Origins of the pale skin color in Europeans

[Anomalocaris]

There may have been "racial distinctions" within Homo Erectus,

I'm not so sure that "we" aren't HE, though. That's where the HE dna comes in.

I think you still need to see Haldane's rule to understand why instances of cross breeding producing fertile offsprings does not prove two populations are of the same species. Speciation does not occur abruptly. There would always be some substantial stage during speciation where the ability to hybridize and produce fertile offspring is severely constrained, but not eliminated. Generally it is thought perper speciation occurs before the constrain reach a point where hybridization produces a severe imbalance of sexes amongst the fertile offsprings.