WEG 2e R&E

So, Ewoks have three special skills... Thrown Weapons, Glider, and Primitive Construction. Ithorians have two... Agriculture and Ecology.

If I'm a human character, can I use these? If I want to do some Ecology-like investigations, would I use base Knowledge? Science? Planetary Systems? If I'm stuck on an alien planet in just my boxer shorts, what skill would I use to make a hut, or start a garden?