8/3/2019 SCI275 Succession and Natural Selection

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Succession and Natural Selection

Succession and Natural Selection

Environmental Science/SCI275

April 11, 2011

The succession in the animation is secondary succession. This is because the soil

and vegetation exists prior to the succession. The beaver dam was the disturbance that

started the succession in action. Since this started with a disturbance on an existing

vegetation and soil rich area it falls under secondary succession. Had this environment

 been uninhabited prior to the succession it would be considered primary succession. Of 

course understanding the two words goes a long way in understanding the two terms.

Primary succession is the change in species composition for an environment that had no

inhabitants. Secondary is the change in species composition after a disturbance changes

the existing vegetation.

The aquatic salamanders mutation resulting in the loss of the back legs and

shrinking of the forelegs stands to reason with the environment in which it lives. Since

its major habitat is water it is easier to swim as a snake than with limbs. This would

mean that the more slender aerodynamic mutations would make for the strongest

characteristics for survival. Other salamanders that are long distance cousins kept legs

 but have a different habitat that lends to these characteristics being more beneficial. This

would mean that as humans are distant cousins to apes the aquatic salamander is a distant

relative along a completely different evolutionary path to his four legged cousins.

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