Biology 425

BIOL 425

Catalog Entry

Biology 425. Evolution
Three hours lecture (3).

Prerequisite: A grade of "C" or better in BIOL 131, BIOL 132,  BIOL 231, and BIOL 232.

Semester offered: Every Spring

Introduction to modern hypotheses on the mechanisms of genetic change in populations, speciation, evolution of societies, origins of higher taxa, causes of extinctions and modern approaches to classification. Concepts will be applied to a discussion of human evolution. 


Detailed Description of Content of Course

This course provides the theoretical underpinning of biology which is necessary for any modern biologist to understand. Other department offerings describe when various plant and animal taxa arose and went extinct; this course discusses the possible mechanisms that cause origin and extinction of taxa.

Major topics include:


1. History of evolutionary thought.
2. Evidence that life on earth has changed.
3. Mechanisms of change at the population level, including mutation pressure, genetic drift, gene flow, and natural selection.
4. Mechanisms of speciation, including various allopatric and sympatric models.
5. Origin of complex adaptations.
6. Theories of precambrian evolution.
7. An overview of phanerozoic evolution with analysis of debates over issues such as punctuated equilibrium, warm-blooded dinosaurs, the K/T extinction, evolution of bird flight, etc.
8. Human evolution.
9. Evolution of social behavior.


Detailed Description of Conduct of Course

Classes are a mixture of lecture and discussion. Lectures are periodically interrupted for student writing or problem solving. For discussion periods, students bring their analyses of readings to class, get reactions and help from their peers, then after class revise their analyses. The instructor provides supplementary information and questions to guide student reading and facilitates small group and whole class discussions by questioning, clarifying, and helping students summarize their ideas.

A series of papers result from these discussions. Often the thrust of the work is to understand the author's point or hypothesis, his evidence to support it, and assumptions contained in the argument. Later in the semester students may be asked to do that kind of analysis on two papers with opposing hypotheses and then evaluate which hypothesis is best supported. This analysis of scientific arguments is essential training for future scientists.

Students are assigned reading from a textbook as well as the supplementary readings for the discussions. They are generally not told the "correct answer" or given the instructor's interpretation. It is important that future professionals develop responsibility for their own reading. Students are tested on their understanding of textbook information and papers are evaluated on the basis of how fully, accurately, and reasonably positions are justified.


Goals and Objectives of the Course

On completing this course students should be able to:


1. Outline the historical development of evolutionary ideas
2. discuss current concepts and debated issues in evolutionary theory
3. explain with examples how historical hypotheses are scientifically tested
4. analyze scientific arguments and evaluate hypotheses.


Assessment Measures

Graded assignments include examinations that largely through essays and short answers test knowledge of concepts, terms, history, evidence, arguments, etc., and ability to solve population genetics problems and interpret graphs. A series of short papers test ability to apply course information and analyze/evaluate scientific arguments. Both examinations and papers assess understanding of methods of testing historical hypotheses. Students may also be evaluated on their contributions to discussions.


Other Course Information

Computer programs of population genetics may be used to give practice manipulating parameters to see differing results. Students summarize their findings in a report.


Review and Approval

September 2001 Dr. Charles M. Neal, Chair