Port dependencies

[Andrey Shuvikov]

Hello,

I'm trying to figure out port dependencies on my (freshly installed)
FreeBSD 7.0. For example, I have two automake ports:

$ pkg_info | grep automake-1
automake-1.5_4,1    GNU Standards-compliant Makefile generator (1.5)
automake-1.6.3      GNU Standards-compliant Makefile generator (1.6)

I didn't install them myself, so I tried to figure out how they were
installed. But when I run

$ pkg_info -R 'automake-1*'

It doesn't show any dependencies (and I didn't delete any packages
yet). Is there a way to figure out who (which port) installed them and
do I need them both now?

Thanks,
Andrey