Mac Pro and the Amiga

Mac OS X is based on a Posix-compliant kernel named Darwin.

The issue with getting other Operating Systems to run directly is finding drivers for Mac Hardware that work in the other OS environments. Apple provides and Boot Camp installs those drivers for Windows. For Linux, one generally needs to find a pre-compiled version that includes the needed drivers, or scour the web to find and add individual drivers and partially build it yourself.

The latest Mac hardware tends to lag in its ability to run Linux and similar OS, because Drivers for proprietary Hardware are not usually provided. They are slow to become available because they have to be written by outside programmers who must sometimes reverse-engineer the Hardware and then contribute their work to the Open Source community, usually for no monetary compensation.

So has anyone delved into this OS and discovered if it is possible to create a second Start Up disc, possibly using Boot Camp or a partition on another drive, and then load up old Amiga programs?

No, no one has done that, because it's impossible. There might be such a thing as an Amiga emulator. Try a web search.

Ubuntu is possible to install on a variety of virtualization engines as if you had a Windows machine. I don't believe Boot Camp supports it, but VirtualBox, Parallels, and VMWare have a better chance of supporting it. You'll find links to those and other options on my tip.