Class 10, October 28:

 

Complete the assignments below and use Piazza (https://piazza.com/cornell/fall2015/bionb4200/home) to answer thought questions (due Tuesday Oct 27 before midnight). We will discuss your answers to these questions in class:

 

 

Sexual selection and acoustic signals.

 

Learning outcomes:

 

  1. You will be able to explain the concept of sexual selection and how it operates.

 

  1. You wil be able to compare and contrast the two primary mechanisms of sexual selection and identify the kinds of signal traits that are likely to evolve as a result of each mechanism.

 

At the end of our last class meeting we discussed the different components that make an individual have high “fitness” or reproductive success and we reviewed this diagram:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As you can see here, natural selection selects for traits that increase an individual’s fitness/total reproductive success. There are two components of fitness: more fit individuals have traits that allow them to survive and have a long lifespan. Fit individuals also have high reproductive success and are able to successfully obtain matings and have many offspring. Traits that increase an individual’s ability to obtain matings are sexually selected traits.

 

To prepare you for our field trip and unit on sexual selection:

 

1. Watch the video linked below:

 

http://ed.ted.com/on/JLk7NshX

 

2. Read this excerpt from Bradbury and Vehrencamp:

 

 

 

 

 

3. Read this paper. Carefully read the abstract, introduction and discussion, you can skim through the rest: