Succession And Natural Selection – Essay Example
Primary succession is the process where all of the vegetation in an area is totally destroyed by some sort of catastrophe. This could include eventssuch as a volcanic eruption or perhaps the scraping and removal of soil by glaciers. When this happens, the plant species that come to inhabit the newly cleared area might need to be able to exist on bare rock. Plants such a lichens can do this, but other plants such as grasses and woody herbs need sand and some soil. After a long time, the decomposition of these plants will create the nutrients in the soil necessary for other species to move in and take over. That is what is happening in this problem, so this is an example of primary succession.
The mussels are an interesting study in how evolution can happen very quickly. It was interesting to note that the mussels ability to thicken its shell wasnt the real indicator of evolution. All of the mussels in the north and in the south could do this. What indicated the real evolution was the southern mussels had the ability to pick-up in the chemical signal made by the invasive crabs, but the ones in the north did not. Often, we look for an easily identifiable feature, such as a longer beak or shorter legs, as an indication of evolution and natural selection. As a result of this, I feel that we overlook many of the evolutionary changes that occur in the natural world all the time.