Harvard University offers graduate instruction in several areas of biology. The members of the Department of Organismic and Evolutionary Biology (OEB) share a common interest in understanding the structure, function, and variation of biological systems.

The research interests of the OEB faculty include the flow of energy and material through ecosystems, the development and structure of communities and populations, the diversity of plant, animal, and microbial groups, and the mechanisms that have permitted diversity to evolve. These studies span a wide range of spatial and temporal scales and include many different levels of biological organization.

A variety of theoretical, descriptive, and experimental approaches are used in the laboratory and field studies carried out by members of OEB. We have representation in anatomy, behavior, biogeochemistry, development, functional morphology, physiology, paleontology, population genetics, molecular evolution, systematics, and the biology of global change.

The Harvard University Herbaria and the Museum of Comparative Zoology (MCZ) house essential libraries, extensive natural history collections, and experimental laboratories that are utilized by faculty and students of the department. Other resources include the Concord Field Station of the MCZ, the Harvard Forest, and the Arnold Arboretum.


We require online submission of the application.

Completed applications should be received by December 1 in order to be considered for admission for the coming year.

Although Harvard University awards both the AM and the PhD degrees in biology, the department will recommend for admission only candidates for the PhD degree.

Applicants should have the equivalent of seven full (two-term) courses in the fields of biology, chemistry, physics, mathematics, computer science, or geology; at least a third must be intermediate-level courses. GRE General scores are required. GRE subject scores are recommended. Foreign students should have, recent TOEFL IBT scores of at least 80, or hold a degree from an institution at which English is the language of instruction.

Financial Aid

The department has available financial support based both on merit and need. Ordinarily, students who are accepted into the program receive substantial financial aid. Stipends are typically composed of scholarships, teaching fellowships, and research assistantships. Ordinarily, the department does not provide scholarship or fellowship support beyond a period of six years.

Applicants are expected to seek fellowship support from sources outside the University. US citizens who have received fewer than 30 graduate-level credits are expected to apply for pre-doctoral fellowship opportunities provided by the National Science Foundation (NSF). Applications for NSF fellowships are typically due in the fall, and applicants may find application materials at www.nsf.gov.

Doctor of Philosophy (PhD)

A departmental Graduate Committee is responsible for all matters pertaining to OEB graduate students. It considers applicants for admission and approves all examination committees appointed for doctoral candidates.

Course selection (other than those prescribed; see Prescriptions) is determined by consultation between the advisor and student. During the first two years, satisfactory progress towards the degree requires fulfillment of the departmental teaching requirement, successful completion of at least 16 half-courses (with no more than 12 of these half-courses at the 300 level), completion of all prescribed courses with a grade of B- or better, and passing the qualifying examination (which should be held no later than the end of the second year). Thereafter, satisfactory progress is assessed by the student’s Dissertation Committee at an annual Dissertation Conference.

Academic Residence Requirements: A minimum of two years of full-time study is required to fulfill the residence requirements (16 half-courses passed with distinction). Research (300) courses taken under the direction of members of the Harvard faculty count toward fulfilling the academic requirements. These courses ordinarily require a minimum of ten hours per week (one-quarter TIME) for a minimum of a term. Full-time research (recognized as TIME by the Registrar) will generally not be accepted by the department as part of the academic requirement for a degree.

Research Advisor: Upon admission students will be assigned a faculty member in the department to serve as a dissertation research advisor. Students are encouraged to consult freely with any staff member on matters pertaining to their programs and may change to another advisor at any time, subject to the approval of the new advisor and the chair of the Graduate Committee and notification of the department office.

Students must have an advisor at all times and it is the student’s responsibility to ensure this. Any student who does not have an advisor at the beginning of a term must withdraw from the department at the end of that term if arrangements for a new advisor have not been made by that time.

Prescriptions: These courses are personalized to ensure that we all have a strong, well-rounded academic background. Upon your arrival, expect to receive a tentative list of courses which have been determined by the Prescription Committee. These courses must be completed with a  grade of B- or better prior to a student’s qualifying examination.  Regardless of prescriptions, each student must take at least four graded half courses prior to graduation.

Each student should confer with his/her advisor to

1. determine if there are any courses on the tentative list which may not be necessary and 
2. prepare a tentative course of study beyond the required prescription courses. 

If all is in agreement with the list you receive, it is not necessary to meet with the Prescription committee. However, if you would like to petition for a change, you will meet with the committee to make your request. Based on your prior training, an appropriate course of study will then be decided.

  • The Committee will require you to meet the content of the following Harvard courses before your Qualifying Examination:
  • Mathematics - college-level calculus
  • Statistics;
  • A reasonable combination of courses in cell biology, molecular biology, genetics, and evolutionary biology;
  • 'Kingdom' course - A course that deals with the systematics, structure, function and ecology of at least one major group of animals or plants (e.g., OEB xx, xx).

Teaching Requirement: The department has a two semester teaching requirement for completion of the degree. Most will fulfill this requirement in Year 2 and Year 4, since part of the annual stipend in those years is tied to this teaching service. Teaching in years 1 is not allowed and in year 3 will only be allowed with the approval of the Graduate Committee. . The department guarantees six semesters of support by way of teaching; in the absence of external funding, most students teach both semesters in their fifth and sixth years. No support is guaranteed beyond the sixth year; occasionally, students take longer than six years to complete their degrees and in some cases, such students are able to obtain teaching positions either within OEB or from other departments.

Admission to Candidacy for the PhD Degree: After completion of 16 graded half-courses in biology and related subjects (300 level courses are included), the student’s record is reviewed by the Graduate Committee. Favorable action will provisionally admit the student to candidacy for the PhD degree. Final admission to candidacy is by means of the qualifying examination.

Qualifying Examination: This is an oral examination which should be taken before the end of the second year of graduate study or prior to the completion of sixteen half-courses. Prescriptions must be satisfied prior to the examination, i.e. course completed with a grade of B- or better. Exceptions may be made by petition to the Graduate Committee.

The goal of the Qualifying Examination is to assess whether the student can present a well-designed research framework for her/his dissertation, and to examine the student’s knowledge of broad areas of knowledge. Students should look upon the Qualifying Examination as the last time in their academic career in which they will be asked to review what they know, and to synthesize and integrate their knowledge of organismal and evolutionary biology. As such, it is an opportunity to learn and review; after this point, students will be focused on their particular area of research and may not again have the opportunity to think widely for many years.

The Qualifying Examination Committee will consist of the student's advisor acting as Chairman, plus at least three additional individuals. At least two of the additional members must be members of the OEB faculty. The overall composition of the Examination Committee must be approved by the Chairman of the Graduate Committee before a student submits the Qualifying Exam notice to the Graduate Office.

The student should arrange an examination time by contacting committee members. Three hours should be allotted for the meeting, though examinations often are shorter in duration. Students should be aware that many faculty are not available to participate in examinations when school is not in session. Students are advised to remind faculty of the time and place of the meeting several days before the examination. 

During the exam students will be tested on three broad topics pertinent to, but not restricted to, the specific topic of the proposed or ongoing dissertation studies. Topics should overlap little and should be broad in scope. For each topic a syllabus outline for a course covering the topic should be prepared. This will serve as a guide for the Committee members to begin asking questions, though committee members are not limited to asking questions directly relevant to the syllabi. Many students meet with committee members prior to the examination to discuss what sorts of questions might be asked and to receive advice and recommendations on specific material which may be worth reviewing. There are no set guidelines on syllabus format; they should be modeled after those commonly distributed at the beginning of OEB courses. Students should consult with their advisors on exact format.

In addition, the student will be expected to prepare a written thesis research proposal for the Qualifying Exam Committee. There is no set format for the proposal, but the guidelines for NSF Dissertation Improvement Grants are one often followed format. Students should consult with their advisor about format. In the examination, students will present a brief oral presentation on the proposal, lasting no more than 15-20 minutes, not counting questions (recalling that committee members will have read the proposal, so that it is neither necessary nor desirable to review everything in it). 

The syllabi and thesis proposal must be distributed to committee members no less than two weeks prior to the examination, as well as to the graduate program coordinator. Failure to do so will result in postponement of the examination. Materials may be distributed electronically, but when doing so, the student should inquire whether any committee members would prefer to receive hard copies.

The Committee Chairman (the advisor) will be in charge of the examination. At the outset, the student will be asked to leave the room so that the committee can discuss the student’s progress to date and to review the courses prescribed and confirm that they have been taken. The student will then make her/his oral presentation, after which committee members will ask questions. Usually, committee members take turns, each asking several questions, with several rounds of such questioning. It is up to the Chairman whether he/she wishes to ask questions or simply moderate the proceedings.

At the end of the examination, students will again be asked to leave the room. Students should not be concerned if the committee discussion takes more than a few minutes—sometimes committee members get off track and are discussing issues other than the student’s performance.

After the exam, students who passed the Qualifying Examination shall be promptly notified and approved for continuation of dissertation studies and advancement to Doctoral Candidacy. At least one term should ordinarily elapse between the qualifying exam and when the Thesis Examination can be held. The Committee may pass the student, but prescribe additional coursework or other additional work (such as writing a review paper on a particular topic).

If the Qualifying Examination reveals serious deficiencies, the committee may require: (1) that the student be reexamined at a later date, or (2) that the student not be admitted to candidacy for the doctoral degree. In the latter case, the student subsequently will be orally examined by one or more faculty members designated by the committee and a judgment rendered.

If the committee finds the student lacking the necessary qualifications to continue the Ph.D. degree, it will recommend that further candidacy be terminated not later than the end of the ongoing academic year. The recommendation to terminate must be reviewed and approved by the Graduate Committee and by all OEB faculty members. The student, together with the advisor, may appeal any such decision by submitting to the Graduate Committee written arguments for a reversal of the decision to terminate. Under such circumstances, the case will be further reviewed by the Graduate Committee as well as by the Department and a final decision rendered.

Dissertation Conference: In the Thesis Conference, students have a relatively early opportunity to review with their advisor and the Thesis Conference Committee the thesis project, its progress and future potential. The first Thesis Conference should be held no later than one year after the Qualifying Examination and at one year intervals thereafter. The student should present orally a brief account of any results obtained and plans for additional research. The Committee should indicate to the student whether it anticipates that the thesis will be acceptable. It should also suggest improvement where needed. The conference is not intended to be an oral "examination,” but the committee must approve of the student’s progress and plans. If the committee does not approve, then the student will be considered not to be making “Satisfactory Progress” and a plan must be prepared to return to good standing within six months. Failure to do so may lead the Committee to recommend dismissal from the graduate program. Students more than six months late in holding a committee meeting will automatically be considered to not be making Satisfactory Progress.   

The Thesis Conference Committee will consist of the student's advisor, who will serve as chairman, and at least—but not limited to—two other members. At least three of the members of the committee must be faculty members of the Department of Organismic and Evolutionary Biology. Additional members affiliated with other departments or institutions may be added after consultation with the advisor. The overall composition of the committee must be approved by the Chairman of the Graduate Committee. It is presumed that this committee will also constitute the Thesis Examination Committee. In some situations, it may not be possible to schedule a meeting at which all committee members can attend. With permission of the advisor and the Chairman of the Graduate Committee, one member may be absent from the meeting, as long as arrangements are made for the student to meet separately with that committee member.

All graduate students in the Department of Organismic and Evolutionary Biology come under the jurisdiction of the Departmental Committee on Graduate Students and Studies. The Chairman of the Committee is authorized to approve all examination committees appointed for doctoral candidates.

1. Application for the Ph.D. Degree
Applications are available in the Departmental Office. Candidates for the degree must file degree applications with the OEB Office by August 15 for award in November; by December 3 for award the following March; and by April 1 for award at Commencement. Check the Academic Calendar for updated deadline information. All applications must be approved by the Chairman of the Department. Students should be aware that many committee members are not available for thesis defenses when school is not in session.

2. Thesis Presentation
The student must present the subject matter of the thesis in a seminar before a group open to the general biological community within the University, and to which the members of the Thesis Examination Committee have been invited. This presentation shall take place prior to the Thesis Examination. The Departmental Office should be notified of the Public Presentation one month prior to the date, so that a Thesis Seminar Notice can be sent to the OEB faculty members and fellow students. A copy of the posted notice of the seminar will become part of the student's record.

3. Thesis Summary
Each Ph.D. candidate will prepare a summary of the thesis, ordinarily limited to one page, single-spaced, and submit it to the Departmental Office two weeks prior to the date of the Thesis Examination. Copies of the Thesis Summary will be distributed to all OEB faculty members. This is the ABSTRACT of your thesis.

4. Thesis Examination
The thesis is written under the supervision of the student's research advisor and should conform to the standards outlined in the booklet, "The Form of the Doctoral Thesis," available in the Departmental Office.

The Thesis Examination Committee will consist of the student's advisor who will serve as chairman, and at least two other members suggested by the advisor. At least three members of the committee must be members of the Department of Organismic and Evolutionary Biology. Additional members affiliated with other departments or institutions may be added by the advisor. The overall composition of the committee must be approved by the Chairman of the Graduate Committee. The Thesis Examination Committee will, if possible, be the same as the Thesis Conference Committee.

The OEB Departmental Office and the Chairman of the Graduate Committee must be notified of the time and location of the Thesis Examination two weeks prior to the date desired. At the same time, the candidate will present to his/her Thesis Committee a copies of the thesis in final form (not yet bound; students should  ask committee members whether they prefer digital or hard copies). An additional digital thesis copy must be submitted to the Graduate Office two weeks prior to the Thesis Examination (this copy will be made available to OEB faculty). A copy of the Thesis Examination Notice and the Thesis Summary will be sent to all OEB Faculty members. Failure to provide copies of the thesis to the committee and to the OEB office two weeks prior to the exam date will automatically lead to postponement of the thesis defense.

The student should observe the final dates for holding the thesis examination indicated in the Academic Calendar sent to all students at the beginning of each term. It is suggested that the thesis examination be held at least one month prior to the date the thesis is due in the registrar's office, to allow time for revisions; students should not expect committee members to approve a thesis simply because a student has an impending deadline. 

After examination, the committee will decide whether the candidate will pass, fail, or pass on the condition that specified changes be made to the thesis (because students are often required to do additional work before the thesis is passed, students should defend at least a month before degree filing or other deadlines). The committee may delegate to its chairman the responsibility for seeing that such changes are made in a satisfactory manner before the award of the degree is recommended to the Department by the Committee on Graduate Students and Studies. The student's advisor should make such certification in writing to the Chairman of the Graduate Committee.

If at all possible, students should schedule their last Thesis Conference 1-3 months prior to their thesis defense. At this time, they should review the thesis fully, giving committee members the opportunity to identify issues that should be rectified prior to presentation of the thesis. Holding such a Thesis Conference is the best way to ensure that problems are identified prior to the defense, thus minimizing the chance that the committee will require substantial additional work that may greatly delay awarding of the degree.

In rare cases, it may be possible to hold the Thesis Exam with one committee member absent. Arrangements must be made for that committee member to confer with the advisor prior to the thesis being approved.  Approval for such an arrangement must come from the Chairman of the Graduate Committee and only will be granted under unusual circumstances.

5. Filing the Thesis
Students should consult the GSAS thesis submission guidelines at http://www.gsas.harvard.edu/publications/form_of_the_phd_dissertation.php. Each candidate must be registered in GSAS, paying at a minimum a charge equal to the Facilities Fee, at the time the thesis is filed. These dates may vary and should be checked in the GSAS Handbook available at registration each year. It is the student's responsibility to submit the thesis to the Registrar's Office in accordance with the desired graduation date deadline. The student should also submit a bound copy of the thesis to the OEB Graduate Program Coordinator.

Master of Arts (AM)

The Department of Organismic and Evolutionary Biology does not admit students whose sole purpose is to study for the Master of Arts degree. However, graduate students admitted to any PhD program at Harvard University may apply for the AM degree if they fulfill the following requirements: 

  1. Six graded half-courses in the Department (or courses from other departments approved by the Director of Graduate Studies), with no grades lower than B- and an overall grade average of B or better.
  2. At least three of the six courses must be below the 200 level.
  3. At least two of the six courses must be at the 200 level.
  4. TIME and 300-level courses will not ordinarily be accepted toward the AM degree.
  5. AM candidates must submit a written paper based on original research conducted under the guidance of a faculty member in the department.

Participating Faculty