Assignment Task: Your colleague is conducting a study of microbial communities in seawater in the Gulf of Mexico. They have used metagenomics to investigate cells that are collected on a 0.2µm-pore-size filter, as well as extracellular viruses that pass through the 0.2µm-pore-size filter concentrated via iron chloride flocculation. However, they are having trouble understanding the results. Use your knowledge to help your colleague understand the following information they have obtained:
They detect 4000 bacterial species in a sample near the coast, but detect only 2000 bacterial species in a sample offshore. They state that the bacterial community near the coast is twice as diverse as the sample from offshore.
Briefly describe why your colleague is wrong and how they should correctly determine species diversity.