Question

Name_________________________________________Date____________________Per______

Using Fruit Loops to Model Types of Natural Selection

In this investigation you will use pieces of Fruit Loops cereal to model a population of organisms. Like all populations, these "organisms" exhibit natural variation. The main variation you will be studying is color. The color trait in Fruit Loops is polygenic, and is controlled by three genes (red, yellow, and blue). After establishing your initial population, you will be presented with a series of different environmental scenarios that will cause your population to change as a result of natural selection.




You will be given a population of organisms (a bag of cereal). DO NOT EAT THE SAMPLES. Observe the organisms and answer the pre-lab questions.

Pre-lab Questions
What is the most obvious variation that is visible in your Fruit Loop population? _________________________

Look at the Fruit Loops. Do you think this variation is caused by a polygenic or single gene trait? Explain.

Three color variations (red, yellow, and blue) exist on their own. Green, orange, and purple, however, are made when two different color Fruit loops mate! Fill in the blanks on the mating combinations that make the following colors. (You will need this information!!)
_________________ + _________________ = Green
_________________ + _________________ = Orange
_________________ + _________________ = Purple

For each type of natural selection we have learned, write what happens to the population. (Take a look back at your notes if you don’t remember!)
Type of Natural Selection
How it changes a population/which trait is favored
Stabilizing


Directional


Disruptive

Answer 1

Hope this helps :)

Step-by-step explanation:

What is the most obvious variation that is visible in your Fruit Loop population? ____Different colored Froot Loops

___Blue___ + _Yellow = Green

___Yellow__ + __Red_ = Orange

____Red_ _ + __Blue_ = Purple

How it changes a population/which trait is favored

STABILIZING

Instead of favoring individuals with extreme phenotypes, it favors the intermediate variants. Stabilizing selection tends to remove the more severe phenotypes. This means it would probably favor green, orange, and purple while disfavoring red, yellow, and blue.

DIRECTIONAL

Directional selection, is a mode of negative natural selection in which an extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype. Under directional selection, the advantageous allele increases as a consequence of differences in survival and reproduction among different phenotypes. The increases are independent of the dominance of the allele, and even if the allele is recessive, it will eventually become fixed. This means that whichever color is more extreme and advantageous, whether recessive or dominant, will eventually become fixed in the species.

DISRUPTIVE

This is the opposite of stabilizing selection. It favors the extreme phenotypes and tends to remove the intermediate variants. This means it would probably do the opposite of stabilizing selection and favor red, yellow, and blue while disfavoring green, orange, and purple.