  The origin of the star-to-star abundance variations found for the light
elements in Galactic globular clusters (GGCs) is not well understood, which is
a significant problem for stellar astrophysics. While the light element
abundance variations are very common in globular clusters, they are
comparatively rare in the Galactic halo field population. However, little is
known regarding the occurrence of the abundance anomalies in other environments
such as that of dwarf spheroidal (dSph) galaxies. Consequently, we have
investigated the anti-correlation and bimodality of CH and CN band strengths,
which are markers of the abundance variations in GGCs, in the spectra of red
giants in the Sculptor dwarf spheroidal galaxy. Using spectra at the Na~D
lines, informed by similar spectra for five GGCs (NGC 288, 1851, 6752, 6809 and
7099), we have also searched for any correlation between CN and Na in the
Sculptor red giant sample. Our results indicate that variations analogous to
those seen in GGCs are not present in our Sculptor sample. Instead, we find a
weak positive correlation between CH and CN, and no correlation between Na and
CN. We also reveal a deficiency in [Na/Fe] for the Sculptor stars relative to
the values in GGCs, a result which is consistent with previous work for dSph
galaxies. The outcomes reinforce the apparent need for a high stellar density
environment to produce the light element abundance variations.
