Over 5 million students and 28,000 schools are consistently marginalized or left out of statistics that describe evolution and science education. Although they are relatively few in number compared with their public school counterparts, the millions of students and hundreds of thousands of teachers in private schools need to be counted in research about teaching and learning in the biology classroom. Assumptions have been made about how teachers in these often religious schools teach evolution, but do we have verifiable data? Could teachers in these schools be similar to those in public schools in their teaching of evolution, or is there a silent undercurrent that has not been detected? It is the purpose of this study to reveal more about this underrepresented segment of the population of science teachers.
Studies on the teaching of evolution and the influences on it have been growing in number over the past three decades. They are often conducted in and focused on a particular American state (Ellis, 1986; Zimmerman, 1987; Tatina, 1989; Van Koevering & Stiehl, 1989; Shankar & Skoog, 1993; Osif, 1997; Aguillard, 1999; Weld & McNew, 1999; Benen, 2001; Moore, 2002; Rutledge & Mitchell, 2002; Moore & Kramer, 2005; Donnelly & Boone, 2007). Each includes some form of survey, from very short forms of six questions (Benen, 2001; Rutledge & Mitchell, 2002) to more extensive projects where the statistics of teachers' beliefs were analyzed against what teachers actually taught (Aguillard, 1999; Benen, 2001; Bilica, 2001; Moore & Kraemer, 2005). The present study takes similar aim and looks at teachers' emphasis on evolution in the parochial high school in addition to the factors that influence their teaching.
Rather than focusing on one state, I examined the extent to which evolution is taught in high school biology classrooms in Lutheran schools across the United States. The following questions, which previous studies have answered with regard to teachers in specific states, have now been applied to teachers across the country who teach in this parochial school setting.
1. To what degree do Lutheran secondary school teachers incorporate evolution in their teaching of basic first-year biology courses?
2. How do Lutheran biology teachers compare to public school teachers in their overall emphasis of evolution education in their classroom and the influences that guide their decisions?
The four-part Teaching Evolutionary Topics Survey (TETS; Bilica, 2001) was used to collect data from teachers. The first part surveyed teachers' emphasis in class of the seven fundamental topics of evolution. Bilica (2001) assembled and validated these and created the following evolutionary topic scales: Speciation, Diversity, Descent with Modification, Evidence for Evolution, Natural Selection, Pace and Rate of Evolutionary Change, and Human Evolution. These scales were adapted from the National Science Education Standards (National Research Council, 1996) and Project 2061 (American Association for the Advancement of Science, 1990, 1993). Each teacher in the sample responded to statements on the survey using a Likert scale to rate their emphasis from 1 to 5. The prompts for each emphasis were as follows: 1 == no emphasis —— I do not emphasize this concept at all; 2 == little emphasis —— I may mention this concept briefly or informally during the course; 3 == some emphasis —— I emphasize this concept in one lesson during the course; 4 == moderate emphasis —— I emphasize this concept in more than one lesson during the course; and 5 == strong emphasis —— I emphasize this concept throughout the course.
The second section in the TETS deals with factors that influence teachers' decisions regarding coverage of evolutionary topics. In this 25-question section, teachers responded to statements using Likert-scale responses of ““strongly disagree,”” ““disagree,”” ““undecided//don't know,”” ““agree,”” and ““strongly agree.”” Questions were grouped into categories that spoke to academic preparation and knowledge; students' interest and capacity to learn; teachers' beliefs about evolution; controversy associated with teaching evolution and avoiding topics; support from administrators; parental support for teaching; reliance on textbooks for information; and substituting course material. This section is useful in looking at teachers' reasoning for choosing what and how much they teach about evolution.
The survey included a demographic information section and an optional comments section where teachers could make any statements they deemed necessary. These data were collected to show the extent to which evolution education happens in Lutheran secondary schools.
This survey was mailed to 100%% of the Lutheran high school biology teachers (n == 128) in the United States. School addresses and teachers' names were compiled from Valparaiso University's Directory of Lutheran High Schools (http://www.valpo.edu/churchrelations/lhsdir/) and The Lutheran Annual (Lutheran Church Missouri Synod, 2003). This intended population represents the entirety of Lutheran high school teachers in the United States. These schools are affiliated with the Lutheran Church Missouri Synod (LCMS), the Evangelical Lutheran Church in America (ELCA), the Wisconsin Evangelical Lutheran Synod (WELS), and other independent Lutheran churches.
The surveys were sent in the first week of October 2003 and were personally addressed to each biology teacher where a name was furnished by the Directory of Lutheran High Schools, by the homepage of the school, or through contacting the school office by phone. The target return date was 31 October 2003. Each teacher had been made aware of the survey's coming arrival through either a phone message or an e-mail message from the researcher within 2 weeks of receipt of the survey. A follow-up postcard was mailed to each teacher three weeks after the surveys were mailed. There was no incentive offered for completion and return of the surveys. The total number of returned surveys that were completed in full was 76, or 59%% of the surveyed population. It is from these returned surveys that the data, results, and conclusions have been formed.
The raw data on teaching emphasis on the seven fundamental concepts of evolution showed that all teachers who participated in the study teach some concepts of evolution in their classrooms. The raw data indicate that not all teachers teach on every one of the seven topics of evolution as delineated by Bilica's (2001) survey, but teachers mention and/or teach one or more of the topics during their instructional time in the school year. This is similar to the finding of Berkman et al.'s (2008) national study that 98%% of biology teachers talk about evolution to some degree in class. This is a higher percentage than reported by Moore and Kraemer (2005) in Minnesota (88%% of teachers covering at least some part of evolution), Zimmerman (1987) in Ohio (88%%), and Ellis (1986) in Kentucky (91%%). It is also higher than the 73%% found in South Dakota by Tatina (1989), but the definition of ““teaching about evolution”” in that study focused on longer periods spent teaching about evolution without referring to brief discussions.
I found that the responding teachers placed varying amounts of emphasis on the seven fundamental concepts of evolution (Table 1). Seventy-five percent of Lutheran teachers in the survey speak about speciation in one lesson or more, whereas 84.2%% of them speak about the concept of diversity and 81.6%% about natural selection. Evidence for evolution is emphasized in one lesson or more by 59.2%% of teachers, and the pace and rate of evolution are emphasized by 51.2%%. Descent with modification (44.7%%) and human evolution (30.2%%) are the least-emphasized concepts taught in one lesson or more. These findings are similar to those of Aguillard (1999) and Shankar and Skoog (1993) on human evolution, in which 69%% spent less than 30 minutes on the topic, although 28.3%% of the Lutheran school teachers surveyed spend more than one class period on evidence for evolution, compared with the 17%% reported by Aguillard. In comparing the current study with that of Bilica (2001), the findings for the amount of emphasis on evolutionary topics are quite similar. Rutledge and Mitchell (2002) found that 43%% of teachers avoid teaching about evolution or take a cursory look at it in class. However, a more recent national study of public high school biology teachers found that nationally, 83%% of teachers teach about human evolution in their classes, although the number of hours spent doing so varies (Berkman et al., 2008).
Natural Selection, Diversity of Organisms, and Speciation are emphasized at a higher frequency than Evidence for Evolution, Pace and Rate of Evolution, Descent with Modification, and Human Evolution (Table 1). The greater emphasis on diversity and natural selection could possibly be attributed to the lack of controversy over those topics because of the abundant living examples in nature and the seeming lack of an alternative examination of the topics in the Bible. However, only 31.6%% of the respondents agreed with the statement ““I do not teach some concepts, such as human evolution, because they are too controversial,”” while 61.8%% disagreed. Thus, controversy may not play a great role, although the teachers responded with a high rate of agreement (92.1%%) to the statement ““Evolution is a controversial concept for many people.””
Why certain topics in evolution are not covered as well as others might be better explained by the teachers' responses to questions regarding their beliefs about evolution and science. A slight majority (59.2%%) disagreed with the statement ““Evolutionary topics are supported by scientific evidence.”” More teachers disagreed with ““Evolution is a central and unifying theme in biology”” (75.0%%) and ““Evolution answers many questions about the natural world”” (71.0%%). By contrast, the following studies found that majorities of public school biology teachers agreed that evolution is a central unifying theme: Aguillard (1999; 66%%), Bilica (2001; 65.7%%), Donnelly & Boone (2007; 64%%), and Weld & McNew (1999; 57%%).
Regarding explanation of the world around us, Bilica (2001) found that only 22.8%% of teachers agreed that there are better theories than that of evolution. Shankar and Skoog (1993) found that even fewer teachers (7%%) agreed that other theories explain the natural world better than evolutionary theory. In the present study, a full 75%% of the teachers agreed that ““There are theories other than evolution that better explain the natural world.”” These beliefs within the study group show a great contrast with the public schools.
We can also see in some example comments in the free-response section the reasoning behind the way that teachers in Lutheran high school biology classes choose to emphasize evolution. Of the 53 teachers who responded, 38 indicated that they believe that students need to know about evolution because it is an issue in society. One teacher wrote,
I strongly believe that everyone should be educated about evolution. Many people have such an issue with evolution because they are not educated about it. By presenting the information to the students, they can then make their own educated decisions.
Such comments are typically expanded upon with statements that talk about comparing the Christian worldview with secular worldviews. One teacher wrote, ““We discuss the difference between science and religion. We discuss the difference between an evolutionary worldview and a Christian worldview.”” Another explained it in this way:
They [students] need to know as much or more than the average student. I teach them that evolutionary theory is the best explanation humans —— using their reason —— can put forth. It is logical, scientific, and as supported as any theory in any field. The difference is that Christians view the world as created by God. Evolutionary theory is the explanation that works if no faith in God is present.
The free comments also corroborate the survey finding that 75%% of the teachers believe that ““There are theories other than evolution that better explain the natural world.”” Forty-two of the 53 teachers commented that they taught about evolution but did not believe in it. They often made statements regarding how Christian faith plays into the discussion of evolution and creation. For example, one teacher wrote,
Although time is spent at this school teaching evolutionary explanations and origins, this is done in view of 1 Peter 3:15——16. ““Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect.””
Following a similar line of thought, another teacher wrote,
With regard to the teaching of evolution, I feel it is important as Christians, within our faith, to deal with the facts of evolution. Certainly change on our planet, physically and biologically, has occurred and we cannot deny its ““evolution.”” To do so would be ignorant and unreasonable. To the extent that the ““facts”” should lead anyone to conclude that the earth and everything in it has appeared solely because of ““evolution,”” I would contend that that is a belief based solely on ““faith”” as well. If we are to prepare students to be faithful and wise stewards of our world, it is important for them to distinguish between what happened and what may have happened; what science is and does and what faith is and does.
There is also disagreement between public school teachers and Lutheran school teachers about whether students are capable of understanding evolution. A majority of the teachers I surveyed (79.0%%) disagreed with the statement ““Evolution is too complex for beginning biology students,”” which fits with the smaller majority response (65.8%%) that agreed with the inverse statement ““All students are capable of understanding evolution.”” Although these percentages are close to Bilica's (2001) finding that 67%% of teachers agreed with the statement, they differ greatly from Aguillard's (1999) finding that 30%% of teachers agreed that all students are capable of understanding evolution.
The parental community's influence may also play a part in how teachers approach the teaching of evolution. A simple majority of teachers (44.7%%) didn't know or were undecided in responding to the prompt ““The parents at my school agree that students should learn about evolution.”” Only 34.2%% of the teachers agreed, but only 21.1%% disagreed. A small majority of teachers (65.8%%) disagreed with the statement ““I have felt pressure from the parents in my community to avoid teaching some evolution concepts,”” while 21.1%% agreed with the statement. This level of agreement is also what Van Koevering and Stiehl (1989) found in Wisconsin, whereas Tatina (1989) in South Dakota and Zimmerman (1987) in Ohio found less than 12%% agreement.
From the survey results, we can see that the Lutheran school biology teachers hold some of the same opinions as public school teachers with regard to their emphasis of evolution in the classroom, while the influences that guide their decisions are different. There are teachers who believe that evolution is an important component of a good biological education. There are teachers who feel that evolution is too controversial to speak much about it, and there are teachers who would rather emphasize only parts of the concepts of evolution rather than the whole theory. These same sentiments were found in previous studies on public school teachers in various states.
When considering research on the teaching of evolution in private schools —— and especially those of religious affiliation —— one must also consider the limitations that particular denominations or groups put upon teaching of the topic. Any religious school could have doctrinal issues that affect the approach to teaching evolution. My survey did not ask directly about church doctrines, but half the teachers (50%%) agreed that their principal supports teaching about evolutionary topics, while 30.3%% of them were undecided or didn't know. Because these schools do not have to follow state standards as rigidly as public schools (though it is most likely in their best interest to align themselves within those standards), the teachers will have a bit more freedom in their choices of curriculum. Because of these factors, the present study cannot be universally applied to all private and parochial schools.
All the Lutheran secondary school teachers who responded to my survey teach about evolution in their classrooms, although the amount of teaching is not consistent between teachers. Mass coordination of science lessons is not a possibility among this sample of teachers because of differences in location and local authority and the lack of a venue. These teachers are located throughout the United States and are influenced by local authority and custom. Consistency with other Lutheran biology teachers would not be as much a concern as consistency with local public biology educators. This lack of coordination could change through nationally adopted standards.
It is important to understand that the group of teachers surveyed are a subset of all biology teachers in Lutheran schools across the United States. The rate of return (59%%) was higher than expected for a mailed survey, according to Kirk's (1995) assessment that a mailed survey will typically have a return rate between 10%% and 45%%. Because of the sample size, the results are limited in their application and cannot be extrapolated to represent all Lutheran teachers or the greater private sector of teachers. Future research can take the present study as a starting point for more research within these groups.
Continued study of the non-public sector will be useful. Study of religious-based schools will help bring to light the conflicts and misconceptions regarding science and religion. The Lutheran Church Missouri Synod (which holds the majority of the schools studied here) has the highest number of private high schools after the Catholic Church. It would be useful to survey teachers in Catholic schools because of the size of the population and the influence of the denomination. This should be in addition to studying the thousands of other private schools and their pedagogy.
The results presented here should be of interest to all biology educators. Public and private schools are not at odds with each other in trying to educate the next generation. It appears that teachers in both public and private schools hold some similar opinions about teaching evolution, even if their reasons for doing so are different. As an association of biology teachers, we in the NABT must work toward common understanding so that the richness of knowledge of the biological world can be given to the next generation.