It seems live ages ago that of troy said, "a bust? is that the wrong part of the anatomy? isn't this thread about an out house?"

Helen, there's a phylogenic connection between bust and butt. Note that the human species is unique in these two respects:
1) walks in an upright position (even for the other species of apes, this is not their primary posture), and
2) has, between the male and female of the species, significant differencein the appearance of the (ahem) mammalia.

Those two uniquenesses are not unrelated, in evolutionary (phylogenic) terms.

Aside to tsuwm: am I correct in assuming that the linguistic similarity of the terms "bust" and "butt" is merely coincidental?