Biology Lab Report
Shalacia Gilmore Fall 2012
BIO 1107
Natural Selection Lab
INTRODUCTION
In the 1850s, two scientists by the name of Charles Darwin and Alfred Russell Wallace composed the theory of evolution by natural selection. (1) Darwin characterized several claims needed for natural selection to happen, including heritable variation within the population, and the presence of more individuals than the environment can support. They also discovered that certain environments favored certain traits. These circumstances resulted in the preferred traits being the most adaptable and able to reproduce, therefore passing the traits down to the next generation. To get a closer look at natural selection, we set up simulations to look at the reproductive success of an individual relatives to others, or biological fitness. The hypothesis we concluded for the simulations is that the predators on the light towel bench, which represents one of our three environments, would be more fit than the predator in the other two environments.
METHODS
To test this, we divided into three different groups to put in an environment as the population as predators. We used a fork, a spoon, chopsticks, and a forceps to as our utensils to acquire the prey. The prey population is represented with beans that differed in size, shape and color. For our experiment, we used lima beans, lentils, and black beans. We then scattered the beans, or the prey, through each environment for equal opportunity. At the start of the experiment, we counted 100 of each bean so that each trait (bean types) is included in a balanced portion of the population. For three rounds, we timed ourselves for one minute and attempted to catch as much “prey” as we could with our utensil. The number of prey we caught determined a predator’s fitness. The fitness of the first generation will then determine the makeup of the next generation. We used a table to compare the predator and prey in each environment for three generations. We
BIO 1107
Natural Selection Lab
INTRODUCTION
In the 1850s, two scientists by the name of Charles Darwin and Alfred Russell Wallace composed the theory of evolution by natural selection. (1) Darwin characterized several claims needed for natural selection to happen, including heritable variation within the population, and the presence of more individuals than the environment can support. They also discovered that certain environments favored certain traits. These circumstances resulted in the preferred traits being the most adaptable and able to reproduce, therefore passing the traits down to the next generation. To get a closer look at natural selection, we set up simulations to look at the reproductive success of an individual relatives to others, or biological fitness. The hypothesis we concluded for the simulations is that the predators on the light towel bench, which represents one of our three environments, would be more fit than the predator in the other two environments.
METHODS
To test this, we divided into three different groups to put in an environment as the population as predators. We used a fork, a spoon, chopsticks, and a forceps to as our utensils to acquire the prey. The prey population is represented with beans that differed in size, shape and color. For our experiment, we used lima beans, lentils, and black beans. We then scattered the beans, or the prey, through each environment for equal opportunity. At the start of the experiment, we counted 100 of each bean so that each trait (bean types) is included in a balanced portion of the population. For three rounds, we timed ourselves for one minute and attempted to catch as much “prey” as we could with our utensil. The number of prey we caught determined a predator’s fitness. The fitness of the first generation will then determine the makeup of the next generation. We used a table to compare the predator and prey in each environment for three generations. We
Cited: 1. Freeman, Scott. Biological Science, Fourth Edition. San Francisco; Pearson Benjamin Cummings, 2011.