The rarefaction technique was developed by Howard Sanders in the biodiversity analysis of Marine benthic ecosystems in 1968. The rarefaction curve is to randomly select a certain number of individuals from the sample, and count the number of species represented by these individuals. The curve is composed of the number of individuals and species. It can be used to compare the abundance of species in samples with different sequencing data volumes, and explain whether the amount of sequencing data of a sample is reasonable. Rarefaction Curve https://www.microbialtec.com/rarefaction-curve.html