  One of the most vital observational clues for unraveling the origin of
Brightest Cluster Galaxies (BCG) is the observed alignment of the BCGs with
their host cluster and its surroundings. We have examined the BCG-cluster
alignment effect, using clusters of galaxies detected from the Sloan Digital
Sky Survey (SDSS). We find that the BCGs are preferentially aligned with the
principal axis of their hosts, to a much higher redshift (z >~ 0.3) than probed
by previous studies (z <~ 0.1). The alignment effect strongly depends on the
magnitude difference of the BCG and the second and third brightest cluster
members: we find a strong alignment effect for the dominant BCGs, while less
dominant BCGs do not show any departure from random alignment with respect to
the cluster. We therefore claim that the alignment process originates from the
same process that makes the BCG grow dominant, be it direct mergers in the
early stage of cluster formation, or a later process that resembles the
galactic cannibalism scenario. We do not find strong evidence for (or against)
redshift evolution between 0<z<0.45, largely due to the insufficient sample
size (< 200 clusters). However, we have developed a framework by which we can
examine many more clusters in an automated fashion for the upcoming SDSS
cluster catalogs, which will provide us with better statistics for systematic
investigations of the alignment with redshift, richness and morphology of both
the cluster and the BCG.
