Transcript Lecture 1
Bioe 109 Evolution Summer 2009 Bioe 109 Evolution Summer 2009 Prerequisites: Bio 20A, 20B, 20C, and Bio 105 (Genetics) Bioe 109 Evolution Summer 2009 Prerequisites: Bio 20A, 20B, 20C, and Bio 105 (Genetics) Textbook: Evolutionary Analysis, 4th Edition by Scott Freeman and Jon C. Herron. Bioe 109 Evolution Summer 2009 Prerequisites: Bio 20A, 20B, 20C, and Bio 105 (Genetics) Textbook: Evolutionary Analysis, 4th Edition by Scott Freeman and Jon C. Herron. Web sites: For textbook: http://wps.prenhall.com/esm_freeman_evol_4/ For class: http://bio.classes.ucsc.edu/bioe109/ Instructors Dhanashree Paranjpe (Dhanu) ([email protected]) Office hours: Monday and Thursday 11am-12noon EMS D450 Teaching Assistants April Bird ([email protected]) Overview of Grading System Assignments: 30% Midterm exam (12th Feb): 35% Final exam (28th August): 35% Assignments There will be 2 assignments worth total 15 pts. Academic Integrity Academic misconduct includes but is not limited to cheating, fabrication, plagiarism, or facilitating academic dishonesty. Everything you turn in must be your own expression of your understanding of the material. Academic misconduct in any part of the course may lead to failing the particular assignment and the course, and may result in disciplinary sanctions Please see: http://www.ucsc.edu/academics/academic_integrity/un dergraduate_students/ Scope and outline of the course • Focus of this course is “conceptual” understanding of evolutionary biology. • All facets of evolutionary biology will be covered. • We will closely follow textbook chapters, however it is NOT a review of material covered in textbook. • Examples from all taxa (plants, animals, fungi, bacteria) will be used to explain and elaborate various concepts. REMEMBER: this field is ripe with controversies and uncertainty unlike other fields of biology. But we are here to learn and have fun in the process! Bioe 109 Evolution Summer 2009 What is Evolution? What is Evolution? - in general usage “evolution” = “change”. - origin from Latin “evolvere” meaning to “unfold or disclose”. - first biological use of “evolution” was by embryologists in the 18th century (e.g., Haller, Bonnet). Definition 1 (from Ernst Mayr): “change in a population over time of the proportions of individual organisms that differ in one, or more, genetically-determined traits”. Definition 2 (from Theodosius Dobzhanksy): “the transformation of genetic variation originally present within populations into variation between populations in both space and time”. Evolution – fact or theory? Evolution – fact or theory? - the term “theory” has very a different meaning in colloquial speech than in science. Evolution – fact or theory? - the term “theory” has very a different meaning in colloquial speech than in science. Colloquial or everyday speech: “conjecture” or “speculation” (e.g., my pet theory for…) Evolution – fact or theory? - the term “theory” has very a different meaning in colloquial speech than in science. Colloquial or everyday speech: “conjecture” or “speculation” (e.g., my pet theory for…) Science: “a logical construct of facts, hypotheses and laws that explains an observed or known phenomenon” Examples of scientific theories: ● Heliocentric theory ● Big Bang theory ● Atom theory ● Giant impact theory ● Quantum theory ● Plate tectonic theory ● Special theory of relativity ● Cell theory ● The theory of evolution Evolution – fact or “just” a theory? http://www.pbs.org/wgbh/evolution/educators/teachstuds/svideos.html Public acceptance of evolution Public acceptance of evolution Is the following statement true, false, or are not sure or don’t know? “Human beings, as we know them, developed from earlier species of animals”. See Miller et al. 2006, Science 313: 765. Additional reading material about the ongoing debate on teaching evolution in school curricula is uploaded on class website Scott (1997) and Pennock (2003). How does the study of evolution differ from other areas of biology? How does the study of evolution differ from other areas of biology? 1. Method of study: inference based on the “comparative” versus “experimental” method. How does the study of evolution differ from other areas of biology? 1. Method of study: inference based on the “comparative” versus “experimental” method. - evolutionary biologists commonly use the hypotheticodeductive method. How does the study of evolution differ from other areas of biology? 1. Method of study: inference based on the “comparative” versus “experimental” method. -evolutionary biologists commonly use the hypotheticodeductive method. Facts/ observations Formulate hypotheses Test hypotheses by additional data Accept/ modify/ reject the hypothesis How does the study of evolution differ from other areas of biology? 2. Types of questions asked: “proximate” versus “ultimate” causations (Mayr 1961). How does the study of evolution differ from other areas of biology? 2. Types of questions asked: “proximate” versus “ultimate” causations (Mayr 1961). -“functional biologists” (e.g., physiologists, molecular biologists, etc.) ask “proximate” questions. How does the study of evolution differ from other areas of biology? 2. Types of questions asked: “proximate” versus “ultimate” causations (Mayr 1961). - “functional biologists” (e.g., physiologists, molecular biologists, etc.) ask “proximate” questions. - these questions usually begin with “how”. How does the study of evolution differ from other areas of biology? 2. Types of questions asked: “proximate” versus “ultimate” causations (Mayr 1961). - “functional biologists” (e.g., physiologists, molecular biologists, etc.) ask “proximate” questions. - these questions usually begin with “how”. - evolutionary biologists ask “ultimate” questions. How does the study of evolution differ from other areas of biology? 2. Types of questions asked: “proximate” versus “ultimate” causations (Mayr 1961). - “functional biologists” (e.g., physiologists, molecular biologists, etc.) ask “proximate” questions. - these questions usually begin with “how”. - evolutionary biologists ask “ultimate” questions. - these questions usually begin with “why”. Objectives of the Course Objectives of the Course 1. To foster “evolutionary thinking”. Objectives of the Course 1. To foster “evolutionary thinking”. 2. To foster an understanding of organisms in the context of their evolutionary histories. Objectives of the Course 1. To foster “evolutionary thinking”. 2. To foster an understanding of organisms in the context of their evolutionary histories. 3. To realize the potential and the limits of evolutionary change within species. Objectives of the Course 1. To foster “evolutionary thinking”. 2. To foster an understanding of organisms in the context of their evolutionary histories. 3. To realize the potential and the limits of evolutionary change within species. 4. To appreciate that, like a tinkerer, evolution has no ultimate goal in mind. Macroevolution Evolution of groups larger than species Vs. Microevolution Changes in gene frequency within a population from generation to generation Courtesy “ Understanding Evolution” (http://evolution.berkeley.edu/evolibrary/) Macroevolution Evolutionary change seen over 10’s to 100’s of millions of years Vs. Microevolution Evolution at this scale can be observed over relatively short periods of time ………..A continuum Mutation Gene Flow Genetic drift Natural selection 3.8 billion years