Students with religious beliefs often find it difficult to accept the theory of evolution. It is important that educators feel comfortable addressing student questions on the compatibility of evolution and religion. We designed an online professional development course that taught the foundational principles of both evolution and religion in order to assist secular and non-secular educators in helping their students overcome religious barriers to evolution. This course increased the confidence of science educators to help students resolve perceived conflict between evolution and religion. Utilizing a reconciliation model will help religious educators drive science acceptance.
{"title":"Online Professional Development Course Helps Secondary Educators Increase Their Confidence in Teaching Evolution to Religious Audiences","authors":"Kenneth Harrington, Hunter Nelson, Jordon Ockey, Austin Gibson, Jamie Jensen","doi":"10.1525/abt.2024.86.2.78","DOIUrl":"https://doi.org/10.1525/abt.2024.86.2.78","url":null,"abstract":"Students with religious beliefs often find it difficult to accept the theory of evolution. It is important that educators feel comfortable addressing student questions on the compatibility of evolution and religion. We designed an online professional development course that taught the foundational principles of both evolution and religion in order to assist secular and non-secular educators in helping their students overcome religious barriers to evolution. This course increased the confidence of science educators to help students resolve perceived conflict between evolution and religion. Utilizing a reconciliation model will help religious educators drive science acceptance.","PeriodicalId":513114,"journal":{"name":"The American Biology Teacher","volume":"16 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139883879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1525/abt.2024.86.2.87
Britteny Berumen, Misty Boatman, Mark W. Bland
Evolutionary theory is fundamental to biology, yet evolution instruction in high schools has often been unsatisfactory. How or whether high school biology teachers teach evolution is influenced by their own acceptance or rejection of evolutionary theory, parents’ and community members’ views, and in the case of some private schools, their religious affiliations. Studies documenting how evolution is taught in public high schools have been conducted, yet private schools remain underresearched. Arkansas high school biology teachers employed by public and private schools were invited to complete a survey composed of the Measure of Acceptance of the Theory of Evolution (MATE) and other items designed to allow comparison of their treatment of topics within evolutionary theory. Specifically, we sought to compare public and private teachers’ acceptance of evolution, how they teach it in their classrooms, and how their acceptance of the validity of evolution compares with four other widely accepted scientific theories (cell, gene, germ, and atomic). Results suggest that public school teachers have higher levels of acceptance of evolution than private school teachers. However, teachers in both public and private schools reported lower acceptance of the validity of evolutionary theory compared with the other four scientific theories. Across topics within evolution, natural selection was given the most treatment while human evolution was given the least.
{"title":"Public vs. Private","authors":"Britteny Berumen, Misty Boatman, Mark W. Bland","doi":"10.1525/abt.2024.86.2.87","DOIUrl":"https://doi.org/10.1525/abt.2024.86.2.87","url":null,"abstract":"Evolutionary theory is fundamental to biology, yet evolution instruction in high schools has often been unsatisfactory. How or whether high school biology teachers teach evolution is influenced by their own acceptance or rejection of evolutionary theory, parents’ and community members’ views, and in the case of some private schools, their religious affiliations. Studies documenting how evolution is taught in public high schools have been conducted, yet private schools remain underresearched.\u0000 Arkansas high school biology teachers employed by public and private schools were invited to complete a survey composed of the Measure of Acceptance of the Theory of Evolution (MATE) and other items designed to allow comparison of their treatment of topics within evolutionary theory. Specifically, we sought to compare public and private teachers’ acceptance of evolution, how they teach it in their classrooms, and how their acceptance of the validity of evolution compares with four other widely accepted scientific theories (cell, gene, germ, and atomic). Results suggest that public school teachers have higher levels of acceptance of evolution than private school teachers. However, teachers in both public and private schools reported lower acceptance of the validity of evolutionary theory compared with the other four scientific theories. Across topics within evolution, natural selection was given the most treatment while human evolution was given the least.","PeriodicalId":513114,"journal":{"name":"The American Biology Teacher","volume":"116 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139875914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1525/abt.2024.86.2.117
Jeffrey D. Sack, Daniel G. Ferguson
{"title":"Reconciling Evolution","authors":"Jeffrey D. Sack, Daniel G. Ferguson","doi":"10.1525/abt.2024.86.2.117","DOIUrl":"https://doi.org/10.1525/abt.2024.86.2.117","url":null,"abstract":"","PeriodicalId":513114,"journal":{"name":"The American Biology Teacher","volume":"4 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139875969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1525/abt.2024.86.2.56
Anthony W. Lorsbach, Allison Antink Meyer
This lesson used the correspondence of Charles Darwin as an exploration of nature of science (NOS) in a historical context. Specifically, we used his original correspondence about his “provisional hypothesis” of pangenesis as a novel way to explore a scientist’s social community. Darwin’s community of friends and colleagues in the natural sciences at the time of his writing of his 1868 book Variations formed the basis of this lesson. One basic descriptor of NOS, science as a human endeavor, was used to drive explicit reflection. These letters were rich in detail regarding the idea of science as a community of practice. Our elementary education students’ responses indicate the letters surprised them in how personal the correspondents were with one another and how reliant Darwin was on his friends and colleagues for input on his work. Darwin became human as students imagined Darwin’s mental state and how he wrestled with his idea and made it public. Students learned that despite Darwin’s fame, his idea of pangenesis lacked empirical evidence and thus received little support. They discovered an eminent scientist who was insecure and nervous and who worked hard to develop, study, and publicize his novel idea. This contrasts with popular views of major scientific figures as natural geniuses rather than their success resulting from labor and perseverance.
{"title":"Using Darwin’s Pangenesis Correspondences to Examine Science as a Human Endeavor","authors":"Anthony W. Lorsbach, Allison Antink Meyer","doi":"10.1525/abt.2024.86.2.56","DOIUrl":"https://doi.org/10.1525/abt.2024.86.2.56","url":null,"abstract":"This lesson used the correspondence of Charles Darwin as an exploration of nature of science (NOS) in a historical context. Specifically, we used his original correspondence about his “provisional hypothesis” of pangenesis as a novel way to explore a scientist’s social community. Darwin’s community of friends and colleagues in the natural sciences at the time of his writing of his 1868 book Variations formed the basis of this lesson. One basic descriptor of NOS, science as a human endeavor, was used to drive explicit reflection. These letters were rich in detail regarding the idea of science as a community of practice. Our elementary education students’ responses indicate the letters surprised them in how personal the correspondents were with one another and how reliant Darwin was on his friends and colleagues for input on his work. Darwin became human as students imagined Darwin’s mental state and how he wrestled with his idea and made it public. Students learned that despite Darwin’s fame, his idea of pangenesis lacked empirical evidence and thus received little support. They discovered an eminent scientist who was insecure and nervous and who worked hard to develop, study, and publicize his novel idea. This contrasts with popular views of major scientific figures as natural geniuses rather than their success resulting from labor and perseverance.","PeriodicalId":513114,"journal":{"name":"The American Biology Teacher","volume":"17 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139817171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1525/abt.2024.86.2.87
Britteny Berumen, Misty Boatman, Mark W. Bland
Evolutionary theory is fundamental to biology, yet evolution instruction in high schools has often been unsatisfactory. How or whether high school biology teachers teach evolution is influenced by their own acceptance or rejection of evolutionary theory, parents’ and community members’ views, and in the case of some private schools, their religious affiliations. Studies documenting how evolution is taught in public high schools have been conducted, yet private schools remain underresearched. Arkansas high school biology teachers employed by public and private schools were invited to complete a survey composed of the Measure of Acceptance of the Theory of Evolution (MATE) and other items designed to allow comparison of their treatment of topics within evolutionary theory. Specifically, we sought to compare public and private teachers’ acceptance of evolution, how they teach it in their classrooms, and how their acceptance of the validity of evolution compares with four other widely accepted scientific theories (cell, gene, germ, and atomic). Results suggest that public school teachers have higher levels of acceptance of evolution than private school teachers. However, teachers in both public and private schools reported lower acceptance of the validity of evolutionary theory compared with the other four scientific theories. Across topics within evolution, natural selection was given the most treatment while human evolution was given the least.
{"title":"Public vs. Private","authors":"Britteny Berumen, Misty Boatman, Mark W. Bland","doi":"10.1525/abt.2024.86.2.87","DOIUrl":"https://doi.org/10.1525/abt.2024.86.2.87","url":null,"abstract":"Evolutionary theory is fundamental to biology, yet evolution instruction in high schools has often been unsatisfactory. How or whether high school biology teachers teach evolution is influenced by their own acceptance or rejection of evolutionary theory, parents’ and community members’ views, and in the case of some private schools, their religious affiliations. Studies documenting how evolution is taught in public high schools have been conducted, yet private schools remain underresearched.\u0000 Arkansas high school biology teachers employed by public and private schools were invited to complete a survey composed of the Measure of Acceptance of the Theory of Evolution (MATE) and other items designed to allow comparison of their treatment of topics within evolutionary theory. Specifically, we sought to compare public and private teachers’ acceptance of evolution, how they teach it in their classrooms, and how their acceptance of the validity of evolution compares with four other widely accepted scientific theories (cell, gene, germ, and atomic). Results suggest that public school teachers have higher levels of acceptance of evolution than private school teachers. However, teachers in both public and private schools reported lower acceptance of the validity of evolutionary theory compared with the other four scientific theories. Across topics within evolution, natural selection was given the most treatment while human evolution was given the least.","PeriodicalId":513114,"journal":{"name":"The American Biology Teacher","volume":"29 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139816139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Students with religious beliefs often find it difficult to accept the theory of evolution. It is important that educators feel comfortable addressing student questions on the compatibility of evolution and religion. We designed an online professional development course that taught the foundational principles of both evolution and religion in order to assist secular and non-secular educators in helping their students overcome religious barriers to evolution. This course increased the confidence of science educators to help students resolve perceived conflict between evolution and religion. Utilizing a reconciliation model will help religious educators drive science acceptance.
{"title":"Online Professional Development Course Helps Secondary Educators Increase Their Confidence in Teaching Evolution to Religious Audiences","authors":"Kenneth Harrington, Hunter Nelson, Jordon Ockey, Austin Gibson, Jamie Jensen","doi":"10.1525/abt.2024.86.2.78","DOIUrl":"https://doi.org/10.1525/abt.2024.86.2.78","url":null,"abstract":"Students with religious beliefs often find it difficult to accept the theory of evolution. It is important that educators feel comfortable addressing student questions on the compatibility of evolution and religion. We designed an online professional development course that taught the foundational principles of both evolution and religion in order to assist secular and non-secular educators in helping their students overcome religious barriers to evolution. This course increased the confidence of science educators to help students resolve perceived conflict between evolution and religion. Utilizing a reconciliation model will help religious educators drive science acceptance.","PeriodicalId":513114,"journal":{"name":"The American Biology Teacher","volume":"58 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139823840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1525/abt.2024.86.2.71
Kristy L Daniel, Daniel Ferguson, E. A. Leone, C. Bucklin
Phylogenetic tree diagrams are commonly found in introductory biology curricula and represent the evolutionary relationships of organisms. Tree-thinking, or the ability to accurately interpret, use, and generate these phylogenetic representations, involves a challenging set of skills for students to learn. Although many introductory biology courses incorporate tree-thinking instruction, few studies have identified which instructional methods provide the best learning gains for students. We gathered data from 884 introductory biology students using the Basic Evolutionary Tree-Thinking Skills Inventory (BETTSI) to measure tree-thinking learning gains. We measured tree-thinking differences across five sections of introductory biology, each offering a different instructional intervention, and compared differences among STEM majors and non-STEM majors. After calculating paired differences, we performed a two-way repeated measure analysis of variance (ANOVA) and Scheffe’s post hoc test to identify significant differences among and between the different interventions. We found that students who engaged in active tree-thinking instruction had significantly higher tree-thinking learning gains than students who participated in passive or no instruction. Furthermore, these learning gains became even more significant as active-learning became more multifaceted. These active-learning approaches also removed knowledge gaps between STEM majors and non-majors. Instructors must select explicit and active pedagogical approaches to support student tree-thinking to accomplish positive learning gains for all students.
{"title":"A Comparison of Measured Outcomes across Tree-Thinking Interventions","authors":"Kristy L Daniel, Daniel Ferguson, E. A. Leone, C. Bucklin","doi":"10.1525/abt.2024.86.2.71","DOIUrl":"https://doi.org/10.1525/abt.2024.86.2.71","url":null,"abstract":"Phylogenetic tree diagrams are commonly found in introductory biology curricula and represent the evolutionary relationships of organisms. Tree-thinking, or the ability to accurately interpret, use, and generate these phylogenetic representations, involves a challenging set of skills for students to learn. Although many introductory biology courses incorporate tree-thinking instruction, few studies have identified which instructional methods provide the best learning gains for students. We gathered data from 884 introductory biology students using the Basic Evolutionary Tree-Thinking Skills Inventory (BETTSI) to measure tree-thinking learning gains. We measured tree-thinking differences across five sections of introductory biology, each offering a different instructional intervention, and compared differences among STEM majors and non-STEM majors. After calculating paired differences, we performed a two-way repeated measure analysis of variance (ANOVA) and Scheffe’s post hoc test to identify significant differences among and between the different interventions. We found that students who engaged in active tree-thinking instruction had significantly higher tree-thinking learning gains than students who participated in passive or no instruction. Furthermore, these learning gains became even more significant as active-learning became more multifaceted. These active-learning approaches also removed knowledge gaps between STEM majors and non-majors. Instructors must select explicit and active pedagogical approaches to support student tree-thinking to accomplish positive learning gains for all students.","PeriodicalId":513114,"journal":{"name":"The American Biology Teacher","volume":"228 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139827676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1525/abt.2024.86.2.56
Anthony W. Lorsbach, Allison Antink Meyer
This lesson used the correspondence of Charles Darwin as an exploration of nature of science (NOS) in a historical context. Specifically, we used his original correspondence about his “provisional hypothesis” of pangenesis as a novel way to explore a scientist’s social community. Darwin’s community of friends and colleagues in the natural sciences at the time of his writing of his 1868 book Variations formed the basis of this lesson. One basic descriptor of NOS, science as a human endeavor, was used to drive explicit reflection. These letters were rich in detail regarding the idea of science as a community of practice. Our elementary education students’ responses indicate the letters surprised them in how personal the correspondents were with one another and how reliant Darwin was on his friends and colleagues for input on his work. Darwin became human as students imagined Darwin’s mental state and how he wrestled with his idea and made it public. Students learned that despite Darwin’s fame, his idea of pangenesis lacked empirical evidence and thus received little support. They discovered an eminent scientist who was insecure and nervous and who worked hard to develop, study, and publicize his novel idea. This contrasts with popular views of major scientific figures as natural geniuses rather than their success resulting from labor and perseverance.
{"title":"Using Darwin’s Pangenesis Correspondences to Examine Science as a Human Endeavor","authors":"Anthony W. Lorsbach, Allison Antink Meyer","doi":"10.1525/abt.2024.86.2.56","DOIUrl":"https://doi.org/10.1525/abt.2024.86.2.56","url":null,"abstract":"This lesson used the correspondence of Charles Darwin as an exploration of nature of science (NOS) in a historical context. Specifically, we used his original correspondence about his “provisional hypothesis” of pangenesis as a novel way to explore a scientist’s social community. Darwin’s community of friends and colleagues in the natural sciences at the time of his writing of his 1868 book Variations formed the basis of this lesson. One basic descriptor of NOS, science as a human endeavor, was used to drive explicit reflection. These letters were rich in detail regarding the idea of science as a community of practice. Our elementary education students’ responses indicate the letters surprised them in how personal the correspondents were with one another and how reliant Darwin was on his friends and colleagues for input on his work. Darwin became human as students imagined Darwin’s mental state and how he wrestled with his idea and made it public. Students learned that despite Darwin’s fame, his idea of pangenesis lacked empirical evidence and thus received little support. They discovered an eminent scientist who was insecure and nervous and who worked hard to develop, study, and publicize his novel idea. This contrasts with popular views of major scientific figures as natural geniuses rather than their success resulting from labor and perseverance.","PeriodicalId":513114,"journal":{"name":"The American Biology Teacher","volume":"61 1-4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139877071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1525/abt.2024.86.2.108
Agnieszka Szarecka, Christopher Dobson
Computer modeling and protein structure visualization tools are effective and engaging ways of presenting various molecular biology concepts to high school and college students. Here, we describe a series of activities and exercises that use online bioinformatics databases and programs to search for and obtain protein sequence and structure data and use it to build homology models of proteins. Exercises in homology modeling can serve the pedagogical purpose of introducing and illustrating the concept of homology within gene and protein families, which results in conservation of the 3D structures of proteins and allows us to predict structures when experimental data are not available.
{"title":"A Tool to Teach Evolution of Protein Sequences and Structures","authors":"Agnieszka Szarecka, Christopher Dobson","doi":"10.1525/abt.2024.86.2.108","DOIUrl":"https://doi.org/10.1525/abt.2024.86.2.108","url":null,"abstract":"Computer modeling and protein structure visualization tools are effective and engaging ways of presenting various molecular biology concepts to high school and college students. Here, we describe a series of activities and exercises that use online bioinformatics databases and programs to search for and obtain protein sequence and structure data and use it to build homology models of proteins. Exercises in homology modeling can serve the pedagogical purpose of introducing and illustrating the concept of homology within gene and protein families, which results in conservation of the 3D structures of proteins and allows us to predict structures when experimental data are not available.","PeriodicalId":513114,"journal":{"name":"The American Biology Teacher","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139821064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1525/abt.2024.86.2.101
Qin Qi, J. A. Stacey, Nureeni Wright, S. Tetu, M. R. Gillings
Understanding that evolution progresses through generation of DNA variants followed by selection is a key learning outcome for biology students. We designed an integrated and innovative undergraduate laboratory exercise using Saccharomyces cerevisiae to demonstrate these principles. Students perform in vitro experimental evolution by repeatedly propagating large or small yeast colonies on a weekly basis. Small-colony variants known as petites arise by mutations that disrupt aerobic respiration. To demonstrate the effects of increased mutation rates, half of the selection lines are exposed to ultraviolet irradiation. To understand how the petite phenotype arises, polymerase chain reaction (PCR) is performed to examine mitochondrial DNA, while biochemical assays are used to assess the ability of petites to undergo aerobic respiration. This exercise demonstrates evolution by artificial selection over a suitably short timeframe and links the results to a critical biochemical process: the role of mitochondria in aerobic respiration and ATP production. By implementing these experiments, we successfully demonstrated that the frequencies of petite mutants in evolved populations varied according to the selection pressure we applied, and that petite mutants carried deletions in mitochondrial DNA as anticipated. Through an integrated learning context, this practical exercise promotes fundamental understanding of evolutionary processes and fosters critical thinking skills.
理解进化是通过 DNA 变异的产生和选择进行的,是生物专业学生的一项重要学习成果。我们设计了一个使用酿酒酵母的综合创新本科生实验练习来演示这些原理。学生们每周通过反复繁殖大或小的酵母菌群来进行体外实验进化。小菌落变种被称为 "小酵母"(petites),是通过破坏有氧呼吸的突变产生的。为了证明突变率增加的影响,一半的选择系暴露在紫外线照射下。为了了解 "小不点 "表型是如何产生的,我们进行了聚合酶链式反应(PCR)来检测线粒体 DNA,同时使用生化检测来评估 "小不点 "进行有氧呼吸的能力。这项工作展示了在适当短的时间内通过人工选择进行的进化,并将结果与一个关键的生化过程联系起来:线粒体在有氧呼吸和 ATP 生产中的作用。通过实施这些实验,我们成功地证明了进化种群中娇小突变体的频率随我们施加的选择压力而变化,而且娇小突变体如预期的那样携带线粒体DNA缺失。通过综合学习情境,该实践练习促进了对进化过程的基本理解,并培养了批判性思维能力。
{"title":"An Integrated Undergraduate Laboratory Exercise to Demonstrate Microbial Evolution","authors":"Qin Qi, J. A. Stacey, Nureeni Wright, S. Tetu, M. R. Gillings","doi":"10.1525/abt.2024.86.2.101","DOIUrl":"https://doi.org/10.1525/abt.2024.86.2.101","url":null,"abstract":"Understanding that evolution progresses through generation of DNA variants followed by selection is a key learning outcome for biology students. We designed an integrated and innovative undergraduate laboratory exercise using Saccharomyces cerevisiae to demonstrate these principles. Students perform in vitro experimental evolution by repeatedly propagating large or small yeast colonies on a weekly basis. Small-colony variants known as petites arise by mutations that disrupt aerobic respiration. To demonstrate the effects of increased mutation rates, half of the selection lines are exposed to ultraviolet irradiation. To understand how the petite phenotype arises, polymerase chain reaction (PCR) is performed to examine mitochondrial DNA, while biochemical assays are used to assess the ability of petites to undergo aerobic respiration. This exercise demonstrates evolution by artificial selection over a suitably short timeframe and links the results to a critical biochemical process: the role of mitochondria in aerobic respiration and ATP production. By implementing these experiments, we successfully demonstrated that the frequencies of petite mutants in evolved populations varied according to the selection pressure we applied, and that petite mutants carried deletions in mitochondrial DNA as anticipated. Through an integrated learning context, this practical exercise promotes fundamental understanding of evolutionary processes and fosters critical thinking skills.","PeriodicalId":513114,"journal":{"name":"The American Biology Teacher","volume":"195 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139824467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}