MacTierra

What is it?

Tierra aims to study the evolutionary process by the instantiation of evolution in another form, namely in an ecosystem of interacting and competing machine code programs living in the Tierra environment, which emulates a massively parallel computer.

MacTierra is an independent implementation of Tierra, written largely without knowledge of the original Tierra code, but following descriptions of the system given in publications. It is thus, in some sense, an attempt at verifying the results of the original Tierra. Howerver, much effort has been put into the user interface, to make it easier to use, and thus more accessible to people. In addition, it will, in time, diverge from Tierra in the details.

Objectives

MacTierra aims to present the user with a highly interactive interface, so that simulations can be studied as they are running, saved to a file and restarted later, and the activities of the creatures within them closely monitored. Full use is made of features of the Mac OS, such as Drag and Drop, to facilitate moving creatures around and examining them as they execute instructions.

This makes it very easy to devise and execute a multitude of interesting ecological experiments, and to study the evolution of the system as a whole over time. There is much potential in Tierra-like systems to learn about ecological and evolutionary processes.

Documentation

You can read the documentation for MacTierra online, which are identical to the docs you get with the distribution.

Obtaining MacTierra

The following version of MacTierra, including documentation in HTML format and the GenebankDump program, is available from the Santa Fe FTP site:

MacTierra 1.8.7 (743 k)

Version 1.8.7 makes a small change to the format of the activity data file.

Version 1.8.6 fixes an object cloning bug in 1.8.5, and improves speed through some library optimizations.

Version 1.8.5 fixed a number of bugs in 1.8.3, including the memory leak problems, it improves the genebanking code, and adds some new data collection routines.

It is compiled as a fat binary (i.e. containing both PowerPC and 680x0 code), and run on all Macs with at least a 68020, Color QuickDraw, the Thread Manager, and the Drag Manager.

Source code

The MacTierra source code is available. This is around 100 files of mixed Object Pascal/C code, written for the Metrowerks CodeWarrior Pascal compilers. A CW Pro 1 project is included.

Although I'd be happy to hear if you grab the code and use it for useful things, I'm not very willing to provide extensive tech support to help you to get the code running under other compilers or platforms. You're on your own.

The latest general release version is available on Brian Hill's most excellent Macintosh Alife Software page.