Evolution Lab 1: A Natural Selection Simulation With Speckled, Black, Round, and White Beans [GONE WRONG] [BEANS INVOLVED] (Beanboozled)

Evolution Lab 1: A Natural Selection Simulation With Speckled, Black, Round, and White Beans [GONE WRONG] [BEANS INVOLVED]  (Beanboozled)

By Toqa Abosabaa, Leah Koung, Kaveena Ranaweera, Jennifer Chin

In this lab, we hypothesized that in our model of beans the population would change over time due to Natural Selection because the beans had different size and shape. Our null hypothesis was that there was no change in the number of beans over time. It was predicted that if four different types of beans - speckled, round, black, and white - were placed in a cup and picked at random, then there would be a greater population of speckled beans as opposed to the other beans, due to the speckled beans being bigger in size, thus easier to grab.

Figure 1. Number of round, speckled/pinto, black, and white beans over ten generations in Population A. Chi-square value is 120.8. Speckled beans were greatest in number, while white, black, and round beans readily decreased during the experiment. At the conclusion of the experiment, speckled beans were found to be the greatest in number.

Figure 2. Number of round, speckled/pinto, black, and white beans over ten generations in Population B. Chi-square value is 19.1. White beans died off, while numbers of speckled, black, and round beans varied during the experiment. At the conclusion of the experiment, black beans were found to be the greatest in number.

The Chi-square value found in Population A was 120.8, while the Chi-square value found in population B was 19.1. According to the Chi-square value found in both populations, we can conclude that our null hypothesis was rejected from both populations because both chi values were greater than 7.82, the critical value. In this experiment, 25 beans of each type were randomly distributed into Populations A and B. The first alleles from both Population A and Population B of Generation 1 were recorded. Each "allele" was then doubled and mixed together, and then 50 beans were "randomly" selected and recorded for each type of "allele." Doubling and "random" selection procedure was repeated for 10 generations. Over the course of the generations in both populations, it was seen that natural selection influenced the types of beans being picked, as the allele frequency was altered through the passing of each generation due to the varied sizes of the beans. In Population A, the speckled "allele" became the dominant "allele," due to the fact that the that the speckled beans were larger and easier to grab. In Population B, the black "allele" became the dominant "allele," again due the larger size of the black beans. Although the black beans weren’t as big as the speckled beans, they were still larger than the white and the round beans, making them easier to grab, similar to the speckled beans in Population A.

The data collected from this experiment supported our hypothesis that natural selection has an effect on allele frequency, while only partly supporting our prediction that there would be a greater number of speckled beans as opposed to the other beans. As seen in Figure 1, speckled beans dominated Population A, while black beans dominated Population B, as seen in Figure 2. Both Population A and B supported our hypothesis that natural selection has an effect on allele frequency, seen in heightened number of speckled and black beans, respectively, due to their sizes.