since people like to claim that all humans were first black, does that mean white people are more evolved since they came later. ?

Being a single species - ALL human populations are equally evolved...

Whites moved north to the land of less sun strength. The body needs Vitamin D which comes from sunlight.  Having dark skin protects you from the sun so absorbs less sunlight for the needed Vitamin D.  The longer they lived up in the northern regions the less sun they received so the skin got lighter...to allow more of the weaker sun in.  Many many many generations led to a difference in the skin color because of where they lived.

.  Do note that the crackers are trying to get back to brown because they go out to deliberately tan their bodies brown.  Later...you mean like a millennium or 3?  It was a slow process.  Grass grows faster and paint dries faster...and the Giant Redwoods would still be seeds.

.   It is not so much evolution as it is ADAPTATION to their environment.  Crackers would burn to a crisp at the equator...& dark skin is not adapted to the colder reaches so they would develop weak bones and teeth.

Dark skin offers protection from burns and skin cancer in sunny climates, and pale skin offers protection from vitamin D deficiency in less-sunny climates.  Both are advantageous for their particular niche, and neither one is "more" evolved. 

Whether the first humans were black or not, the way you think of evolution isn't correct. While white people evolved later, them being more 'evolved' in the sense that they are more advanced is incorrect thinking. The lighter skin and different features they evolved simply means that it helped them survive and reproduce. These traits evolved because humans migrated away from the equator, thus the different environment (necessary for evolution) caused White people to have the traits they have. 

The claim isn't entirely correct.  The first members of our species had various skin tones and albinos were probably quite common among them.  However, no it doesn't mean that because evolution is not progress and has no direction.  Also, if you do believe in a ladder of evolution, wouldn't that mean Black people are more evolved because they've been round longer?

The first humans were not black. Most mammals have light skin that is covered by fur, and biologists believe that early human ancestors started out this way also.

"More evolved" is not an accepted concept in evolutionary biology because it is so ambiguous.

"since people like to claim..."  What people?  WHO?  The ones whose voices you hear in your head?

"...more evolved..."   ALL extant organisms--including all humans--are as evolved as they need to be.  The notion of one or another being "more evolved" is nonsensical.

No.  You would need a common ancestor against which to compare differences, and we don't have good DNA samples from people who were living 70,000+ years ago.

"More evolved" isn't a useful thing to say anyway.  Your toy dog breed may be more evolved than a wild gray wolf, but in the wild, the toy dog breed is going to be a snack for some larger carnivore where your wild gray wolf is going to be better adapted to survival in the wild.

Yep, it means white people are mutants.

After that split, the non-black branch of humanity and the four black branches each continued to evolve.