It appears to be Unix tradition that a wheel group is created automatically, but Debian (and children, naturally) doesn't do so. Is there a rationale somewhere? Where else have you seen this tradition discarded?
Why is Debian not creating the 'wheel' group by default?
debian;group
Some unix systems allow only members of the wheel group to use su. Others allow anyone to use su if they know the password of the target user. There are even systems where being in the wheel group grants passwordless root access; Ubuntu does this, except that the group is called sudo (and doesn't have id 0).I think wheel is mostly a BSD thing. Linux is a mix of BSD and System V, and the various distributions have different default policies with respect to granting root access. Debian happens not to implement a wheel group by default; if you want to enable it, uncomment the auth required pam_wheel.so line in /etc/pam.d/su.