How does the evolutionary rate of a particular gene influence its usefulness in making cladistic comparisons?

Is it because that feature of the organism is more prominant? I need some ideas on how it makes it easier for scientists to make these cladistic comparisons.

Oh yeah. Now there is a question that will get you get lots of erudite answers on Yahoo Answers.

Since this is the chemistry section, a definition may be in order.
"cladistic" – a method of classifying organisms by common ancestry, based on the branching of the evolutionary family tree. Cladistics is currently the most popular paradigm of phylogenetic classification in biological taxonomy. (http://www.palaeos.com/Systematics/Cladistics/cladistics.htm)

Perhaps you should read on here: http://www.palaeos.com/Systematics/Cladistics/molecular.html