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The acceptance rate of the theory of evolution of subjects in this study was not significantly different from the subjects in previous studies. While no researchers have previously examined freshman biology majors in conjunction with senior biology majors, there still are worthwhile comparisons to be made. For these comparisons, I categorized the answers from question 15 into either Evolutionary Views or Creationist Views. Subjects who answered a, b or c were put into the Creationist Views category while subjects who answered d or e were put into the Evolutionary Views category. The Freshman Pre-Instruction subjects did not differ significantly from the Freshman Post- Instruction in their attitudes on this topic. A previous study by Verhey in 2005 showed similar proportions of subjects (college students enrolled in an introductory biology course for biology majors) selecting creationist answers. The Seniors did differ

significantly from both the Freshman Pre-Instruction and the Freshman Post-Instruction in their attitudes on this topic. The Seniors do not appear different, however, from the

college students enrolled in an upper level biology course in evolution studied by Ingram and Nelson in 2006. These comparisons are summarized in Table 22. It should be noted that those students who selected answer c, “The Earth is ancient (many millions of years). Biological Evolution occurs, but God has intervened at critical points. God created

species through the laws of nature.”, are considered Theistic Evolutionists, and could feasibly be grouped with the Evolutionary Views category. This ‘re-grouping’ does not change any of the significance values presented in the Results Section, it merely provides an alternative comparative difference between this study’s groups and the previous study’s groups. This difference is detailed in Table 23. The substantial differences seen in the comparisons in Table 23, along with the grouping schemes in the previous research suggests that those students who self-selected as Theistic Evolutionists should be grouped as holding creationist views.

This research also suggests that understanding of evolutionary concepts improves with further education in biology. I found that when tested over evolutionary concepts, the average scores of biology major’s increase over time. Each group shows a significant difference (see Table 2), and those differences increase as instructional time increases. It is important to note, however, that only in the comparison between the two samples of freshmen are the same students involved. Also, not only were the senior data collected from a different set of subjects, it was a smaller set of subjects. The analysis does not account for the likely attrition from the biology major of some portion of students who may or may not understand evolution. Keeping that in mind, it is still clear that student understanding of evolution significantly improved after taking this particular introductory biology course.

The One-Way ANOVA that was performed on the data showed several significant differences between the subject groups. First, there were significant

differences between all groups in regards to their average quiz score. These differences revealed a trend of the score to increase as instructional time increased. In other words, the Seniors scored higher than the Freshman Post-Instruction, who in turn scored higher than the Freshman Pre-Instruction. Next the ANOVA showed significant differences between the Freshman Pre-Instruction and the Seniors in regards to their responses to question 9. The Freshman Pre-Instruction on average selected answers that were more towards agreeing that the Earth is 6,000 – 10,000 years old, while the Seniors selected answers that were on average more towards the disagree end of the scale. This suggests that there is a shift that occurs between a students’ arrival at Iowa State, and their graduation, where they become on average less likely to think that the Earth is 6,000 – 10,000 years old. It does not appear however, that this shift occurs during the students’ instruction in the Biology 211 lecture course. The third significant difference involved responses to question 10 (evolution is “just a theory”). The ANOVA revealed differences between the Freshman Pre-Instruction and the Freshman Post-Instruction and between the Freshman Pre-Instruction and the Seniors. The directionality of these differences shows that the Freshman Pre-Instruction were on average selecting answers significantly closer to the agree end of the scale than either of the other groups. These details, along with the fact that there is no significant difference between the answers of the Freshman Post- Instruction and the Seniors, suggest that the change in student understanding of the term “theory” occurs during their instruction in the Biology 211 lecture course. The last significant difference the ANOVA analysis detected was on the subjects responses to

question 11 (non-humans have evolved). Significant differences were detected between the Freshman Pre-Instruction and the Freshman Post-Instruction and between the

Freshman Pre-Instruction and the Seniors. In contrast to the ANOVA on question 10, directionality of these differences shows that the Freshman Pre-Instruction were on average selecting answers significantly closer to the disagree end of the scale than either of the other groups. These details, along with the fact that there is no significant

difference between the answers of the Freshman Post-Instruction and the Seniors, suggest that the change in student acceptance of non-human evolution occurs during their

instruction in the Biology 211 lecture course. There is not, however, any evidence that the subjects change their attitude toward human evolution with instruction. This result, taken in tandem with the result that for the same students, understanding of evolution does improve with instruction, is particularly noteworthy. This shows that the some students are separating the concepts of human evolution and non-human evolution in their minds. Why this is the case is not apparent from the qualitative data, but in other cases subjects have denied human evolution because they hold humans as being “special” or “above” other organisms. This may be what is occurring in these populations of students.

The Chi-Square analysis revealed that all subjects were not significantly shifting their views on religion and evolution over time. No relationship was detected between subject group membership (i.e. whether they were in the Senior, Freshman Pre-

Instruction, or Freshman Post-Instruction group), and subject choice on question 15. This implies that the subjects are not becoming more atheistic or agnostic over time.

as many creationist parents claim that they do not wish their children to lose their religious identity when they are exposed to instruction in evolution (Alters & Alters, 2001).

The Chi-Square analysis also showed that the subjects’ attitudes toward teaching Intelligent Design in public college science classes (Question 13, Table 14) changed over time. There were significant differences between the groups on their answer choices. An examination of the frequency data shows that in both instances the shift was toward answers that represent a negative view toward teaching Intelligent Design. In other words, as a student’s education in biology increases he/she is less likely to think that teaching Intelligent Design in public college science classes is a good idea.

Chi square analysis also provided insight into subject response to question 14. Again there were significant differences between the groups. The frequency data show a trend over time of selecting answers that represent a better understanding of the issues surrounding the teaching of evolution. With increasing instruction, subjects were more likely to blame a lack of public understanding and a perceived conflict between science and religion for the lack of public acceptance of evolution in the United States.

The ANCOVA on the subjects’ quiz score with group as the covariate and the responses to question 15 as an independent variable also provided an interesting result. When we take group into account, the subjects’ religious preference (i.e. their answer to question 15) shows no significant relationship to the subjects’ performance on the quiz over evolution. Only 4% of the variance in quiz score is explained by the responses to question 15, while 25.8% of the variance in quiz score is explained by subjects’ group membership. This suggests that it is the subjects’ educational experience, not their

religious preference that informs their quiz answers. Additionally, these results, along with the significant differences between the average quiz scores of the three groups suggest that subjects can learn evolutionary theory regardless of their religious preferences.

The MANOVA on group and quiz score with questions 8, 10, and 15 showed some significant and some important non-significant results. This MANOVA was performed on these three questions because together they represent a measure of the students’ opinion and understanding of the nature of science and their opinion on the origins of the diversity of life on Earth. When examining how the subjects answered questions 8, 10, and 15 together, only the subjects’ quiz score had any impact on their choices. Group membership showed no relationship to how the students answered the three questions together. No significant interaction was detected between group and quiz score in relation to the questions. When we tease apart the questions and examine which are actually being affected by group membership and quiz score, several significant distinctions appear. First, a subject’s quiz score is only significantly related to how they answer questions 8 and 10, the nature of science questions. A higher quiz score translates to a better grasp of nature of science issues regarding evolution(see Figures 1 & 2). Neither a subject’s quiz score, or group membership showed any relationship to how students answered question 15. We can also conclude that after instruction in an introductory biology course, understanding of the scientific use of the word theory improves, but decreases after several more years of college. These relationships are detailed in Table 19.

Thirty-eight correlations were detected between subjects’ responses to the

questions. Many of the correlations served as a check of the consistency of the subjects’ responses. For example, there is a positive correlation for the Freshman Pre-Instruction and the Seniors. In both those groups, the subjects that agreed that evolution is good science were likely to agree that both humans evolved. Additionally, both the Freshman Pre-Instruction and the Seniors who agreed that evolution is good science were likely to agree that non-humans evolved. The Freshman Post-Instruction subjects who agreed that evolution is good science however, were only likely to agree that humans evolved. There was no correlation between the Freshman Post-Instruction responses to evolution being good science and their response to non-human evolution. In all groups, there is a positive correlation where those subjects who agreed that the Earth was 6,000 – 10,000 years old were likely to agree that evolution is “just a theory”. Additionally, there is a positive correlation for the Freshman Pre-Instruction and Senior subjects who agreed that the Earth was 6,000 – 10,000 years old. Those subjects were likely to disagree that humans and non-humans evolved. The Freshman Post-Instruction who agreed that the Earth was 6,000 – 10,000 years old however, were likely to disagree that humans evolved. There was no correlation between Freshman Post-Instruction response to the age of the Earth and their responses to non-human evolution. Why the Freshman Post-Instruction did not answer as consistently in two instances regarding to non-human evolution is unclear. A third check of answer consistency was the correlations with question 10, the “just a theory” question. In all groups, those subjects who agreed that evolution is “just a theory” were likely to disagree that humans and non-humans evolved. The last

who agreed that non-humans evolved were likely to agree that humans evolved. All of these correlations suggest that the students were consistent in their answers across the survey. Additionally, they show that many expected trends are present in this subject population (e.g. that young Earth creationists don’t think evolution happened; people who think evolution is good science also think evolution occurred, etc). In all groups, the students who scored highly on the first five survey questions were more likely to agree that evolution is good science. This suggests three possible conclusions. The first is that those students who grasp evolutionary theory also hold a better understanding of science. The second is that those who understand science are more likely to grasp and accept biological evolution. The third interpretation is that understanding science and biological evolution are intricately intertwined.

In addition to acting as a check on the consistency of the data, the correlations involving subject responses to question 15 can also be examined for specific trend relationships. There are several worth mentioning. First, only the Freshman Pre- Instruction group subjects who scored highly on the 5 question quiz were also likely to select the more evolutionist choices (d and e) to question 15. This suggests that incoming freshman biology majors who already understand evolutionary theory are also likely to accept evolution as a well-supported scientific theory. Those Freshman Pre-Instruction and Seniors who selected the more evolutionist choices were more likely to agree that evolution is good science, that humans evolved, and that non-humans evolved. The Freshman Post-Instruction subjects that selected the more evolutionist choices were only more likely to agree that evolution is good science and that humans evolved. This suggests that those students who hold a greater understanding of what science is, and

accept that evolution occurred, are also more likely to accept evolution as a well- supported scientific theory. Lastly, in all groups, the subjects who selected more evolutionist choices to question 15 were also likely to disagree that evolution is just a theory and that the Earth is 6,000 – 10,000 years old. This also suggests that those students who accept evolution as a well-supported scientific theory also have a greater understanding of what science is and understand the various pieces of evidence for the ancient age of the Earth.

The qualitative data, while not statistically analyzed, is suggestive of several trends in the thinking of the subjects. For example, the first seven questions show the subjects shifting from Personal-type responses to Authoritative-type and Factual-type responses as instructional time increases. Questions 8, 9, and 10 show trends in subject response where the subjects are shifting from Belief-type responses to Detailed Claims- type responses as instructional time increases. The subject text responses to questions 11 and 12 show no apparent trend of any kind. The trends in all responses suggest that as instructional time increases, the students are less likely to support their answers with personal and belief statements, and more likely to cite an authority (i.e. a book or professor) or a fact learned during instruction. While subjects shift from citing, for example, the bible to citing the text book is not effective education, showing more subjects citing factual data is an improvement. This shift between sources of knowledge deserves more examination and research.

It is important to consider that some amount of the effects seen in the results section could be due to variables outside the focus of this study. First, the instructor for the Biology 211 lecture course from which we drew our Freshman Pre-Instruction and

Freshman Post-Instruction samples is known to put forth “extra effort” in regards to evolution and the nature of science. Thus the effects seen in this study may not be seen to this degree if a different lecture course were sampled. Attrition of students from the biology program may also be playing a part. There are always students who drop from the program in each term. This loss may affect not only the comparison between the freshman and seniors, but between the two freshman groups as well. In regards to the senior group, a much less complete sample was collected than in the other groups. This could lead to bias in our data toward those students who felt inclined to complete the survey. These limitations remain and should be kept in mind when evaluating the data.