Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS
  High-Bandwidth Version
Search Evolution  
 
Click to return to the Evolution Home Page
darwin change extinction survival sex humans religion
Darwin    
   
Sex and the Single Guppy

Intro | Discovery | Hypotheses | Simulation 1 | Analysis 1 | Simulation 2 | Analysis 2 | Conclusion | Gallery

Consider some possible hypotheses:

  1. Predators are causing guppy populations to become more drab by preying on the most brightly colored individuals and eliminating them from the gene pool.
  2. Guppy populations are evolving to more closely match -- or stand out from -- their environment.
  3. Female guppies are choosing to mate with the most brightly colored males, giving those males a higher probability of passing their genes on to the next generation.

Maybe you have a different hypothesis.

-> Check out a few simulations to see how scientists like John Endler test their hypotheses.

Intro | Discovery | Hypotheses | Simulation 1 | Analysis 1 | Simulation 2 | Analysis 2 | Conclusion | Gallery

  related web activities  
   
The Advantage of Sex
Why did sex evolve? The likely answers may surprise you.
 
 
The Mating Game
Help our contestants find the perfect date.
 
 
An Origin of Species
Witness for yourself how a new species can evolve.
 
   
  related topics  
   
  Evolution Since Darwin  
   
  Adaptation and Natural Selection  
   
  Evolution of Diversity  
 
 
       
         
 
Videos Web Activities Site Guide About the Project FAQ Glossary Site Map Feedback Help Shop