1. Formation of Species
Speciation

2. Define the following:
Gene pool
Gene flow
Genetic drift

3. The concept of species
New species are discovered and others become extinct
Existing species are essentially changed versions of older species

4. What is a species? A single kind of organism
Morphologically similar (look alike)
Can interbreed to produce fully fertile offspring

5. Speciation
Speciation is the process of when a new species is formed = species formation

6. How do species give rise to other different species?
Speciation begins with isolation
Results when two interbreeding populations stop breeding

7. Isolation: Two Types 1. Geographic Isolation
when a physical separation of the members of a population occurs
Original habitat becomes divided

8. Geographic Isolation Barriers can be formed by:
Canons, mountain ranges, bodies of water, or other features organisms can not cross

9. Allopatric Speciation
A result of geographic isolation
Gene pool begins to differ because of genetic drift and natural selection

10. Isolation: Two Types 2. Reproductive Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                
Isolation: Two Types
2. Reproductive Isolation
Results from barriers to successfully breed between populations in the same area
Organisms begin to diverge

11. Reproductive Isolation
Can be caused by:
The evolution of different mating location, mating time, or mating rituals:
                                                                  
   
Different species of bowerbird construct elaborate bowers and decorate them with different colors in order to woo females. The Satin bowerbird (left) builds a channel between upright sticks, and decorates with bright blue objects, while the MacGregor’s Bowerbird (right) builds a tall tower of sticks and decorates with bits of charcoal. Evolutionary changes in mating rituals, such as bower construction, can contribute to speciation.

12. Sympatric Speciation Occurs because of reproductive isolation
Two subgroups of the same population
Competing individuals of a population adapt to different food sources to ensure survival
They may no longer interbreed
                                                                                                                                  

13. Rates of Speciation
Gradualism – speciation occurs at a gradual stable rate
Punctuated equilibrium – speciation occurs in bursts – sudden changes