Popsim simulates either a single infinite population or a number of populations with chance variation. The student starts by setting the level of selection (shown here as no selection):

the population size:

and the starting gene frequency:

The program then starts simulating and printing out gene numbers (part of output shown):

The student can see what the ouput looks like when graphed:

The simulation can be repeated with one or more parameters changed.  Here the population size has been increased from 50 to 5,000:

Gene flow, as well as mutation, can also be included.

The program comes with a number of pre-set exercises:

A set of Exercises and Questions is also provided.  This is an excerpt: