Succession and Natural selection Sheri Sexton
Primary succession is defined as “the change in species composition over time in an environment that was not previously inhabited by organisms” (Wileys Plus 2006, Chapter 6.4). You would find Primary succession in volcanic areas and glacier areas. Secondary succession is defined as “the change in species composition that takes place after some disturbance destroys the existing vegetation; soil is already present” (Wileys Plus 2006, Chapter 6.4). The secondary succession areas would be located around farms that were hit by tornadoes and were abandoned. After viewing the ecosystem succession of the animation, I believe that it is a secondary succession caused by a disturbance, which in this scenario is flooding. The flooding was cause by the beavers trying to build a pond so they could build a home. Primary succession could not be the cause because; the beaver’s home caused damage to the already exciting vegetation.
Chapter 6 critical and creative thinking question nine. The salamander’s evolution would be considered as a natural selection. Natural selection is traits that have good qualities and are passed down from generation to generation and the bad traits are left behind. The salamanders evolved slowly in order to enhance adaptation to their environment and surroundings. However, if the salamanders’ population found an aquatic environment, their limbs would provide an advantage. The salamanders born with the smaller limbs would be able to swim faster and escape from predators easier. They would be able to gather food sufficiently in order to survive.