Lecture25_handout_24 and 26Oct11

Lecture25_handout_24 and 26Oct11 - BioEE 1780 Evolution and...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
BioEE 1780 Fall 2011 Evolution and Diversity Today’s lecturer: Irby Lovette October 24 and 26 (same handout both days) Speciation: What are species and where do they come from? Readings : textbook chapter 16; discussion section materials for hybridization lab exercise. See the detailed reading guide at the end of this handout for more information on how these lectures link to the textbook. Reminder : these two lectures conclude the lecture material that will be covered on the second prelim on November 7th. That prelim will cover the most recent three biodiversity lectures, all of the population genetics lectures, these two speciation lectures, and the section activities associated with those modules (including the hybrid zone activity). The material presented in the forthcoming lectures given by Mike Webster will be covered on the 3rd prelim at the end of the semester. The next two lectures are on the general topic of speciation. We will start by discussion how species arise and how we define them using a variety of criteria. We will then go into more detail important facets of the speciation process. Hybridization comes up in a number of contexts in these lectures, as it provides a window onto the process of speciation — and because you will be exploring the biology of hybrid zones in a section activity. Study goals from these two lectures on speciation: You should understand the three species concepts and their similarities and differences, not only by memorizing their definitions and criteria but also by understanding (1) when and why these different species concepts are used by biologists, and (2) when and why they might lead to different classifications of species. You should also be very familiar with how primary and secondary hybrid zones form, how they are different, and what you would expect to see if you sampled traits across them (just as you will do in the butterfly/flicker lab in section). You should understand the potential role of geography (allopatry, parapatry, sympatry) in speciation, including the different steps in the classical allopatric speciation model. You should understand the distinction between vicariance and dispersal, between intrinsic and extrinsic barriers to reproduction, and the potential role of ecology/natural selection in speciation. Make sure that you understand the concept of ‘reinforcement’ and why it is important in the context of speciation. Most importantly of all, I want you to be able to step back from the details and see how history, geography, genetic drift, and natural selection can all combine in various ways to influence the process of speciation. These linkages are outlined in a flow chart that appears several times in the powerpoints, but it is not sufficient just to memorize that schematic diagram: you need to understand the linkages that it represents. Speciation, Part I
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 7

Lecture25_handout_24 and 26Oct11 - BioEE 1780 Evolution and...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online