Indie as a style is a direct descendent of punk. It was kids having seen the punk bands playing, picking up on the DIY attitude and then trying to sound like the Byrds and the Beach Boys that spawned indie. Wouldn't indie then be a descendent of surf/psychedelia-pop genre tree? [for argument's sake, assuming your statement is true]. I don't think it's all that cut and dry, there's really no direct, singular lineage within genres of music, unless we're talking revivalism.