2 Biology 2016-4-20 cannus stannous full lab report (NO Cover PAGE) PDF

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Dr. Kepner's class, Cannus stannous full lab report...

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Sarah Long Spring 2016 General Biology II Lab 20 April 2016 Dr. Costello “Survival of the Fittest: Cannus Stannous Edition” RESULTS Data collected regarding the small population is displayed in Table 1 below. Table 1 includes (for the small population) the average temperature change and the frequency of each allele for size, skin, and water for each generation. Of the 4 individuals in each generation, the two that experienced the lowest temperature change, meaning the least loss of heat, were those that survived onto the next generation. The two that experienced the greatest loss of heat were eliminated. The two surviving individuals were used in the dice roll to determine traits for the 4 individuals in the next generation. Table 1 Table 1. Regarding small population: average temperature change (in oF) for each generation, frequency of each size can for each generation, frequency of each skin type for each generation, and frequency of each water amount for each generation.

Generation

0 1 2 3 4 5 6 7 8

Avg. temp. change 16.6 14.7 16.3 11.95 12.5 10.8 10.6 12.8 12.5

SIZE (frequency)

SKIN (frequency)

16 oz

12 oz

6 oz

Insulation

Bare metal

0.25 0.50 0.50 1.00 1.00 1.00 1.00 1.00 1.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.75 0.50 0.50 0.00 0.00 0.00 0.00 0.00 0.00

0.50 0.50 0.75 0.25 0.50 0.50 0.50 0.25 0.50

0.50 0.50 0.25 0.75 0.50 0.50 0.50 0.75 0.50

Wet cloth

WATER (frequency) 3/4 1/2 full full

1/4 full

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.25 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.50 0.50 0.50 0.25 0.00 0.00 0.00 0.00 0.00

0.25 0.50 0.50 0.75 1.00 1.00 1.00 1.00 1.00

2 Data regarding frequency of alleles for size, skin type, and water volume is also displayed in Figures 1 through 3 below. Figure 1 Figure 1. Regarding small population: size frequency of Cannus stannous across generations 0-8. Generation on x-axis, frequency of 16 oz. size, 12 oz. size, and 6 oz. size on y-axis.

Size frequency of Cannus stannous (small population) 1.2

Frequency

1 0.8

16 oz 12 oz 6 oz

0.6 0.4 0.2 0 0

1

2

3

4

5

6

7

8

Generation

Figure 2 Figure 2. Regarding small population: skin type frequency of Cannus stannous across generations 08. Generation on x-axis, frequency of insulation, bare metal, and wet cloth on y-axis.

Frequency

Skin type frequency of Cannus stannous (small population) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

Insulation Bare metal Wet cloth

0

1

2

3

4

Generation

5

6

7

8

3 Figure 3 Figure 3. Regarding small population: water volume frequency of Cannus stannous across generations 0-8. Generation on x-axis, frequency of ¾ full, ½ full, and ¼ full on y-axis.

Water volume frequency of Cannus stannous (small population) 1.2 1 Frequency

0.8

3/4 full 1/2 full 1/4 full

0.6 0.4 0.2 0 0

1

2

3

4

5

6

7

8

Generation

For the small population, generation 0 began with three 6 oz. cans and one 16 oz. can, with no 12 oz. cans, as shown in Table 1 and Figure 1 above. The 12 oz. allele was never present in these trials. Over time, the allele for 6 oz. was eliminated and beginning with generation 3, 100% of the Cannus stannous were 16 oz. in size. Skin type began with two insulated cans and two with just bare metal, and none covered with wet cloth, as shown in Table 1 and Figure 2 above. The wet cloth allele was never present in these trials. Over time, neither the insulation allele nor the bare metal allele were eliminated; by generation 8, there were two individuals with insulation and two with just bare metal. Water volume began with one individual ¾ full, one individual ½ full, and two individuals ¼ full, as shown in Table 1 and Figure 3 above. The allele for being ¾ full was eliminated after generation 0; generation 1 began with 2 individuals ½ full and 2 individuals ¼ full. Over time the allele for being ¼ full was eliminated and beginning with generation 4, all individuals were ½ full.

4 Data collected regarding the large population is displayed in Table 2 below. Table 2 includes (for the large population) the average temperature change and the frequency of each allele for size, skin, and water for each generation. Of the 4 individuals in each generation, the two that experienced the lowest temperature change, meaning the least loss of heat, were those that survived onto the next generation. The two that experienced the greatest loss of heat were eliminated. The two surviving individuals were used in the dice roll to determine traits for the 4 individuals in the next generation. Table 2 Table 2. Regarding large population: average temperature change (in oF) for each generation, frequency of each size can for each generation, frequency of each skin type for each generation, and frequency of each water amount for each generation.

Generation 0 1 2 3 4 5 6 7 8

Avg. temp. change 17.65 15.23 14.11 12.18 12.05 9.99 10.24 10.97 10.52

SIZE (frequency) 16 oz 12 oz 6 oz

SKIN (frequency) Insu- Bare Wet lation metal cloth

WATER (frequency) 3/4 full 1/2 full 1/4 full

0.290 0.375 0.542 0.750 0.708 0.833 0.791 0.667 0.709

0.291 0.417 0.458 0.291 0.333 0.416 0.500 0.542 0.584

0.250 0.292 0.333 0.375 0.375 0.375 0.333 0.584 0.625

0.210 0.250 0.167 0.125 0.125 0.125 0.167 0.208 0.208

0.500 0.375 0.291 0.125 0.167 0.042 0.042 0.125 0.083

0.542 0.458 0.542 0.667 0.625 0.542 0.458 0.333 0.333

0.167 0.125 0.000 0.042 0.042 0.042 0.042 0.125 0.083

0.333 0.292 0.458 0.500 0.500 0.542 0.667 0.333 0.250

0.417 0.416 0.209 0.125 0.125 0.083 0.000 0.083 0.125

Data regarding frequency of alleles for size, skin type, and water volume is also displayed in Figures 4 through 6 below.

5 Figure 4 Figure 4. Regarding large population: size frequency of Cannus stannous across generations 0-8. Generation on x-axis, frequency of 16 oz. size, 12 oz. size, and 6 oz. size on y-axis.

Frequency

Size frequency of Cannus stannous (large population) 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

16 oz 12 oz 6 oz

0

1

2

3

4

5

6

7

8

Generation

Figure 5 Figure 5. Regarding large population: skin type frequency of Cannus stannous across generations 08. Generation on x-axis, frequency of insulation, bare metal, and wet cloth on y-axis.

Skin type frequency of Cannus stannous (large population) 0.8

Frequency

0.7 0.6 0.5

Insulation Bare metal Wet cloth

0.4 0.3 0.2 0.1 0 0

1

2

3

4

Generation

5

6

7

8

6 Figure 6 Figure 6. Regarding large population: water volume frequency of Cannus stannous across generations 0-8. Generation on x-axis, frequency of ¾ full, ½ full, and ¼ full on y-axis.

Frequency

Water volume frequency of Cannus stannous (large population) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

3/4 full 1/2 full 1/4 full

0

1

2

3

4

5

6

7

8

Generation

The average temperature change across all generations for the small population, based on the data shown in Table 1 above, is 13.19oF. The average temperature change across all generations for the large population, based on the data shown in Table 2 above, is 12.55 oF. The comparison between these two sets of data is shown in Figure 7 below. Figure 7 Figure 7. Small and large populations: average temperature change plotted against generations 0-8.

Avg. temp. change (degrees F)

Avg. temp. change (small vs. large population) 20 18 16 14 12 10 8 6 4 2 0

Large population Small population

0

1

2

3

4

Generation

5

6

7

8

7 For the large population, generation 0 began with twelve 6 oz. cans, seven 16 oz. cans, and five 12 oz. cans, as shown in Table 2 and Figure 4 above. All three alleles for size remained present throughout these trials. Over time, the allele frequencies shifted – by generation 8, there were seventeen 16 oz. individuals, five 12 oz. individuals, and only two 6 oz. individuals. Skin type began with 7 insulated cans, 13 with just bare metal, and 4 covered with wet cloth, as shown in Table 2 and Figure 5 above. All three alleles for skin type remained present throughout these trials. Allele frequencies shifted throughout these trials slightly in favor of insulation – by generation 8, there were 14 individuals with insulation, and 8 with just bare metal, and only 2 with wet cloth. Water volume began with 6 individuals ¾ full, 8 individuals ½ full, and 10 individuals ¼ full, as shown in Table 2 and Figure 6 above. All three alleles for water volume remained present throughout these trials. Allele frequencies shifted throughout these trials in favor of being ¾ full – by generation 8, there were 15 individuals ¾ full, 6 individuals ½ full, and 3 individuals ¼ full. Table 3 below presents the expected ranking of all phenotypes from best (1) to worst (27). These expected rankings were calculated by adding up the frequency in generation 8 of each of the three alleles that make up phenotype, because generation 8 representative of is those individuals that survived the process of natural selection.

8

Table 3 Table 3. Regarding large population: average expected ranking of phenotypes shown from best (1) to worst (27). Calculated by adding frequencies shown in Table 2 for each allele in generation 8 – highest value is ranked highest, lowest value is ranked lowest. Phenotype rankings best to worst 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Size

Skin type

Water volume

16 oz 16 oz 16 oz 16 oz 12 oz 16 oz 6 oz 16 oz 16 oz 12 oz 12 oz 16 oz 6 oz 6 oz 12 oz 16 oz 12 oz 6 oz 6 oz 12 oz 6 oz 12 oz 6 oz 12 oz 6 oz 12 oz 6 oz

Insulation Bare metal Insulation Insulation Insulation Wet cloth Insulation Bare metal Bare metal Bare metal Insulation Wet cloth Bare metal Insulation Insulation Wet cloth Wet cloth Insulation Wet cloth Bare metal Bare metal Bare metal Bare metal Wet cloth Wet cloth Wet cloth Wet cloth

3/4 full 3/4 full 1/2 full 1/4 full 3/4 full 3/4 full 3/4 full 1/2 full 1/4 full 3/4 full 1/2 full 1/2 full 3/4 full 1/2 full 1/4 full 1/4 full 3/4 full 1/4 full 3/4 full 1/2 full 1/2 full 1/4 full 1/4 full 1/2 full 1/2 full 1/4 full 1/4 full

Based on the rankings shown in Table 3 above, the average rankings of the phenotypes in each of the 9 generations of the large population are shown in Figure 8 below.

9

Figure 8 Figure 8. Average rankings of phenotypes in the large population. Phenotypes of individuals are ranked in each individual generation according to the rankings in Table 3. +/- SEM bars of +/- 1 displayed on each individual generation’s bar (assuming equal variance).

Average phenotype rankings in large population

Error ranking

8 7 6 Mean value (highest ranked phenotype) Mean value (lowest ranked phenotype)

5 4 3 2 1 0 0

1

2

3

4

5

6

7

8

Generation

DISCUSSION Based on the data shown in the figures and tables above, the alleles with the most success in the large population were the alleles for 16 oz. size, insulated skin, and ¾ full. The alleles with the least success were the alleles for 6 oz. size, wet cloth skin, and ¼ full. Since success across generations was based on temperature change for this experiment with the individuals experiencing the least temperature change surviving into the next generation and those with the greatest heat loss dying off, it can be assumed that larger size and larger water volume is the most effective in retaining heat. Insulated skin also helps retain heat, based on these data. Individuals with a smaller size and less water volume were those that experienced the greatest temperature loss, thus dying off. Differences were shown in the large population versus the small population. In the small population, with 4 individuals per generation, alleles were completely eliminated throughout the

10 course of the trials. For example, the alleles for 12 oz. size, 6 oz. size, wet cloth skin, ¾ full water volume, and ¼ full water volume were not present in the later generations; all individuals were 16 oz. in size, ½ full, and had either bare metal skin or insulation (Table 1). In the large population, however, all alleles remained present throughout the course of the trials – some diminished, but none were completely eliminated (Table 2). This demonstrates the way that larger populations allow for the continuity of more alleles than do smaller populations. Considering the data collected in this experiment, natural selection certainly plays a large role in evolution. The individuals with the more desirable traits that are better suited to their environments survive, while the weaker ones die off. Evolution serves to adapt species to their environment as best as possible. The Cannus stannous, in this instance, needed the ability to retain heat to succeed and survive in their environment – those who were able to retain the most heat survived while the others died off. As the surviving individuals reproduced desirable traits were passed on from generation to generation. In this case the most desirable traits were 16 oz. size, insulation, and ¾ water volume (Table 3, Figure 8). These traits had the highest frequency in the later generations as the population evolved to meet the needs of the environment, which was storing heat. In addition to evolution, genetic drift played a large role in this experiment, in the small population particularly. As generations reproduced undesirable traits were eliminated and successful ones continued and were passed on. In the small population, the alleles for 12 oz. size, 6 oz. size, wet cloth skin, ¼ full water volume, and ¾ water volume were eliminated entirely by generation 8 (Table 1, Figure 1, Figure 2, Figure 3). The genotypes became more uniform as time went on as individuals died off instead of reproducing. Because of this the small population evolved greatly over the 8 generations. Generation 0 had significant amount of genetic variety, while Generation 8 had only one size, one skin type, and two water volumes (Table 1).

11 Mutation played a small role in this experiment because rolling a 1 or 12 on the die resulted in a genetic mutation altering the phenotype of that particular individual in the generation. In the small population specifically only one or two mutations were seen but they did change the phenotypes of the individuals. This can account for the survival of the less desirable genes, 6 oz. size and wet cloth skin in the large population (Table 2). Mutation affects natural selection because mutations help drive evolution in some cases – some are favorable and thus help a population survive and thrive over time. Mutations have a more profound effect at the end of the experiment because it alters the phenotypes being expressed more drastically than in the beginning – in the beginning, all alleles are expressed in relatively equal quantities and so a single mutation does not change that dramatically. When most of the undesirable traits have been eliminated by natural selection around Generations 7 and 8, however, and a mutation occurs, it alters the entire genetic makeup of the population and gives that allele another chance at succeeding in the population. Gene flow also played a small role in this experiment in the way that the large population was composed of 6 small populations combined. The genes of these 6 populations combined to make the gene pool of the large population, allowing for the introduction of new genes into the population and more genetic variety. In the large population, no alleles were entirely eliminated due to the gene flow between the small populations (Table 2, Figure 4, Figure 5, Figure 6). Because of this the large population did evolve, but not extensively. Since no genes were entirely eliminated the genotypes of generation 0 were similar to the genotypes of generation 8. Because of these different elements the small population is not as variable than the large population is. There is more genetic variety in the large population, and every allele is still present in Generation 8. 5 of the 9 alleles were eliminated completely by Generation 8 in the small population. However, the large population is more variable in Generation 0 than in Generation 8 – while no alleles were completely eliminated, the population did evolve in favor of being 16 oz. in size, having

12 insulation for skin, and having a ¾ full water volume. The slow speed of evolution as opposed to the quicker speed seen in the small population can be attributed to the larger population size. Though the large population did not evolve as quickly or drastically as the small population, natural selection still did drive the process of evolution in favor of the few desirable traits. The optimal phenotype in this experiment is 16 oz. size, insulated skin, and ¾ full because these three traits were the best at retaining heat. The small population evolved to an optimal phenotype in every category except water volume, which was ½ full instead of ¾. Of all of the small populations, only one evolved to the optimal phenotype at the end of the experiment – the rest came close but didn’t have all three desirable traits. Had the experiment continued through more generations it is likely that more populations would have evolved to the optimal phenotype because the larger population size causes a slower rate of evolution. It is likely that all of the small populations did not evolve to the optimal phenotype due to experimental error of some sort, whether it be the thermometers giving improper readings or some outside source. Outside sources could include heat from experimenters’ hands warming the cans, or temperatures being different throughout the room due to things such as lights, et cetera. Aside from experimenter’s error, it is possible that the beginning phenotypes of the different small populations were such that did not allow for them to evolve to 16 oz., insulated, and ¾ full. For example, one population started with three 6 oz. individuals and one 12 oz. individual, and three individuals that were only ¼ full – it would take several generations to evolve to 16 oz. size and ¾ full, and the experiment only carried through 8 generations. REFERENCES Phifer Rixey, Megan, Francois Bonhomme, Pierre Boursot, Gary A. Churchill, Jaroslav Plaek, Priscilla K. Tucker, and Michael W. Nachman. “Adaptive Evolution and Effective Population Size in Wild House Mice.” Molecular Biology and Evolution 29. 10 (2012): 2949-2955. Web. 10 April 2016....