Natural Selection in Pill Bugs

1. A bar graph comparing the means and standard deviations (as error bars) of the widths for the pill bugs in 8 colourations.

Graph 1: S.D represents the standard deviations.

According to the graph, there is a significant difference in the graph comparisons thus indicating the sampling from the population was not selected. However, there are more ‘less overlaps’ in the data as shown by the error bars thus confirming that although sampling errors exist, it is minimal. Therefore the standard deviation has no significant contribution to the statistical measurements.

2.

Graph 2: A scatter (x-y graph) for length and width of the pill bugs.

The graph aims to show the correlation between the measurements of the length and width of the pill bugs. The correlation between length and width for all the data collected length is approximately double the width with a variance in the standard error of +/- 0.25.

3. The measured traits of the pill bugs have no significant variation with the average of all the measurements on the bench. Therefore, in case of a colonization event, the remaining population will show the same behaviours as the original population of the pill bugs.

4. Natural selection entails the description of unique characteristics possessed by individual species to enable it to survive or reproduce thus continues to exist in a population at the expense of disadvantaged ones. The coloration trait helped to test the natural selection condition of the variation in the individual characteristics of the pill bugs population. The pill bugs are grouped in overlapping niches in the same field hence the genetic distance is small which keeps them in a higher competition (Dekker, 1997). Only a few with specific differentiation features thrives in the population. Further experiments include the genetic combination testing to determine if it is under natural selection.

Work cited

Dekker, J. “Variation in Individual Characters Among Members of the Population”, 1997.   Available at http://agron- www.agron.iastate.edu/~weeds/AG517/Content/WeedEvol/NaturalSelection/variation.ht            ml