Genetic Biodiversity

Figure 4 Evidence: 

The Sweet Pepper Condition yielded a mean Shannon Diversity Index rating of 4.69 and a standard deviation value of 0.147. The Hot Pepper Condition yielded a mean Shannon Diversity Index rating of 4.56, and the data varied from the mean by an average of 0.137. Comparing the two data sets, the Sweet Condition’s mean was 0.29% larger than the Hot Condition’s. However, the performed unpaired T-test yielded a p-value of 0.147, meaning that the two conditions are not significantly different, as the p-value was greater than the alpha value of 0.05. 

The Sweet Pepper Condition yielded a mean richness rating of 165.75 and a standard deviation value of 13.32. The Hot Pepper Condition yielded a mean richness rating of 154.75, and the data varied from the mean by an average of 23.04. Comparing the two data sets, the Sweet Condition’s mean was 7.1% larger than the Hot Condition’s. However, the performed unpaired T-test yielded a p-value of 0.448, meaning that the two conditions are not significantly different, as the p-value was greater than the alpha value of 0.05.  

The Sweet Pepper Condition yielded a mean evenness rating of 0.918, and a standard deviation value of 0.003. The Hot Pepper Condition yielded a mean richness rating of 0.905, and the data varied from the mean by an average of 0.002. Comparing the two data sets, the Sweet Condition’s mean was 1.4% larger than the Hot Condition’s. Additionally, the performed unpaired T-test yielded a p-value of 0.0003, meaning that the two conditions are significantly different since the p-value was lesser than the alpha value of 0.05. 

The Taxonomic Bar Graph yielded some statistical differences between the phyla representation of Sweet Peppers and Hot Peppers. In particular, four out of the thirty-seven total phyla that were detected in the samples showed statistically different information. The phyla Proteobacteria, Actinobacteria, Chloroflexi, and Plactomycetota – all within the domain Bacteria – yielded p-values lower than 0.05 when an unpaired t-test assuming unequal variance was performed.  For all the phyla mentioned above, the Sweet Pepper condition had a greater number of species within each phylum compared to the Hot Pepper condition. The largest difference was within the phylum Proteobacteria, with the Sweet Pepper Condition having 27.8% more species within the phylum than the Hot Pepper Condition.  

 
Figure 4 Conclusion: 

Condition 1 and Condition 2 provided similar Shannon Diversity Indexes and richness ratings, of 4.56 and 154.75 (hot peppers, condition 1) and 4.69, 165.75 (sweet peppers, condition 2) respectively. When a t-test was conducted, the p-values were 0.147 and 0.448 respectively, indicating that the analyses of the two conditions are not statistically different, and any variation is due to chance. The p-value for each is greater than 0.05 providing 95% confidence that the data is not statistically different.  

Condition 1 (hot peppers) have an evenness value of 0.905 and Condition 2 (sweet peppers) have an evenness value of 0.918. As the standard deviation is low, the p-value provided by a t-test is less than 0.05 at 0.000333. This low p-value implies a statistical difference between the evenness values. Evenness values are measured from 0-1, indicating that the experimental evenness values are high. The evenness values display that the area being covered by the microbiome differs.  

49.434% of the phyla of the two conditions are statistically different. Phyla’s Proteobacteria, Actinobacteriota, Chloroflexi, Planctomycetota, NB1-j provided p-values of less than 0.05. All 5 phyla are a part of the Bacteria domain. While the phyla are only 5/36 (13.89%) of the phyla’s found, their prosperity in the microbiome is 49.434%. 50.566% of the microbiome data has no statistical difference between the two conditions, providing 95% confidence.  

 
Figure 4 Explanation: 

The two soil samples taken were from the same species (Capsicum) and from the same garden, yielding similar environments and similar soil types. Additionally, the two areas both had consistent soil textures, both very alike to sandy loam, which is the soil type ideal for pepper plants. (Brandenberger et al) Due to the related conditions of environment, a similar microbiome would be expected as shown through the results of the experiment. Additionally, the t-test executed resulted in a p-value which yielded no statistical difference between the two conditions. This provides explanation for the no statistical difference in Shannon Diversity and Richness index. Our evenness value differences can be attributed to the heterogeneity of the landscape and location from which the samples were taken. The two different locations can cause differences in light, sediment, accessibility, etc. impacting evenness (Huang et al.) For the differences in relative abundance of certain phyla, that can be explained by understanding that each phylum thrives in very specific conditions, meaning even slight differences in soil conditions can contribute to large discrepancies in phyla distributions among the samples (Zhou et al.)