question about the sample size - (May/07/2019 )

Dear All, 

I have a bacterial population in three different hosts (e.g. human, chicken and pigeon). in human i have 60 strain, chicken I have 20 and in pigeon i have 35. Now I would like to know if this is statistically correct to compare among these 3 hosts, for instance the diversity of the bacteria. I would expect that the size of the bacteria in each host would affect the conclusion that one population is more or less diverse. Am I right ? 

Are there any statistical test to run to tell if the difference in population size would or not affect any comparison among the hosts ? 

Thanks 

To do any sort of statistics to assess the diversity from each host, you would need to have several samples from each host species and assess the diversity from each sample. This would allow you to have a mean number of species and perform statistical tests. Generally you would need a sample size of 30 samples or more for parametric tests (e.g. student's t-test, ANOVA), though you can get away with fewer with some loss of power.