Preamble commands that extend the inbuilt authoryear style from BibLaTeX to support UCT's flavour of Harvard referencing.
Just copy the contents of the single .tex file into the preamble of your latex doc. Make sure you're not importing biblatex already. Remove any code that provides unwanted functionality. Comments should be pretty clear.
style=authoryear-comp: deals with papers written by the same author but in different years. Change to authoryear to have it repeat citations.
maxcitenames=2: for papers with more than 2 athors we cite first author and et al. (This is set to 2 here because of the Biology Faculty, but the official docs maintain it should be 3).
maxbibnames=8: similar to the above but for the bibliography.
giveninits=true: uses initials rather than the full names in the bibliography.
Find the full biblatex docs at http://ctan.math.washington.edu/tex-archive/macros/latex/contrib/biblatex/doc/biblatex.pdf. Specifically section 3.