Sehoya Cotner

IS THE AGE OF THE EARTH ONE OF OUR “SOREST TROUBLES?” STUDENTS’ PERCEPTIONS ABOUT DEEP TIME AFFECT THEIR ACCEPTANCE OF EVOLUTIONARY THEORY

When Charles Darwin was developing his ideas for On the Origin of Species, the most widely accepted estimates of Earth’s age were those of William Thomson (later Lord Kelvin). Kelvin used calculations involving thermodynamics to argue that Earth is only 20–100 million years old—an age far too brief to accommodate evolution by natural selection. Darwin referred to Thomson’s claim as one of his “sorest troubles,” for Darwin understood that the history of life on Earth ultimately relies on geology. Darwin suspected that Earth was much older than Thomson claimed, but Thomson’s enormous stature as a scientist obliged Darwin to reconcile his claims with Kelvin’s data. To accommodate Kelvin’s timeline, Darwin proposed pangenesis as an explanation of inheritance (i.e., every sperm and egg contained “gemmules thrown off from each different unit throughout the body”). Darwin’s explanation sped evolution while avoiding Lamarck’s quasi-spiritual sources of acquired traits. However, Darwin’s explanation of inheritance was wrong (see discussion in Moore et al. 2009a). The age of Earth remains a divisive topic in the modern evolution–creationism controversy. Whereas mainstream science has long acknowledged that Earth is approximately 4.5 billion years old, a vocal group of citizens and religious activists continue to insist that Earth is less than 10,000 years old. Although most geocentrists and flat-Earth advocates have capitulated to scientific evidence, young-Earth creationists continue to reject scientific evidence in favor of religious dictum to claim that Earth is less than 10,000 years old. These antiscience claims have been surprisingly popular with the public. For example, a Gallup Poll in early 2009 reported that “On Darwin’s [200th] Birthday, Only 4 in 10 Believe in Evolution” (Newport 2009), and Berkman et al. (2008) noted that “16% [of biology teachers] believed that human beings were created by God in their present form at one time within the last 10,000 years.” In another study, 12.5% of students were young-Earth creationists (Rutledge and Warden 2000), as are 10%–14% of biology majors (Moore and Cotner 2009). Answers in Genesis’ (AiG) Creation Museum, along with the

Educational Malpractice: The Impact of Including Creationism in High School Biology Courses

27 million in donations required to build it, attest to the appeal of young-Earth creationism. Indeed, AiG’s income for 2005 exceeded

Minimal Impact of Organic Chemistry Prerequisite on Student Performance in Introductory Biochemistry

13 million, and that of the Institute for Creation Research (ICR, another religious organization based on young-Earth creationism) exceeded

A Novel Laboratory Activity for Teaching about the Evolution of Multicellularity

7 million. For comparison, the 2005 income of National Center for Science Education—the nation’s leading organization that defends the teaching of evolution in public schools—was

Exams disadvantage women in introductory biology

College students whose recollections of their high school biology courses included creationism were significantly more likely to invoke creationism-based answers on questions derived from the Material Acceptance of the Theory of Evolution (MATE) instrument than were students whose recollections of their high school biology courses included evolution but not creationism. On average, students who were taught neither evolution nor creationism in their high school biology courses exhibited intermediary responses on the MATE instrument. These results suggest that (1) high school teachers’ treatments of evolution and creationism have a lasting impact and (2) the inclusion of creationism in high school biology courses increases the probability that students accept creationism and reject evolution when they arrive at college. These results are discussed relative to the impact of high school biology courses on students’ subsequent acceptance of evolution and creationism.

In Galápagos … and Uncomfortable with Evolution

Curriculum design assumes that successful completion of prerequisite courses will have a positive impact on student performance in courses that require the prerequisite. We recently had the opportunity to test this assumption concerning the relationship between completion of the organic chemistry prerequisite and performance in introductory biochemistry. We found no statistically significant differences between average biochemistry grades or grade distribution among students with or without the organic chemistry prerequisite. However, students who had not completed the organic chemistry prerequisite before biochemistry were more likely to withdraw from the course than those who had completed the prerequisite. In contrast to the lack of correlation between performance in biochemistry and completion of organic chemistry, we observed a strong, highly significant positive relationship between cumulative GPA and the biochemistry grade. Our data suggest that excluding students without organic chemistry would have less positive impact on student success in biochemistry than would providing additional support for all students who enroll in biochemistry with a cumulative GPA below 2.5.

A Call to Develop Course-Based Undergraduate Research Experiences (CUREs) for Nonmajors Courses

Abstract The evolution of complexity remains one of the most challenging topics in biology to teach effectively. We present a novel laboratory activity, modeled on a recent experimental breakthrough, in which students experimentally evolve simple multicellularity using single-celled yeast (Saccharomyces cerevisiae). By simply selecting for faster settling through liquid media, yeast evolve to form snowflakeshaped multicelled clusters that continue to evolve as multicellular individuals. We present core experimental and curriculum tools, including discussion topics and assessment instruments, and provide suggestions for teacher customization. Prelab and postlab assessments demonstrate that this lab effectively teaches fundamental concepts about the transition to multicellularity. Yeast strains, the student lab manual, and an introductory presentation are available free of charge.

Bold, Sedentary Fathead Minnows Have More Parasites

The gender gap in STEM fields has prompted a great deal of discussion, but what factors underlie performance deficits remain poorly understood. We show that female students underperformed on exams compared to their male counterparts across ten large introductory biology course sections in fall 2016 (N > 1500 students). Females also reported higher levels of test anxiety and course-relevant science interest. Results from mediation analyses revealed an intriguing pattern: for female students only, and regardless of their academic standing, test anxiety negatively impacted exam performance, while interest in the course-specific science topics increased exam performance. Thus, instructors seeking equitable classrooms can aim to decrease test anxiety and increase student interest in science course content. We provide strategies for mitigating test anxiety and suggestions for alignment of course content with student interest, with the hope of successfully reimagining the STEM pathway as one that is equally accessible to all.

A Model for a Course-Based Undergraduate Research Experience (CURE) in a Field Setting †

Today in Galápagos, Darwin and evolution are everywhere (Moore and Cotner 2013). For example, the town of Puerto Baquerizo Moreno (on San Cristóbal) is home to ‘Darwin’s Shop, since 1835 ...’ (Figure 1), a huge statue of Darwin overlooks Frigatebird Bay (where Darwin first set foot in the archipelago), and a bust of Charles Darwin greets visitors along Malecón Charles Darwin, the village’s main street. Similarly, the Charles Darwin Research Station is at the end of Charles Darwin Avenue in Puerto Ayora (on Santa Cruz), where dozens of vendors hawk Darwin’s likeness and statements about evolution on t-shirts, backpacks, coffee mugs and stickers. These items are popular with tourists, who are the basis of 70% of the islands’ economy (Honey 2008). Darwin made Galápagos famous, and the residents’ livelihoods depend on tourists who come to the islands to learn more about Darwin’s visit and see the organisms that contributed to Darwin’s ideas. In light of this, we wondered how the biology teachers in the islands perceive evolution. For example, what do biology teachers in Galápagos know– and accept–about the core tenets of evolutionary thought? What do biology teachers in Galápagos know about Charles Darwin’s connection to the archipelago? We addressed these and other questions by surveying teachers on the three most populated islands in the archipelago–Santa Cruz, San Cristóbal and Isabela (Floreana Island, with a population fewer than 200 people, was not included in this study because it has only an elementary school). Specifically, we measured teachers’ knowledge of evolution via the Knowledge of Evolution Exam (KEE; Moore and Cotner 2009; Moore, Brooks, and Cotner 2011; Rissler, Duncan, and Caruso 2014), a 10-item quiz designed to target basic understanding of evolution and reveal common misconceptions. We also created several questions to address knowledge and perceptions specific to Galápagos (e.g. ‘Galápagos is closely connected to the history of evolutionary thought’ and ‘I am proud of the connection between Galápagos and evolutionary thought’). Christian Bastidas Bustos, the District Analyst for Support, Monitoring and Regulation in the office of Ecuador’s Minister of Education, approved our survey, identified the teachers in Galápagos who

Small group gender ratios impact biology class performance and peer evaluations

A discussion of course-based undergraduate research experiences (CUREs) for non–science majors (nonmajors) that summarizes the state of knowledge of best practices for nonmajors CUREs, identifies future research priorities, and recommends tools to align research questions with student outcomes.