So, why do I get so excited about non-invasive methods of collecting genetic samples? Because they can tell you a ton.
You’re probably used to thinking about genetics in terms of an individual–perhaps genetic tests for susceptibility to certain diseases, the potential for gene therapy, or of course as a convenient scapegoat for one’s height (or lack thereof).
But genetics also happen at the level of a population, of course. If you’ve ever taken a biology class, “population genetics” may give you hazy flashbacks to some guys named Hardy and Weinberg and their equilibrium, which is nice and all except for the bit where you have to assume several things that don’t really happen in real life ever (large populations with only two “flavors” of a gene that has no effect on reproductive success and can’t mutate). Where’s the fun in that?
But there are real reasons to care about a population’s genetics, and if you can get enough data from, say, a scat survey, you can look at some interesting questions, particularly if you’re thinking with species conservation in mind.