We have done a robust statistical analysis of UBV color profiles of 257 Sbc
barred and unbarred galaxies. We found that there is an excess of barred
galaxies among the objects with null or positive (bluish inward) color
gradients, which seems to indicate that bars act as a mechanism of
homogenization of the stellar population along galaxies. Moreover, the
relationship found between total and bulge colors shows that, in the process of
homogenization, the stellar population of bulges are getting bluer, whereas the
total color of galaxies remains the same. These characteristics are expected in
a secular evolutionary scenario, and seem incompatible with both the monolithic
and the hierarchical scenarios for spiral galaxy formation.Comment: 2 pages, 1 table, no figures. To appear in ASP Conference Series,
"Galaxy Disks and Disk Galaxies", J. G. Funes S. J. and E. M. Corsini, ed