The Extinction Vortex
Tuesday Week 8

Announcements:

 

 


Tuesday - Question of the Day: Who gets hit first by extinction?

Objectives:

 

Powerpoint - "The Extinction Vortex"

 

 

 

 

 


The following notes augment/duplicate the notes in the Powerpoint slides:

 Question 1: Explanation

What are "background" extinction rates for various groups of species?

source - http://www.enchantedlearning.com/subjects/dinosaurs/extinction/

 


Question 2:

What makes species susceptible to extinction?

Wilson lists several causes of rarity, but all are ultimately linked to small population size.

What are three ways in which a species can be rare?

 


 Question 2:

What makes species susceptible to extinction?

Wilson lists several causes of rarity:

 

 


Question 3:

What are the hazards of small population size?

Activity with M&M's

 

 


Question 3:

What are the hazards of small population size?

 

The previous example shows what can happen to variation in a population when it is small.  But how do populations get to be small in the first place?  And what impact might that have on genetic diversity?

 

 

 



Question 3:

What are the hazards of small population size?


Question 3:

What are the hazards of small population size?

The combination of all of the above factors leads to -

The "Extinction Vortex"

 

 

 

 

 


Question 4:

Begin pondering this moral dilemma: when should we humans become involved in saving rare species?