All science educators
face pedagogical difficulties, but when considering the social
ramifications of scientific ideas, few face as great a challenge as
biology teachers. Studies consistently show more than half of Americans
reject any concept of biological evolution (Harris Poll, 2005, Miller et
al., 2006). Students embody just such a cross-section of society. Much
ink has been spilled explaining how best to teach evolution,
particularly to unwilling students (Cavallo and McCall, 2008, Nelson,
2008). In this paper I argue that use of basic, widely recognized case
studies involving human evolution can make a difference. Fortunately,
because people are naturally most curious about themselves, this is easy
and fun to do.
My experience after
twenty years of teaching general and advanced biology courses with an
evolutionary emphasis (including human evolution, evolutionary theory,
vertebrate paleontology, and comparative anatomy) is that acceptance of
biological evolution is not an all-or-nothing proposition. Not only are
most classes a mixed bag in terms of student acceptance of evolutionary
thinking, but even among students who end up accepting the factual
nature of evolution, views are often severely limited or constrained.
Students may agree with the basic notion of biological evolution, but
their understanding may be far from what their instructor has in mind.
In particular, I have found (via the statistical study described in this
study) that students are most willing to accept biological evolution as
1) an historical explanation for 2) physical features of 3) non-human
organisms. In other words, it produced dinosaur bones long ago. In
addition, students often develop 4) teleological, Lamarckian notions.
Most students emerge from my general classes with a thorough, modern
view of evolution, but where some get hung up it is likely to involve
acceptance of evolution as (in contrast to the numbered points above) 1)
an ongoing process that involves 2) non-physical (e.g., biochemical,
physiological, or behavioral) traits, and most of all as a process that
3) affects humans. Students generally accept evolution of peppered
moths. As Allchin (1999) has argued, the “hang-up” typically involves
human evolution. Regarding acceptance of evolutionary science, this is
for most people the final, highest hurdle. Yet as Darwin himself wrote
in his “C” notebook (1838) more than twenty years before the publication
of his landmark On the Origin of Species (1859a), when he was
just beginning to piece together his ideas on natural selection, man “is
no exception” to evolution. Barely a month before the publication of
Origin—in which Darwin hinted at but was unwilling to spell out the
explicit claim of human evolution—he wrote in a letter (1859b) about
evolution that there is “no possible means of drawing [a] line & saying
here you must stop.”
Like Tycho Brahe, the 16th
century Danish astronomer who, after observing planetary motion, aligned
his observations with his prevailing geocentric worldview by positing
that extraterrestrial planets do indeed orbit the sun but the entire
solar system then orbits Earth (Barash, 2007), people often attempt to
confront the concrete empirical evidence for evolution by meeting it
halfway. In essence, they admit it as a powerful explanatory force but
only up to a point, invariably with the proverbial line drawn in the
sand up to but not including human beings, as Darwin implied in the
letter cited above. The result is a partial acceptance: wrong in that it
is not wholly right. As Barash puts it (2007), “Give ground in response
to undeniable facts, but if those facts conflict with your more
cherished beliefs, hold fast to the latter.”
Given the ubiquity of
religious, philosophical, and other social objections to evolution, this
is not surprising. Many people mistakenly believe acceptance of
evolution will shatter their faith or lead to moral nihilism (Brem et
al., 2003). They are wary of strict philosophical naturalism. They find
the idea that humans can be studied as biological creatures—as
animals—alarming, and worry that such investigation degrades and demeans
us. They forget that evolution depends on environmental context, and
thus they fear, wrongly, that genes fully predetermine rather than
predispose. Despite the fact that no legitimate scientific evidence has
been found which contradicts evolution, even with tremendous scrutiny,
and that instead a huge weight of consilient scientific evidence
(multiple independent lines of data) supports the factual nature of
human evolution, these social objections carry the battle for a large
number of people. Given that many young people whose minds are not yet
made up are willing to give fair hearing to objective evidence, it
behooves biology teachers to face these issues squarely, clearly, and
Sadly, educators must
not only confront social dimensions of science but must, in many cases,
undo years of misinformation or neglect. Students must recognize that
evolution is not merely another chapter or section of their textbook: it
is the essential, fundamental, unifying theme of all life science. In
Dobzhansky’s famous words, “Nothing in biology makes sense except in the
light of evolution” (1973). Students must see that although evolutionary
theory remains a field of vigorous debate, its central, factual nature
is not in dispute among scientists. Once students have a clearer grasp
of the nature and scope of science and a better comprehension of what
evolution does and does not entail, instructors must not retreat in the
face of student fears about human evolution. They must confront such
qualms head on.
I recommend that
instructors, especially at the college level where students are more
mature, not shy away from the contentious topic of human evolution,
which is the primary reason people are often unwilling to accept the
possibility of evolution. Such peoples’ “understanding” of evolution is
usually grossly misinformed, but it is typically dependent on bones and
fossils. Further, I contend that when guided by the skilled hand of a
dedicated, well-informed instructor, discussion of human behavior,
including thorny new fields of evolutionary psychology and sociobiology,
will have greater impact than traditional exposition of
paleoanthropology (of which see the excellent review in Alles and
Stevenson, 2003). Not only does exploration of human evolution satisfy
curiosity, but it is likely to dispel myths and misconceptions and
ultimately leave students with a purer, broader understanding of the
thriving, dynamic disciplines comprising modern biology.
Here I provide specific
ideas for human-based teaching of evolutionary concepts. Second, to
demonstrate that such teaching makes a difference, I present results of
extensive student surveys. Third, I offer time-tested suggestions,
gleaned from this study, for teaching evolution (human and otherwise).
Students who flat out refuse to consider the possibility of evolution
may never be persuaded, but then they probably don’t belong in the
classroom in the first place. If students are willing to listen and
engage in open dialogue, my tips offer a high likelihood of success.
Materials and Methods
In terms of pedagogy,
the general Biology 110: Principles of Biology course has been revised
at my institution such that evolution is the first topic and a
consistent, ever-present theme. The course is required for biology
majors and fulfills a basic laboratory science general education
requirement for all students; typically half to two-thirds of enrolled
students are non-majors. Instead of merely describing a history pageant,
I explain evolution as an ongoing process. I present results of
evolutionary studies in many species but dwell especially on humans. In
lieu of bones and fossils I devote more time to behavior, including
complex systems such as language, ethics, and aesthetics. I eschew
delineation of various lines of evidence supporting evolution, which are
readily found in every biology text and many excellent websites, and
focus instead on discussion of what kinds of empirical evidence might
constitute evidence against evolution (which fits better with the
nature and methodology of science). In addition I concentrate on
examples of evolution in everyday life, including human social
evolution, disease, and “Darwinian medicine” (Williams and Ness, 1996;
Burnham and Phelan, 2001; Dawkins, 2004; Cochran and Harpending, 2009).
Case studies are an
effective way of teaching evolutionary concepts (Goldstein, 2008), and
it is absurdly easy to find human-based studies of evolution, which are
available in most modern biology texts and a staple of popular
television documentaries, science magazines, and websites. Here are
fifteen examples of case studies I have found effective, whose use I
Metabolic-based cases, such as why humans (unlike most
mammals and some other primates) cannot synthesize Vitamin C and must
therefore ingest it, due to mutation in the now inactive human GULO
pseudogene, make fascinating stories. Another simple case involves
lactose tolerance, which is the exception rather than the rule, and how
it may have evolved in populations in concert with domestication of
livestock. Population differences in alcohol dehydrogenase enzyme
is another student favorite.
Everyone knows of the sickle cell anemia vs. malaria trade-off,
but recently proposed hypotheses suggest similar stabilizing
compromises such as cystic fibrosis vs. tuberculosis,
hemochromatosis vs. bubonic plague, and even high blood sugar levels
(leading to diabetes) vs. hypothermia in people, including ancestral
Europeans, living at very high latitudes. Such cases offer speculative
evolutionary explanations for the persistence of debilitating genetic
conditions (Moalem and Prince, 2007).
Adaptation to altitude and climate is a core anthropology
topic and thus widely available. Although skin color, folic acid, and
Vitamin D make an intriguing story of natural selection (sunlight is
needed to create Vitamin D, yet destroys stores of folate), teachers are
cautioned not to raise the issue of skin color unless they are prepared
to devote much attention to it. Students like to discuss racial
concerns (especially genetic variation and IQ) yet these often yield
more disadvantages than benefits in class. The Vitamin D story is
compelling (Jablonski, 2004). Moalem and Prince (2007) point to seasonal
variation in cholesterol levels as well as overall high levels of
cholesterol (a precursor of Vitamin D synthesis) in some populations, as
another evolutionary tradeoff.
Quirky physiological responses and reflexes, such as the
photic sneeze reflex (sneezing after exposure to bright light,
especially after emerging from darkness), which some claim offered a
benefit to clearing upper respiratory passages from potential pathogens
encountered by ancestors in musty caves, offer fun opportunities to
discuss human physiology as well as prospective dangers of eager
over-reliance on evolutionary “just-so stories.”
Evolution of resistance in pathogenic organisms (such as
bacteria responsible for tuberculosis, or mosquitoes and DDT) to
antibiotics and other compounds is a widely-known topic, so students are
likely to have heard of it, but often they have basic facts and
principles confused, and may not appreciate connections to humans (Levy,
Host manipulation by parasites and other pathogens offers
an intriguing evolutionary perspective on disease. Paul Ewald (1994) has
generated provocative ideas about, for example, why colds are less
virulent than other pathogens (so we remain mobile and spread the
rhinovirus), whereas pathogens transmitted by non-human vectors (e.g.,
mosquito-spread malaria-causing Plasomodium) keep us in one
place, where vectors can find us. Ewald suggests we can influence
pathogen evolution toward less virulence , e.g., “selecting” for less
virulent cholera by cleaning up water supplies and ensuring infected
people don’t contaminate them, forcing cholera to become less harmful in
order to spread.
Predisposition to cancer or heart disease, or other genetic
bases of disease, are widely discussed in the popular press and
hence easy to find and familiar to students. College-age men and women
may feel invulnerable, but they will be interested as elder family
members manifest health concerns.
Imperfections are everywhere in the natural world;
students are sure to know of many in the human body, including various
adaptive compromises: pelvis adapted for upright stance and
bipedal locomotion yet poor for childbirth; spine from quadrupedal
ancestors, leading to back problems; lowered larynx allowing for
vocalization yet letting us choke on food. There are also numerous
vestigial features, including but not limited to the vermiform
appendix, coccyx, wisdom teeth, extrinsic ear muscles, “goosebumps” to
fluff fur for insulation, and nipples and rudimentary uterus of males.
Shubin (2008) is a great source for such examples involving the human
body, as is Chapter One of Darwin’s The Descent of Man (1871).
Students enjoy pondering the role of genes and basic
human behavior, such as thrill-seeking behavior or assertiveness, or
autism and schizophrenia (Holden, 2009). But make sure students are
aware of epigenetic and environmental effects (e.g., from studies of
identical twins, and from behavioral changes with age, and so on).
However, students find the rapidly emerging fields of sociobiology
and evolutionary psychology, which present broader behavioral
implications, controversial and inflammatory. These topics may shed more
heat than light, but create a smoldering spark that can lead students to
see human behavior in evolutionary terms. Two popular areas are human
mating strategies and altruism/evolutionary ethics (Allchin,
A current hot topic is the role of methylation in epigenetic
imprinting of genes. For example, some biologists argue (Jirtle and
Skinner, 2007; nice review in Moalem and Prince, 2007) that the current
rise in obesity stems from a “thrifty” gene which helped ancestral
humans survive lean times, yet now leads to overweight people in
cultures where low-nutrition, high-calorie food is abundant. Similar
stories implicate smoking in health woes of children and even
grandchildren via methylation of the fetal genome. Students enjoy
discussing the extent to which their physiology and health are due, or
not, to their own lifestyle choices. Study of epigenetic changes
suggests something akin to “on-demand” mutations, which should lead to
discussion of Lamarck vs. Darwin and inheritance of acquired variation.
Non-coding “junk” DNA and transposons (“jumping genes,” which may
have a higher incidence in African primates, including humans) can lead
to all sorts of novel variations. High levels of HERVs (human endogenous
retroviruses) in the human genome might have provided our ancestors with
increased fodder for phenotypic variation, and thus might have been
critical in human evolution. This also ties in to concepts of
coevolution, such as the origin of eukaryotic organelles via
The topic of aging, and why humans live so long (and with what
social costs and benefits) is, to young people, a fascinating but
non-threatening way to study evolution.
The Human Genome Project offers many opportunities to discuss
genetic variation (e.g., haplotype mapping) within and between
populations and species, as well as the relationship between genetics
and health, and the growing possibility of tailored pharmacogenomic
Gene and stem cell therapy and the specter of genetic manipulation
or “enhancement” in humans is guaranteed to provoke discussion, much of
it invariably veering off topic, but one can steer the dialogue toward
the human evolutionary past, present, and future.
Suffice to say one could
fill a book listing examples of human-based evolution studies. As time
permits (or as supplementary readings and fodder for discussion) I
recommend use of these and countless other “anthropocentric” studies.
Any biology topic is best viewed through an evolutionary lens.
For ten years (1994-2003
inclusive) I utilized a 25 question anonymous, pre- and post-semester
survey to gauge student attitudes about evolution (Werth, 2009), as well
as to provide feedback for outcomes assessment and thereby improve
teaching in this Principles of Biology course. Results presented here
derive from a spin-off of this study, with a shorter, modified
questionnaire used for three years (2000-2003) in this course as well as
to freshmen and sophomores in a basic Organismal Biology course
(primarily plant and animal structure and function), including six
cohorts of students (total N=166). [The survey was also attempted in two
sections of a human evolution class, but results of such administration
are not presented here, as the sample size was small and the
self-selected students who enrolled in that course all began highly
accepting of evolutionary principles.] Each class was surveyed at the
start of the semester (on or around the second day of classes, after the
roster had stabilized) and again, using the same questionnaire, during
the final class of the semester. Although this longitudinal study
followed each student cohort, no attempt was made to track changes in
responses of individual students, as all responses were anonymous. No
credit was given for this survey; participation was optional, but
students were told it was part of a pedagogical study and urged to
The survey involved 12
statements to which students were asked to respond using a simple
seven-point Likert scale of agreement or disagreement (1=agree
completely; 4=unsure or don’t know; 7=disagree completely). The five
statements most relevant to the study presented here are:
Evolution is a purely historical phenomenon
(i.e., all in the past).
- Evolution applies
only to non-human species.
- Evolution applies
only to physical features, like bones.
- Evolution does not
affect complex behavioral systems such as ethics.
- Evolution works
toward a purpose or goal.
The wording of these
non-normative statements did not change over the three years of the
study. Statements were counterfactual; objective, empirical evidence
strongly supports rejection rather than acceptance in all cases.
Presuming an effective pedagogical approach, students who initially
accept such claims should move toward rejection over the course of the
semester. In other words, the null hypothesis is that scoring on the
seven-point scale should increase. Note that one of the five statements
(#2) deals specifically with evolution of our species, but the
expectation is that by teaching human-based evolution students will
better understand multiple integrated core concepts of evolutionary
theory, not merely human evolution. Also note that instead of harping
explicitly on the five points embodied by these statements, my teaching
via case studies addressed them indirectly rather than directly.
In addition to this
formal survey, I rely on data from an assessment instrument used by my
department for all sections of our Principles of Biology course, which
involves a brief (approximately twenty minute) “exit interview” with
individual students at the conclusion of the course to assess how well
we are teaching basic concepts. Although this session is not required, I
explain its value as a review session before the final examination, and
hence have excellent (~85%) participation. The interview involves five
questions, all scored by the instructor on a four point scale to assess
student mastery of the material, and in this way I gain even more
quantitative and qualitative feedback from my teaching regarding the
effectiveness of my emphasis on human evolution.
The Principles of
Biology textbook for this 2000-2003 study was Discover Biology by
Cain, Damman, Lue and Yoon (Sinauer/Norton 2000, first edition, and in
the third year the second edition, published 2002), and for the Biology
202 Organismal Biology course the text was Life: The Science of
Biology (6e), by Purves, Sadava, Orians and Heller (Sinauer/Freeman
Responses to the five
statements, indicated as percentage of students (data from all classes
combined; N=166 students) responding in each category (1-7), are shown
in Figures 1-5. In general, a majority of students accepted each of the
five statements at the start of the semester yet rejected them at the
end. The total percentage of students agreeing with each statement (from
“agree completely” [response 1] to “agree somewhat”  and “agree a
little” ), as opposed to the percentage of students disagreeing with
each statement (from “disagree a little” [response 5] to “disagree
somewhat”  and “disagree completely” ) are displayed in Table 1
(all years combined). Since percentages in Table 1 exclude response 4
(unsure/don’t know), they do not total 100%. Notably, whereas a majority
of students agreed with all five statements at the outset of the course,
only one quarter to one third of them agreed at the end (summarized in
Table 1. Results of
anonymous survey (2000-2003) on student attitudes toward evolution.
Statement# Percentage agreeing/disagreeing
Evolution is a purely historical phenomenon (i.e., all in the past).
25 → 9 / 84
Evolution applies only to non-human species.
52 / 32
→ 20 / 71
Evolution applies only to physical features, like bones.
53 / 28
→ 27 / 61
Evolution does not affect complex behavioral systems such as ethics.
50 / 30
→ 40 / 44
Evolution works toward a purpose or goal.
52 / 33
→ 41 / 48
The biggest change
engendered by the shift to a clear evolutionary focus with an emphasis
on human evolution concerns the historical versus current nature of
evolutionary change (Figure 1).
At the start of the
semester, nearly two-thirds of students (64%) agreed that evolution is a
thing of the past; at the end, only 9% agreed with this claim and 84%
disagreed with it. Likewise there was a significant, substantial shift
with regard to whether evolution applies only to non-human species or
affects humans as well (Figure 2), as disagreement (at all levels) with
this statement jumped from fewer than a third of students to over 70% of
Figure 1. A concerted pedagogical focus on human
evolution led students to see evolution as an ongoing process. This and
all figures are from an anonymous four-year classroom survey (2000-2003,
results from all years pooled), with error bars representing one
Figure 2. Results show students in the study
became more likely to accept evolution of humans.
Figure 3. Students became more likely to accept
non-physical (e.g., biochemical) evolution.
Figure 4. Students also became more accepting of
evolution of complex behaviors, but less so.
As Figure 3 shows,
slightly fewer students ended up rejecting the claim (#3) that evolution
applies only to physical features. Fewer still changed their minds about
the likelihood of involvement of evolution in complex behavioral systems
(Figure 4), although admittedly this topic was dwelled upon to a lesser
degree in class and not dealt with in the text or other course
materials. Unlike Statements 1 & 2, both 3 & 4 had a sizable number of
students choosing “don’t know/unsure” even at the end of the course,
although less so than at the beginning.
Figure 5. Students were more equivocal about
teleological versus mechanistic explanations of evolution. Responses
show opinions shifted, though not as strongly as with other statements.
As for Statement 5,
which asserts that evolution works toward a goal, there was as in all
cases described here a clear shift in opinion, yet a smaller shift. At
the end of the semester 33% of students still agree with the claim that
evolution is purposeful, although 17% agree only a little, and 29%
disagreed completely at the end of the course.
findings yield similar results as gauged by student responses to
classroom questions and comments in discussions, by responses to
questions on exams and quizzes (particularly essay or short written
answers), and from the end-of-semester oral quizzes and other dialogue
Not all students ended
up rejecting these claims as a result of their enrollment, but whereas a
majority of students accepted them at the start, most students’ views on
evolution shifted dramatically. A general finding is that student
attitudes vary widely. Initially, many accept evolutionary explanations
yet the big “hang-up” clearly appears to be admitting evolution of
humans, especially human behavior. In addition to the five points
specifically addressed in this paper, other attitudes changed as well.
For example, even at the beginning of the course students were much more
willing to accept adaptation within species (i.e., “microevolution”)
than they were speciation or even adaptive radiation (i.e., “macro-” and
“megaevolution” involving appearance of new species), but this too
changed during the course.
How can I be sure that
the changes I found in student attitudes result from my new pedagogical
focus, specifically my increased case study-based emphasis on human
evolution? Most of all, I can compare results with those from my broader
unpublished study (Werth, 2009), which followed students in the same
course over a ten year period, the first half of which preceded my shift
to an evolutionary focus. Results of similar teacher surveys have been
published by Osif (1997), Rutledge and Mitchell (2002), Rutledge and
Warden (2000), and Lovely and Kondrick (2008). My data indicate that a
broadly-based general biology course is likely to change student
attitudes toward evolution, but much more so if evolution is made a
central, unifying theme of the course, and if the dynamic nature of
human evolution is made a center point (Linhart, 1997).
One of the most basic
precepts of evolution is that it is an ongoing process—that it is
insufficient merely to claim that all organisms have evolved, since all
species are still evolving and moreover doing so in relation to one
another in an intricate coevolutionary dance. Results (Figure 1)
indicate that at the end of the course students clearly understand this
concept. Even if evolution were a purely historical phenomenon it would
of course still be amenable to scientific study by the
hypothetical-deductive method (Cooper, 2002, 2004). The fact that humans
are biological creatures and as such exempt neither from laws of nature
nor the process of evolution was likewise grasped by most students. Yes,
we are unique—indeed, all species are unique, otherwise they would
obviously not be distinct species. Still, we recognize that in many
ways, most notably cognitively and culturally, humans stand apart from
other species, yet this does not diminish us. In contrast, the fact that
we are related to all other living things yet have made great strides on
our own might be seen both to ennoble and elevate us.
My results, both
quantitative and qualitative, indicate that although a majority of
students ultimately accept the evolution of behavioral traits and the
non-teleological nature of evolution, they are more conflicted about
these concepts, with fewer students changing their views or more
adopting an uncertain one. Our teleological nature is indeed
deep-seated. As Richard Dawkins (1995) notes, humans have “purpose on
the brain.” Michael Shermer explains (2006) that we see design
everywhere because nature has in fact been designed, yet from a
bottom-up rather than top-down process. He advises that we should “quit
tiptoeing around” and admit that forms follow function “because
evolutionary design is based on functional adaptation.” In my experience
our default anthropocentric, teleological worldview is firmly entrenched
and very difficult to modify. As for the role of genes underlying
evolutionary change, students may counter that genes are mere molecules.
As Colin Tudge (2000) points out for those who deny the influence of
genes, why else do dogs behave like dogs and birds like birds? Of course
genes influence behavior, and since evolution is change in gene
frequency, behavior evolves. Still, teachers must explain the role of
genetic drift and evolutionary byproducts. Every facet of an organism
(including behaviors) need not be adaptive. Instructors will rightly
complain that their schedule is already stretched so thin, especially in
a general biology course, that there is little “flex” time in which to
introduce new material. However, human-based case studies need not
occupy an entire class to make evolution more relevant and meaningful.
They can be inserted as brief examples into lectures or discussions,
using examples I have provided here.
Conclusions and Recommendations
Ironically, much of the
difficulty in teaching human evolution stems from the fact that humans
are naturally predisposed to think in teleological terms (Shermer, 2006;
Kelemen and Rosset, 2009). Design that evolved in nature in a bottom-up
sense, rather than divine design (imposed in a top-down way; Dennett,
1995), is thus a counterintuitive view that often meets resistance. As
E.O. Wilson explains in Consilience (1998), the human mind “did
not evolve to believe in biology.” Darwin himself saw that the deck was
stacked against him. As he wrote in The Descent of Man (1871), “A
belief in all-pervading spiritual agencies seems to be universal.”
Nonetheless it is paramount to explain that acceptance of evolution does
not equal rejection of religious beliefs. It is essential to explain
that scientific and spiritual ideas need not conflict, and that science
does not address supernatural claims (Meadows et al., 2000).
Throughout this paper I
do not refer to “belief” in evolution but rather acceptance of empirical
statements. As Shermer (2006) writes, “evolution is not a religious
tenet, to which one swears allegiance or belief as a matter of faith.”
Evolution is an idea, not an ideology, which is why biologists often
advocate rejection of the term “Darwinism” (Scott and Branch 2009).
Religious objectors may not change their minds easily, if at all, but my
aim is to reach undecided fence-sitters who are willing to listen and
make up their own minds. Maturing college students generally fall into
this camp. Many older adults are unswayable, yet a good number of
students are grappling with new ideas and willing to see the world from
a fresh perspective. As noted earlier, those who enter college resisting
evolutionary teachings often have been misinformed and possess a skewed
view of science. Patient, polite, and non-confrontational,
non-threatening instructors who are nonetheless clear and firm in their
teaching likely bear the best chance of successfully leading students to
view evidence objectively. It would be interesting to monitor student
attitudes years later, to see if seeds planted in the mind bear fruit
years later. Yes, it is true that some reluctant students will not
accept evolution no matter what tack teachers take nor how hard they
try, but in other cases students will accept a balanced, realistic view
of evolution if their concerns are addressed squarely, surely, and
sincerely, as a central pedagogical focus on human evolution does.
It is essential to
maintain a proper attitude. The approach should always be firm but never
confrontational or condescending. The goal is to open minds, not to
close them off. As noted above, most classes include a great diversity
of views on evolution. I have found that many students who resist
evolutionary thinking remain silent and keep concerns to themselves. Not
only do they fear their beliefs are threatened, but they do not want to
expose themselves to potential criticism from classmates or, worse,
instructors. The teacher’s tone is paramount in allaying fears and
reminding students that there is a place for all beliefs, but that
science class is a place to discuss scientific explanations. Never
belittle or blame students for not immediately accepting evolution. In
addition to demeanor, the language one employs is of utmost importance.
The terminology used to present, explain, or even ask questions about
evolution makes a huge difference. Myths and misconceptions persist even
among students who acknowledge evolution from what they have heard or
been mistaught (McComas, 1997). There remains in the minds of college
students much confusion about whether evolution is merely one of many
equally valid views or if it is scientific “truth.” Just as genes are
“linked” on chromosomes, views on evolution are often linked to each
other as well as, more obviously, to religious faith and views on the
compatibility of science and religion.
Finally, as a result of
my survey of student attitudes and experience focusing on human case
studies as a means of teaching evolution, I can offer a few additional
words of guidance for teachers. It is imperative that students
understand the nature and scope of science (Alles, 2001; Farber, 2003).
The easiest way for them to understand what evolution is all about is to
be assured of what it is not about. Students often erroneously equate
“Social Darwinism” with Darwinian evolution. Also, teachers must stay
current with evolutionary explanations. The field has changed greatly in
the past two decades, especially with a proliferation of books on
evolutionary ethics, evolutionary psychology, and sociobiology (Allchin,
1999), and with new ideas in molecular and evolutionary developmental (“evo-devo”)
biology, and hence the possibility of major morphological “leaps” via
minor mutations in regulatory genes. As Kirschner and Gerhart (2005)
note, the origin of novel structures need not involve “irreducible
complexity,” as critics of evolution frequently assert. Explanation of
epigenetic in addition to genetic inheritance is also essential (Jirtle
and Skinner, 2007). I recommend that instructors correct fallacious
ideas (e.g., we did not evolve from monkeys or chimpanzees) yet not get
bogged down in discussion of the origin of life and chemical evolution.
Point out that Darwin was a proponent of hypothesis-based science. Long
before hominid fossils were discovered in Africa he claimed it as the
likely site of human origins: a testable, falsifiable hypothesis.
Evolutionary biology has
changed profoundly in the century and a half since Darwin published
On the Origin of Species (1859), but his approach remains relevant.
He saw that rejection of evolution largely stems from its implications
for humans (hence his follow-up work, 1871’s The Descent of Man),
and he recognized that scientists must not stray from science. In his
words (Darwin 1880), “Freedom of thought is best promoted by the gradual
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