Interpreting p values of gls in nlme

Dear all

I have undertaken some phylogenetic and non-phylogenetic regressions with
gls() in nlme with single preictor variables. A p value is associated with
the intercept (upper p value) and another with the predictor variable
(lower). Which p value is important? What does it mean if the intercept p
value is insignificant but the predictor is still significant?

Thanks a lot, and sorry for my ignorance,

Roland