Scribepost for 1.27.11

ANNOUNCEMENTS: We have a bio day tomorrow in the auditorium.:D

HOMEWORK: Finish the Natural Selection Lab (page 17 in the Unit Packet)

RECAP: For the whole class period we worked on a lab about Natural Selection

BACKGROUND INFO:

Natural Selection- The process by which organisms with variations most suited to their local environment survive and leave more offspring.
Basically, only certain individuals in a population produce new individuals, like in artifical selection. Natural selection occurs in any situation in which more individuals are born than can survive (the struggle for existence), there is a natural heritable variation (variation and adaptation), and there is a variable fitness among individuals (survival of the fittest).

LAB: First, we took one of the fabrics and laid it down on our table. Taking ten differently colored pieces of paper, we cut out ten holes from each of them (thats a hundred in total) and laid them randomly around the cloth. We chose two predators who randomly took the first paper chips that they saw until they reached forty. Taking eighty in total, there was supposed to be twenty left on the cloth. We recorded the number of chips there were by color on our data table. Then, we multiplied those numbers by five, which is supposed to represent the organisms reproducing. We then punched the holes needed to reach the number. For example, say that there were five yellow chips left on the cloth. Five times five is twenty-five, so the yellow chips have now grown to that number. But since you already have five chips you only need to punch out twenty more. After doing that for all the colors, we recorded our data, and repeated all of these steps for the second and third generation.

EXPLANATION: So, what did this lab have to do with Natural Selection? As explained before natural selection consists of four other parts, the struggle for existence, variation, adaptation, and survival of the fittest. The stuggle for existence is literally what it means: an individual stuggling to survive and obtain the necessities of life, and competing with others for it. In the lab, we were the predators and the paper chips were the ones struggling to survive. Variation and adaptation both mean what an individual has that helps him to survive, whether it be a trait or a stratedgy.
Adaptation-Any heritable characteristic that increases an organism's ability to survive and reproduce in its envoirnment
For this lab, the adaptation some chips had were camoflauge. Certain colors blended in with the cloth, so when the 'predators' were randomly picking chips, it would've been hard to notice one the same color as the background. A good adaptation means a high fitness level.
Fitness-how well an organism can survive and reproduce in its envoirnment
People with adaptation that were not well suited to their enviornment, like the chips that stood out, had a low fitness level. The difference in rates of survival and reproduction is called the survival of the fittest. The ones that survive are meant to then reproduce and pass adaptation on to the next generation.

The next scriber is.................Carly(=