Evolution simulation software for Evolutionary Analysis.

AlleleA1 models evolution at a single locus in an ideal population of imaginary organisms. The locus of interest has two alleles: A1 and A2. The user enters values for parameters controlling selection, mutation, migration, genetic drift, and inbreeding. As the simulation runs, the software plots a graph showing the frequency of allele A1 over time.

AlleleA1 runs in your browser.

The Shiny web app version has been discontinued.

If you still want it, you can download the (very old) AlleleA1 application:

AlleleA1 for Mac OS X
  • Please note: To run AlleleA1 for the first time, you may need to hold down the control key, click on the AlleleA1 icon, and select Open from the popup menu that appears. (This is necessary because I am not a registered developer with Apple.)

  • If these instructions don’t work, open System Preferences and select Security & Privacy. On the General pane, change “Allow apps downloaded from:” to “App Store and identified developers.” Then try again.

    AlleleA1 is compiled for 64-bit processors and should run on Mac OS 10.15 Catalina.

AlleleA1 for Windows
  • Please note: Do not delete the folder called AlleleA1 Libs. AlleleA1 needs it to work properly.
  • Please note: The first time you open the AlleleA1 application on Windows you may see a dialog box titled “This application may depend on other compressed files in this folder.” Click the Extract All button (not the Run button). If you just click the Run button, you’ll get a Runtime Error message. You may also see a dialog box that says “Windows SmartScreen prevented an unrecognized app from starting.” This is because I am not a registered developer. Click on “More info,” then on “Run Anyway."

Read or download the manual:

Population genetics tutorials using the AlleleA1 application:

Fine Print:

AlleleA1 2.0 © 2003 by Jon C. Herron

AlleleA1 is free. You may give it to anyone you like, so long as you distribute it as a stand-alone application and include the manual along with it. You may not sell it. You may not include it in a collection with other software, regardless of whether you are selling the collection or giving it away.

I make no warranties or guarantees about the quality of AlleleA1, or the accuracy of the simulations it runs. Use it in good health, but at your own risk.

If you have comments or suggestions, please send them to me at herronjc at