Mathematical Biology Seminar Alan R. Rogers, Stephen P. Wooding, Anthropology, University of Utah Wednesday, Sept. 22, 2021 3:05pm on Zoom Expectation of the Site Frequency Spectrum Abstract: The site frequency spectrum describes variation among a set of n DNA sequences. Its i'th entry (i=1,2,...,n-1) is the number of nucleotide sites at which the mutant allele is present in i copies. Under selective neutrality, random mating, and constant population size, the expected value of the spectrum is well known but somewhat puzzling. Each additional sequence added to a sample adds an entry to the end of the expected spectrum but does not affect existing entries. This talk will introduce the underlying ideas from population genetics to help us understand this behavior.