Natural Selection - Weekly Blog (10/15-10/19)

File:Lichte en zwarte versie berkenspanner crop.jpg by Chiswick Chap

Summary:

Natural selection occurs when a species with the fittest trait survive to pass on the gene to their offspring. In other words, natural selection is when a species with a specific trait survives long enough to reproduce. This means that if there are two of the same species, however, they have a different trait, the population of the species with the fittest trait will increase because that trait helps it survive.

A good example of natural selection is the peppered moth. Before the 19th century, the air was cleaner, and the bark on trees was light in color. This meant that the peppered moths could easily blend in with the trees, and avoid predators. However, during the 19th century, many industries used coal, meaning that it polluted the air and changed the trees a darker shade of brown. This meant the peppered moths were not camouflaged with the trees, exposing them to their predators. This meant that it was difficult for the lighter moths to survive. However, now that the trees were darker, it was much easier for the darker months to survive, as they easily camouflaged with the trees. This is where natural selection takes place. With darker trees, the fittest trait is a darker color. When the darker moths survived long enough to reproduce, they passed on that gene to the next generations, increasing their population. However, the lighter moths did not survive as well, meaning that not many survived long enough to reproduce. This means that there was a much higher population of the darker months, rather than the lighter moths.

SP8: Obtain, Evaluate, and Communicate Information

This week, we obtained, evaluated, and communicated information as we dug deeper into the evolution of the peppered moth. First, we obtained information about the peppered moths, and how the tree color makes a big difference in their survival. Next, we evaluated this information and connected it to evolution to determine how the color change in the trees affected the population of each species with a different trait. Finally, we communicated the information that we collected and learned new ideas from others. Obtaining, evaluating and communicating information helped me understand more about natural selection and how it causes evolution.

XCC: Cause and Effect

This week in class, I observed a cause and effect relationship between the color of the trees and the populations of the peppered moths with different color traits. The cause is the change in the tree color from light to dark. This led to the effect that the population of the darker peppered moths increased, and the population of the lighter moths decreased. This is because the lighter moths did not survive to reproduce, however, due to the change in the trees, the darker moths reproduced and passed the gene to the future generations. Based on this relationship, I can predict that there are a lot of cause and effect relationships in natural selection, and that evolution has a big effect on many species. By noticing this cause and effect relationship, I understand more about the relationship between the tree color and the peppered moths,