Species Accumulation Curve

The Accumulative Curve, also known as the Rarefaction Curve, is used in microbiome research to evaluate the saturation of sequencing depth or sample size. The rarefaction curve randomly extracts a certain number of sequences from each sample (i.e., resampling at a certain depth without exceeding the existing sample sequencing depth) and can predict the total number of species and the relative abundance of each species at a series of given sequencing depths. Therefore, by plotting the rarefaction curve, the diversity of each sample can be measured by comparing the number of species in the samples at the same sequencing depth. Metagenomics uses the number of species for rarefaction curve analysis.

FAQ

Q: What is the species accumulation curve used for?

A: In different groups, the samples within the group are randomly resampled. The X-axis represents the number of samples resampled and the Y-axis represents the number of species. As the number of samples increases, the number of species in each group gradually increases, and finally reaches a plateau, indicating that the current number of samples is sufficient to represent the community distribution characteristics of the group, and increasing the number of samples will not significantly increase the number of species in the group.

Because of this, the species accumulation curve has a certain requirement for the number of samples in the group (at least 3).