Biology

Majors and minors

The Biology Department offers a course major, course minor, honors major and honors minor. In addition, special majors in biochemistry and neuroscience are regularly offered in cooperation with the Chemistry and Biochemistry and Psychology departments, respectively. A student may choose an interdisciplinary minor in environmental studies, which includes courses in the Biology Department. In addition, the department has also supported special majors as described below.

Sample paths through the discipline

As pointed out in the introduction, there are many paths to a biology major. Following are some ideas to keep in mind as you plan your schedule.

Getting started as a biology major: Nearly all majors take BIOL 001 and/or BIOL 002 during their first year. These two courses may be taken in either order and it is not uncommon for prospective majors to take BIOL 002 during the spring semester of their first year, and BIOL 001 during the fall semester of their second year. Students who realize their interest in biology later have also taken both courses during their sophomore year and successfully completed the major in eight semesters. We generally encourage all students to take at least one of the introductory courses, even if they have AP/IB credit. BIOL 001 is always offered in the fall semester, and BIOL 002 always in the spring semester.

We encourage majors to fulfill the mathematics and chemistry requirements for the major during their first two years. In particular, some intermediate level courses require CHEM 010 and CHEM 022. Completion of those chemistry courses gives more flexibility in biology course choice. However, we are willing to work with students to craft the best path for each individual.

Continuing as a biology major: Because most intermediate level courses require both BIOL 001 and BIOL 002 (or AP/IB credit), taking both courses before continuing on in the field usually serves students best. For planning purposes, most Group III intermediate-level courses are taught in the fall semester, and most Group I intermediate-level courses are taught in the spring semester. Some Group II courses are taught in spring and others in fall.

The seminar course(s) you are most interested in taking may influence your other course choices. In addition to your own interests, prerequisites for seminars (which may consist of a specific intermediate-level course), faculty leave schedules, and study abroad considerations may constrain your course choice and schedule.

Some faculty strongly encourage students interested in doing research with them to take at least one course with them before working on a research project. It is important to talk to specific faculty members you are interested in working with to understand their specific requirements for work in their laboratory.

Completion of the biology major: Course majors must pass the comprehensive exam (BIOL 097 Themes in Biology) during the spring semester of the senior year. Honors majors are required to enroll in at least one credit of BIOL 180 (often but not always in the fall semester of their senior year), and in Senior Honors Study (BIOL 199), which is taken in the spring semester of the senior year.

Acceptance criteria

1. Three courses (or advanced placement credit and two courses) in biology. If the student does not have an AP, IB, or transfer credit, both BIOL 001 and BIOL 002 are required.  Courses numbered 003-009 may not be used for acceptance to the major.
2. CHEM 010, or placement approved by the Chemistry and Biochemistry Department.
3. Swarthmore College credit for two courses in mathematics or statistics (not STAT 001, MATH 003, or MATH 020). Alternatively, students may complete Calculus II (MATH 025) to satisfy the math requirement. Students who place out of Math 025, by the placement test administered by the Mathematics and Statistics Department, will have satisfied the math requirement for the major. The Biology Department strongly recommends a course in statistics for majors.
4. Applicants must have an average grade of C (2.00) or better in BIOL 001 and BIOL 002
   1. AP/IB credit may be used as a replacement for one of the introductory courses after another biology course with laboratory is completed. Note that the department strongly encourages all students with AP/IB credit to take both of the introductory courses. If both BIOL 001 and 002 are taken, the AP credit is discounted. If an AP/IB credit is used as a replacement for BIOL 001 or BIOL 002, this counts towards the credits needed for the major. 
5. In addition, the applicant must have an average grade of C (2.00) or better in all courses taken in the Biology Department, and an overall average grade of C (2.00) or better in the Division of Natural Sciences and Engineering at Swarthmore College (biology, physics and astronomy, chemistry and biochemistry, mathematics and statistics, engineering, and computer science). Unpublished grades in biology for the first semester of the first year will be considered in the C average requirement; passing grades of CR in other courses in the Division of Natural Sciences and Engineering are acceptable. 
6. Students who have not completed the requirements for acceptance to the major will be deferred until the end of the fifth semester.  Students who have not completed all requirements for acceptance to the major by the end of the fifth semester will no longer have priority in lotteries based on their sophomore plan, and will need to re-apply for the major before the last day of classes in their junior year.

Requirements for graduation

1. Credit requirements: Students majoring in biology must complete a minimum of eight biology credits, at least five of which must be taken at Swarthmore College.  Courses taken during the first semester of the first year are all CR/NC.  After this semester, only one Biology course with a recorded grade of CR can be used to fulfill the requirements of a Biology major.  Seminars (100-139) and BIOL 097 may not be taken CR/NC.  CHEM 038 (Biochemistry) may be counted as one of the eight biology credits. If an AP/IB credit is used as a replacement for BIOL 001 or BIOL 002, this credit counts towards completion of the 8 credits for the major. SP credits cannot be used to satisfy the eight credit requirement. Note: For the Class of 2026 and beyond: Biology majors will be required to complete 9 biology credits and CHEM 038 will no longer be accepted towards a Biology major.
2. Distribution requirements: Students majoring in biology must pass at least one intermediate course in each of the following three groups: I. Cellular and Molecular Biology, II. Organismal Biology and III. Population Biology. The digit in the tens place of the course number signifies the group of the course (i.e., BIOL 010 is a Group I course, BIOL 020 is a Group II course and BIOL 030 is a Group III course).
   1. Students majoring in biology may count only one course numbered 003-009 toward the required Biology credits. Courses numbered 003-009 do not meet the Group distribution requirement.
   2. BIOL 093 (Directed Reading) and BIOL 094 (Independent Research) count as credits toward the biology major but cannot be used as distribution requirements. No more than two credits in BIOL 093, BIOL 094 or BIOL 093 and BIOL 094 in combination may be used to satisfy the credit requirements for the Biology major.
   3. CHEM 038 (Biochemistry) may be counted as a Group I course and as one of the Biology credits required for the major. In this case, the CHEM 038 grade will be counted towards the biology GPA. Note: For the Class of 2026 and beyond, CHEM 038 will no longer be accepted towards a Biology major.
3. Seminar requirement: All biology majors are required to take at least one seminar (with a course number greater than 100). A seminar in biology is defined as an advanced offering that uses primary rather than secondary source materials and encourages active student participation in presentation and discussion of materials. Note that all seminars have at least one intermediate level course (numbered 10-39) as a prerequisite; the particular prerequisites for seminars vary and should be considered during selection of intermediate level courses.  All seminars must be taken at Swarthmore College.  Students must earn a B grade or better in the intermediate course used as the seminar prerequisite to enroll in a seminar.

4. NSE breadth course requirement:  Students majoring in Biology must complete two courses from the list of  NSE breadth courses (below).

5. Comprehensive examination: All biology course majors must satisfy the College requirement of passing a comprehensive examination given by the major department. In biology, this comprehensive examination is the lecture series BIOL 097, Themes in Biology. BIOL 097 is offered only in the spring semester and is usually taken by students during the spring of their senior year. This course features a series of visiting speakers who give presentations connected by an overarching theme that can be addressed from all areas of biology. It enables faculty and students to interact on an intellectually challenging project, allows students to think about a topic from a variety of levels of biological organization and gives students the opportunity to meet and interact with a variety of distinguished biologists.

   1. Biology majors are required to take BIOL 097. BIOL 097 counts as one of the credits required for a major in biology.
   2. Evaluation of a student’s performance for this comprehensive examination will be graded and will be based on the questions prepared by each individual and team for each lecture, participation in discussions, hosting a guest speaker and the final presentation. 
   3. Students who fail BIOL 097 fail the comprehensive exam and thus may not graduate. 
   4. If a student is given permission by the College to be away from campus during the spring semester of the senior year, the Biology Department faculty may give permission to the student to write a senior paper and enroll in BIOL 095, a Senior Project, to satisfy the College requirement of a comprehensive examination. Alternatively, the student may be given permission by the chair of the Biology Department to enroll in Themes in Biology during the junior year if the student has planned in advance to be away during the spring semester of the senior year.

6. NSE breadth courses:  The study of biology relies on concepts and tools from other disciplines in the natural sciences.  In order to strengthen these connections we require that majors take NSE breadth courses that interest them in order to enhance their abilities as broadly trained biologists.  Courses that satisfy the NSE breadth requirement for the Biology major are:  ASTRO 014 or above, CHEM 015 or above, COMP SCI 021 or above, ENGR 005 or above (with the exception of ENGR 007 or ENGR 010), MATH 15 or above (with the exception of MATH 020), PHYS 003 or above (with the exception of PHYS 029), STAT 11 or above, ECON 031 or 035. 

   i. Courses used to meet the Math/Stat criterion for acceptance to the major may not be counted toward the NSE breadth course requirement.  Courses used to meet any other Biology major requirement may not be counted toward this requirement. While a student may test or place out of the Math criterion by AP, IB, or math placement test for acceptance to the Biology major, both NSE breadth courses necessary for the completion of the major must be taken after matriculation at Swarthmore. If a student uses CHEM 038 to satisfy their Group I requirement, it may not be used to satisfy the NSE breadth requirement.  Note: For the Class of 2026 and beyond, CHEM 038 will no longer be accepted towards a Biology major.

Acceptance criteria

1. The course requirements for acceptance to an honors major in biology are the same as those for a course major in biology (see above).
2. Admission to the Honors Program in biology is based on academic record. Applicants to the Honors Program in biology must have a grade point average (GPA) of 3.00 in all courses taken in the Natural Sciences and Engineering Division at Swarthmore College and must obtain a grade of B or better in all lecture courses and seminars used for the Honors Program. Applicants must also have a GPA of 3.00 in all biology courses. Unpublished grades in biology for the first semester of the first year will be considered in these requirements; passing grades of CR in other courses in the Division of Natural Sciences and Engineering are acceptable.
3. Students should list the anticipated fields of study, including two seminar courses, in their Sophomore Plan.
4. Students who are accepted into the program must select a research project and mentor by the middle of the junior year. Final approval of the student’s Honors Program will occur during the fall semester of the senior year when the Final Honors Program Form is signed by the chairs of the participating departments.

Requirements for graduation

1. Credit requirements for honors: Honors biology students must complete a minimum of eight biology credits and fulfill the requirements for an Honors Biology major. Courses taken the first semester of the first year are all CR/NC.  After this semester, only one Biology course with a recorded grade of CR can be used to fulfill the requirements of a Biology honors major.  Seminars (100-139) may not be taken CR/NC. Students must earn a grade of B or better for all courses and seminars used for honors preparations. Honors students may not take Bio 097, Themes in Biology, for credit but are welcome and encouraged to attend the seminars.  SP credits cannot be used to satisfy the eight credit requirement. Note: For the Class of 2026 and beyond: Biology majors, including Honors, will be required to complete 9 biology credits and CHEM 038 will no longer be accepted towards a Biology major.
2. Distribution requirements for honors: Students graduating with an honors major in biology must pass at least one intermediate course in each of the following three groups: I. Cellular and Molecular Biology, II. Organismal Biology, and III. Population Biology. The digit in the tens place of the course number signifies the group of the course (i.e., BIOL 010 is a group I course, BIOL 020 is a Group II course and BIOL 030 is a Group III course).
3. Seminar requirement for honors: All honors biology majors are required to complete at least two seminars (those with a number greater than 100) for honors preparations. A seminar in biology is defined as an advanced offering that uses primary rather than secondary source materials and encourages active student participation in presentation and discussion of materials. Note that all seminars have a prerequisite course from the intermediate level (numbered 010-039); the particular prerequisites for each seminar should be considered during selection of intermediate level courses. The two seminars used for honors preparations must be taken from different faculty members and must be taken at Swarthmore College.  Students must earn a B grade or better in the intermediate course used as the seminar prerequisite to enroll in a seminar.  
4. Research (Thesis) requirement for honors: At least one credit of thesis research (BIOL 180) is required. Additional credits of Honors research (BIOL 180) are permitted, but not required. Thesis research will be graded by an External Examiner. For example, the thesis research may be a substantial project carried out over 2 semesters, 2 summers, or 1 summer + 1 semester.
   1. The primary mentor for the thesis need not be a Swarthmore faculty member, but a Swarthmore faculty member must agree to be an on-campus mentor.
   2. Students should plan on completing their research by the end of the fall semester of their senior year.
   3. The honors thesis has a page limit of 20 pages, not counting references, figures, figure legends or tables.
5. Senior Honors Study: Senior Honors Study (BIOL 199) is required for all honors majors in the spring semester of their senior year. This integrative and interactive program prepares each student to finalize and present his or her thesis work formally, in both oral and written forms. During the first few meetings of the semester, faculty members are available for consultation about data analysis. At mid-semester, students present posters of their projects to the faculty and other honors students for review. Comments from faculty and students on these posters will guide students in revising and polishing their written theses. SHS BIOL 199 is Credit/No Credit and the evaluation is done by the biology faculty.
6. Review of work for honors: The Biology Department will review the academic work of all candidates for the external examination at the end of the junior year and in November of their senior year. Progress on thesis research is assessed at the beginning of the fall semester of the senior year. At these times, the department may ask a candidate to discontinue participation in the Honors Program. Withdrawal from the Honors Program must occur by December 1 of the student’s senior year. At that time, the student is responsible for consulting with the department about satisfying the comprehensive requirement for the major.
7. Honors examinations: Students will take two written examinations, one based on each of their seminar preparations. The biology written examinations will be closed-book, 3-hour exams. The oral exams are normally one-on-one, but there are special circumstances under which a student may be examined by a panel of examiners. Oral examinations for seminar preparations are normally 45 minutes in length. The oral exams for thesis research are 60 minutes in length.
8. NSE breadth course requirement: Biology Honors majors must complete two courses from the following list of courses outside the Biology Department:  ASTR 014 or above, CHEM 015 or above, CPSC 021 or above, ENGR 005 or above (with the exception of ENGR 007 or ENGR 010), MATH 015 or above (With the exception of MATH 020), PHYS 003 or above (with the exception of PHYS 029), STAT 011 or above, ECON 031 or 035.  
   1. Courses used to meet the Math/Stat criterion for acceptance to the major may not also be counted toward the NSE breadth course requirement.  Courses used to meet any other major requirement may not also be counted toward this requirement (CHEM 038 for Group I, for example).  While a student may test of place out of the Math criterion for acceptance to the major, both NSE breadth courses must be taken after matriculation at Swarthmore. Note: For the Class of 2026 and beyond, CHEM 038 will no longer be accepted towards a Biology major.

Biochemistry

The Biology Department, in collaboration with the Chemistry and Biochemistry Department, offers a course major and an honors major in biochemistry. This major gives students the opportunity to gain a strong background in chemistry with special emphasis on the application of chemistry to biological problems. Approval and advising for this special major are obtained through the Chemistry and Biochemistry Department and details about the course and honors major can be found in the Chemistry and Biochemistry section of this catalog. The Biology Department encourages biochemistry majors to take both BIOL 001 and BIOL 002 as a number of intermediate level courses in biology require both courses as a prerequisite.

1. Honors biochemistry majors are expected to participate in Senior Honors Study (BIOL 199) only if the thesis research is done in the Biology Department.
2. Honors biochemistry majors must conduct thesis research with a Swarthmore faculty member.

Neuroscience

The Psychology and Biology departments offer a special major in Neuroscience for course and honors majors that combines work in the two departments in a way that allows students flexibility in choosing the focus of their Neuroscience major.  Approval for this special major is done through both departments.  Each Neuroscience major is assigned a faculty advisor from whichever of the two departments best reflects the focus of that student’s plan of study.  Details about the Neuroscience special major can be found on the Biology website.

Bioeducation

The special major in bioeducation requires six credits in biology.  Most students take BIOL 001 and BIOL 002; a score of 5 on the Biology AP exam or equivalent can substitute for BIOL 001 and/or BIOL 002 and count for 1 credit.  Students must take Evolution (BIOL 034) and at least one intermediate Group I and one intermediate Group II course.  Completion of Chem 010, Math 015 and STAT 011 or placement out of these courses is required.  In addition, the NSE elective requirement can be fulfilled by one of the following:  ASTR 016, CHEM 015 or CHEM 022, CPSC 021 or above, PHYS 003/003L or above (not including PHYS 29 or 95), ENGR 005 or above (with the exception of ENGR 007 or ENGR 010), Math 025 or above.  The special major in Bioeducation will include at least five credits in Educational Studies.  Students should consult with the chair of the Educational Studies Department about specific requirements.  Approval and advising for this special major are through the Biology and Educational Studies Departments.  

Environmental Studies

A minor in environmental studies consists of an integrated program of five courses plus a capstone seminar (ENVS 091), which a student takes in addition to a regular major. The details of the minor and courses offered may be found at www.swarthmore.edu/envs.xml. The five courses must include at least one course in environmental science/technology; at least one course in environmental social science/humanities; and at least one more course from either of these two groups for a minimum of three courses from these two lists. Up to two of the five required courses may be chosen from the list designated adjunct and interdisciplinary courses. The capstone seminar is offered in the spring of the student’s senior year. Advising for this program is by the chair of the Environmental Studies Committee.

Other special majors

Individualized special majors may be constructed after consultation with the chairs and approval of the participating departments. The special major is expected to specify a field of learning that crosses departmental boundaries and can be treated as a sub-field within the normal departmental major. Individualized special majors consist of at least 10 credits, but usually not more than 12. A more detailed explanation of the individualized special major is found in Chapter 7 “Educational Program .” Previously approved special majors include cognitive science, neuroscience, environmental science, biostatistics and biophysics.

Academic year opportunities

Summer opportunities

Graduate school

Many of our majors have gone on to graduate school in biology after completion of their degree. While some students attend graduate school immediately after graduation from Swarthmore, others work for at least a year or two before applying to graduate programs. This time between finishing at Swarthmore and graduate school can be used to gain more experience in biology, or to try out a new field. These experiences both strengthen your graduate school applications and help you to know what you are most interested in studying. One- or two-year jobs are available at a variety of research institutes, field stations, universities, museums, government laboratories and companies. The Department maintains an informal list of opportunities on the Biology website.

The Biology Department faculty are happy to talk with students about graduate programs and projects. Note that graduate schools in biology pay Ph.D. students a stipend for research and/or teaching. In addition, a few prestigious fellowships (e.g., National Science Foundation Graduate Research Fellowship) are awarded to the student (not to the program), giving the recipient more flexibility and autonomy in their graduate program.

Career options/opportunities

In addition to graduate school and professional school (medical, law, veterinary, business) there are many other job possibilities. The American Institute of Biological Sciences web page (www.aibs.org/careers/), which describes jobs open to people with a degree in biology, is a helpful resource. A degree in biology can lead to positions in the following areas:

Research: This could include laboratory work, fieldwork, or some combination of the two. Major employers include universities, research institutes, non-government organizations and companies (e.g., pharmaceutical, agricultural, biotechnology, food science).

Healthcare: Many doctors, dentists, nurses, veterinarians, laboratory technicians and other health care providers have backgrounds in the biological sciences. Other biologists utilize their background in disease prevention and control.

Environmental management: Park rangers, conservation biologists, zoo biologists, and land management specialists use their background in biology to develop and evaluate management plans to conserve natural resources.

Education: In addition to serving as university and college professors, some of our graduates teach in elementary and secondary schools, at museums and zoos, and at aquaria and nature centers. Biology majors also author newspaper and magazine articles, and may contribute to textbooks as writers, editors or illustrators.

Other ideas: Our graduates have obtained jobs in politics and policy, in areas such as economic and biological impacts of land use practices, science advising on biomedical procedures, effects of climate change, and educating members of Congress about scientific issues. Other biology majors have found positions in forensics, bioinformatics and computational biology. Finally, some majors have had careers in investment banking, consulting and law.

General Studies

• BIOL 001. Cellular and Molecular Biology
• BIOL 001SP. Cellular and Molecular Biology
• BIOL 002. Organismal and Population Biology
• BIOL 002SP. Organismal and Population Biology
• BIOL 004. First Year Seminar: Making Earth: How Plants & Soils Transform Our Planet
• BIOL 005. First Year Seminar - Exploring Regeneration & Cancer Biology Through Authentic Research.
• BIOL 008. First Year Seminar: Containing Multitudes
• BIOL 009. Our Food

Group I: Intermediate Cellular and Molecular Biology (010-019)

• BIOL 010. Genetics
• BIOL 013. Stem Cell Biology
• BIOL 014. Cell Biology
• BIOL 016. Microbiology
• BIOL 017. Microbial Pathogenesis and the Immune Response
• BIOL 019. Omics

Group II: Intermediate Organismal Biology (020-029)

• BIOL 020. Animal Physiology
• BIOL 021. Neuroethology
• BIOL 022. Neurobiology
• BIOL 024. Developmental Biology
• BIOL 025. Plant Biology
• BIOL 027. Systems Biology
• BIOL 028. Global Change Biology
• BIOL 029. Developmental Neurobiology

Group III: Intermediate Population Biology (030-039)

• BIOL 030. Animal Behavior
• BIOL 031. Marine Mammal Biology and Conservation
• BIOL 032. Animal Biodiversity.
• BIOL 034. Evolution
• BIOL 036. Ecology
• BIOL 037. Conservation Biology
• BIOL 039. Marine Biology

Group IV: (040-049)

• BIOL 040. Astrobiology
• BIOL 041. Ecology, Evolution and Development
• BIOL 042. Climate Change Science and Communication
• BIOL 043. Introduction to Python for Biologists.
• BIOL 068. Bioinformatics

Independent Studies

• BIOL 093. Directed Reading
• BIOL 094. Research Project
• BIOL 094A. Research Project: Departmental Evaluation
• BIOL 098. Neuroscience Thesis
• BIOL 180. Honors Research

Senior Comprehensive Examination

• BIOL 095. Senior Project
• BIOL 097. Themes in Biology

Honors Study

• BIOL 199. Senior Honors Study

Group I, II, and III Seminars

• BIOL 111. Genome Regulation by Noncoding RNA
• BIOL 113. Stem Cells in Development and Regeneration
• BIOL 114. Symbiotic Interactions
• BIOL 115E. Plant Molecular Genetics and Biotechnology
• BIOL 116. Microbial Processes and Biotechnology
• BIOL 117. Trends in Pharmacology
• BIOL 119. Genomics and Systems Biology
• BIOL 120. Physiological Ecology.
• BIOL 121. Neural Systems and Behavior.
• BIOL 122. Reverse Engineering the Brain
• BIOL 123A. Neurobiology Seminar
• BIOL 125. The Cellular Basis of Embryonic Development and Cancer
• BIOL 126. Biomechanics in Development and Regeneration
• BIOL 127. Behavioral Neuroendocrinology
• BIOL 128. Evolution and Development
• BIOL 129. Developmental Neurotoxicology
• BIOL 130. Animal Reproduction.
• BIOL 131. Animal Communication
• BIOL 132. Wildlife Conservation
• BIOL 134. Evolution of Animal Societies
• BIOL 136. Molecular Ecology and Evolution
• BIOL 137. Biodiversity and Ecosystem Functioning
• BIOL 139. Global Ocean Change Biology