• Reproductive behaviors of various species oftentimes determines which genes evolve.bugs reproductions image by Marek Kosmal from Fotolia.com
  
  At the roots of reproduction lays one of the general principles of evolution--passing on genetic material. Every living creature's body has become a tool that is utilized by the genes as a method to propagate into future generations. Different species show a variety of variable behaviors, many of which can ultimately be led back to reproductive-success.
  
  

Displays

• Displays in behavior encompass a variety of actions, many of which can be difficult to explain without understanding their connection with reproduction. Males within many species often perform these displays in an attempt to impress or entice female counterparts. It is most commonly thought that displays are performed as an effort to signal health and vitality to the members of the opposite sex in an attempt to interest them. Displays can include activities, such as fighting between males--which commonly occurs in species of deer and moose--to musical actions, such as singing songs, which can be found in some species of birds and crickets.
  
  

Dimorphisms

• A sexual dimorphism is considered to be a difference in the looks between two sexes within an individual species. This sexual difference results from females within a species showing interest within one physical characteristic that males display, resulting in males with this characteristic--as well as females interested in this characteristic--being propagated into future generations, also known as "runaway selection."
  
  During times of female fertility, these sexual dimorphisms are displayed to females, usually by a typical showmanship behavior. Examples include a peacock with its large colorful feathers, which are spread in front of females. Many species of fish also have bright and colorful sexual dimorphisms, which they also display in various movements to females.
  
  

Building Behaviors and Gifts

• Many other animals will attempt to perform reproductive behaviors that have a basis upon the materialism of the female animals. Within sexual selection, one of the key characteristics that females search for is the ability to find males that have the means and materials by which they will be able to take care of them and their offspring. One example is the bower bird, which creates very intricate nests with special designs, which compete with other males in an attempt to lure in females.
  
  Some other species will even bring gifts--such as food--to interest the female into allowing them to reproduce. Even humans show examples of gift-giving, which can be commonly seen during the process of dating.