OLD! - For current see BIOSCIENCES COURSE SITE
 BIOL2007 - NATURAL SELECTION AND DRIFT PROGRAMS

DOS Programs (can also run in windows)

SUMMARY

From this page, you can download a "self-extracting archive" called NATPACK.EXE, which has two components:

NATSEL.EXE
DRIFT.EXE

... and a whole series of other files that you might need to run them.  The programs perform accurate simulations of natural selection at a single locus with two alleles (NATSEL.EXE), and genetic drift at a single locus with two alleles (DRIFT.EXE).

APOLOGIA

The programs were written for a course when I was in USA at a time when Microsoft Windows was just entering its clunky 3.0 stage (I refrain from mentioning how long ago, but you might notice from the dates the programs were saved).  Therefore, the programs don't have all the bells and whistles that you would expect in year 2000.  But, I have found that they work for DOS, Windows 3.1, 95, 98, 2000, NT and XP.  You could try it on a Mac DOS or Mac MS-Windows emulation, but I don't guarantee anything!

HOW TO DOWNLOAD

0) IMPORTANT!! SAVE ALL WORK before you start any of this!! (See also "How to run simulations" no. 3).

1) BEFORE YOU DO ANYTHING, it is a good idea to make a FOLDER, or DIRECTORY, which might be called C:\NATSEL.  If you don't have access to the C:\ drive, I suggest you try another drive, such as R:\; in which case you make an R:\NATSEL directory or folder.  If you already have such a folder or directory called NATSEL, try to empty it of stuff, because when you unpack the files, you don't want to lose them or what you had in there before.

2) DURING THE DOWNLOAD, when queried, send the file to your newly created NATSEL folder or directory.

3) To download, simply click on the download instruction here: SELECTION/DRIFT SIMULATIONS

HOW TO UNPACK

0!) If you didn't obey the how to download instruction 1 and 2 (naughty, naughty!), now's the chance to copy your NATPACK.EXE file to a directory on its own, and again, I suggest C:\NATSEL or similar.

1) To unpack the self extracting archive, go to the directory or folder.

2) For some curious reason, some college networked machines change NATPACK.EXE into NATPACK.HTM.  If this happens, rename NATPACK.HTM back to NATPACK.EXE

3) Click on NATPACK.EXE to unpack the relevant files into the local directory or folder.

4) You will get an incomprehensible burst of activity in a "DOS Window" (hopefully).  Get rid of any "inactive DOS windows".

5) In Windows 95 and above, you should see the new files in the Windows Explorer window for C:\NATSEL\.
 

HOW TO RUN SIMULATIONS

1) You can now run the DRIFT or NATSEL files by clicking on DRIFT or NATSEL icons or *.PIF files, or, failing that, on the DRIFT.EXE or NATSEL.EXE files themselves.  The former is preferable, so if they don't work, and you know how to edit ".PIF" files, you might like to try to edit them.

You must keep all the files in the same directory/folder for the programs to run (the *.BGI files do the DOS graphics).

2) The ".DOC", "README" etc. files are to try to help you.  README.BAT on Windows 95 and NT performs badly, use the doc files instead.

3) I don't advise trying to run DRIFT.EXE or NATSEL.EXE within a window.  This causes chaos because the programmes were written to address the Video screen directly, they are not "well-behaved" Windows programmes.  So long as you run them as full screen DOS programmes you'll be alright.  Otherwise you could crash your computer and lose work you have done in open windows.  

If you have a DOS Window, and want to go to full screen, press Alt-Enter; to go back to a DOS window, press Alt-Enter again.

COMMENTS, QUERIES

Try to sort out any problems (and then feel proud of yourself!), or ask someone who knows a little about computers to help.

Alternatively, you could try some of the more modern versions of similar programs.

Happy simulating!

Jim Mallet
Jan 28, 2000


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