NS works because the environment changes over time and selects for characteristics that improve an organism's chance for survival in the changed environment.
(NS; works; because the environment changes over time and selects for characteristics) (the environment; changes; T:over time and selects for characteristics) (characteristics; improve; an organism's chance for survival in the changed environment)
NS the environment characteristics
works changes improve
because the environment changes over time and selects for characteristics
T:over time and selects for characteristics
an organism's chance for survival in the changed environment