth and final science fair. This year’s cohort of student scientists share creative solutions to some of the world’s greatest challenges, such as 17-year-old Olivia Hallisey’s award-winning Ebola diagnostic test, which doesn’t rely on a cold chain, to nine-year-old Jacob Leggette, whose entrepreneurial spirit connected him with 3D printers, which he has used to manufacture toys and games. Meet all the participants in the White House Science Fair here.

While the student scientists exhibiting their work at the Sixth Annual White House Science Fair span grades K-12 and come from many different backgrounds and hometowns across the U.S., the average student does not have access to the resources and mentorship to make these projects possible. In 2013, the PLOS SciEd Blog took a critical look at top-tier student science fairs and questions whether these competitions recognize talent or privilege. An excerpt from the post is included below:

The room is crowded with row after row of trifold poster boards and judges squinting and taking notes. Among the posters illustrating the effects of soil character on worm health, or the effectiveness of hand sanitizer, I see a project on amino acid substitution due to missense mutations. I’m judging the middle school division, but this project is at the level of a high school or even college student. When it comes time to decide the winners, I battle the other judges who favor complex project topics over soundness of experimental design. The owner of the missense mutation project had access to resources and connections not shared by the students testing soil and hand-sanitizer. There are clearly two project tiers within the competition, and they aren’t separated by scientific understanding, but by access to the professional scientific world. If the mutation project wins over soil character, does it mean we are punishing students who don’t have pre-existing science connections?

Science fairs: rewarding talent or privilege? by Erin Salter.

The White House Science Fair starts at 1pm EST. Watch a live stream on the White House website and follow along on social media at #WHScienceFair!

Photo courtesy of the White House, taken at 2010 Science Fair. October 18, 2010. (Official White House Photo by Pete Souza).