I have taken something simple like masking tape, put it on each students wrist or around a shoe with sticky side up. Students and teachers go for a walk outdoors ( when not muddy or icy) return to the room and using magnifying lense, toothpick or tweezers have students generate a sorting or classifying activtiy that leads to classifying what they collected. I have also used petroluem jelly in petri dishes and had the students place in areas around the school to collect particles found in the air.
I have heard students come up with accurate and inaccurate comments. Since most don't recognize insect parts and seeds, they are most surprized when given a field guide to compare. You might try that. They are also, depending on the age ( 5,6 or 7th grade) not keenly aware of what makes up soil. You could do a sorting activity then classify living from non living.
As far as evolution is concerned I really never thougth of that as truly scientific becasue in the south where I am from if I allowed students to risk sharing thier concepts vs misconceptions we got into too much religion. I would not want that on video. You may see it differently.