The following contains MAJOR SPOILERS for “Have You Seen Your Mother, Baby, Standing in the Shadows?” an episode of ABC’s “Life On Mars.” “Life On Mars” is settling into a routine. And for a show that is struggling to find viewers, that is not necessarily a good thing. Every week Sam solves a mystery, deals with the boorish sexism and corruption of his fellow officers, yet somehow ends up on top, with minimal if any progress made in trying to find out why he is stuck in 1973. Last week’s preview for this episode indicated that viewers would learn more about why Sam has been sent back to 1973. This episode did not provide any definitive answers, though. Sam met up with his mother, learned more about this family’s past, and prevented his mother from slipping into prostitution. (No, …