SUMMARY: Genes of soil bacteria sampled in the Tibetan Plateau showed that as the environment got drier, the less diverse the genes were. Researchers wanted to compare bacterial gene diversity with the already-known diversity of genes in large animals in various environments. There were less functional genes and genes responsible for stressors as the environment got drier. Genes that code for enzymes in protein synthesis and mitosis actually increased with dryness. Genes related to movement decreased with increasing dryness. Finally, researchers found that there was a higher number of different communities of bacteria as the dryness increased.
LESSON COMMENTS: This is an interesting view of genetic biodiversity on a microscopic scale. Students probably have learned about different types of ecosystems and varying biodiversity in large animals, but it is important for them to understand that biodiversity and ecosystems come in different sizes. This type of micro-ecosystem and biodiversity can be seen in pond samples with protists (though in the case of a microscopy lab, it would be the differences in phenotype and not genotype). This is a good article to refer to or read an excerpt from for lower level science classes; the discussion and conclusion sections are not difficult to understand.
Song, H. K., Shi, Y., Yang, T., Chu, H., He, J. S., Kim, H., Jablonski, P., … Adams, J. M. (2019). Environmental filtering of bacterial functional diversity along an aridity gradient. Scientific reports, 9(1), 866. doi:10.1038/s41598-018-37565-9