How can I select only the genes with a certain variance threshold, I know techniques like Z statistic and T statistics and then calculation p-value and then correct for FWER or FDR? but is there some modern easy to use techniques that is also available in R with some solid references that I can deploy to my data? I have RNASeq FPKM dataset to be specific.

Regards

what's wrong with the typical Z and T statistics with FDR ???

See the great and well explained answer from the person below.