I've been a long time Wiki lurker, looking at articles and reading discussion pages. I've been around for a number of years in some form or another making a minor edits here and there mostly in global warming or botanically related articles. Generally I think I understand things far better than my level of direct involvement (edit count) would suggest. I figure I am not the only one like this and do find folks dismissing people with low edit counts as being unaware of history, discussions, or rules to be quite discouraging.
My education includes, a BSc. in Ecology and a MSc. in Botany at the University of Manitoba in Canada. I've held a number of interesting jobs since finishing my education, working as a technician at Fisheries and Oceans (Arctic Stock Assessment Unit) and as a Sessional Instructor (Ecology) and Lab Coordinator at the University of Manitoba. Currently I am a Senior Technician in Biological Sciences.
I generally consider my lack of expertise to be the major reason I have not edited more. I do realize subject mastery in the form of a PhD is not required I generally figure one should have some level of formal training to properly evaluate sources and weight things correctly.