1. + Peacocks have pretty fancy feathers. Why have they evolved this way? Explain in terms of mate selection. Alisa, Pratik, Yurie

2. + Sexual dimorphism Sexual dimorphism= Evolution of differences between males and females In some species, males have evolved exaggerated traits that advertise their reproductive worth. The colorful tail feathers of peacocks is a good example of this.

3. + Secondary sexual characteristic= Traits that are peculiar to one sex or the other but are not part of the actual reproductive organs.

4. + Extravagant traits provide an advantage in the competition for mates. Extravagant traits get passed down from one generation to the next, and through modification, the traits can become more elaborate and attractive over time. Why do male peacocks have colorful tails?

5. + The peacock's tail requires a great deal of energy to grow and maintain, it reduces the bird's agility, and it increases the animal’s visibility to predators. Yet it has evolved, indicating that peacocks prioritize reproduction in terms of survival Why do male peacocks have colorful tails?

6. + Other Examples Male deer fight with their antlers. Blackbird and their singing to attract female

7. + Bibliography http://www.slideshare.net/gurustip/e6-further-studies-of- behaviour-hl http://www.slideshare.net/gurustip/e6-further-studies-of- behaviour-hl http://www.stanford.edu/group/stanfordbirds/text/essays/S exual_Selection.html http://www.stanford.edu/group/stanfordbirds/text/essays/S exual_Selection.html http://www.thegreatdebate.org.uk/sexualselection.html