For anyone considering a scientific trajectory, it's hard to both find your own niche and play into grad school admissions and tenure promotions committees' decision-making process at the same time. While getting specific will probably help your career the most, says DrugMonkey, you don’t want to rule out work that truly interests you. As DrugMonkey blogs:
Some people’s interest are going to be broader than others. Some people have experimental ADD. Sometimes the most effective science follows threads that jump across techniques, models and experimental approaches over time. Unfortunately, promotions committees may not deal very well with complexity.