  We explore a sample of 148 solar-like stars to search for a possible
correlation between the slopes of the abundance trends versus condensation
temperature (known as the Tc slope) with stellar parameters and Galactic
orbital parameters in order to understand the nature of the peculiar chemical
signatures of these stars and the possible connection with planet formation. We
find that the Tc slope significantly correlates (at more than 4sigma) with the
stellar age and the stellar surface gravity. We also find tentative evidence
that the Tc slope correlates with the mean galactocentric distance of the stars
(Rmean), suggesting that those stars that originated in the inner Galaxy have
fewer refractory elements relative to the volatiles. While the average Tc slope
for planet-hosting solar analogs is steeper than that of their counterparts
without planets, this difference probably reflects the difference in their age
and Rmean. We conclude that the age and probably the Galactic birth place are
determinant to establish the star's chemical properties. Old stars (and stars
with inner disk origin) have a lower refractory-to-volatile ratio.
