Do you think the differences between cultures and ethnicities will change over time?

There is a big difference between ethnicities and cultures. In many ways, we are becoming more multi ethnic all the time, people have much more diverse genetic backgrounds than people one hundred years ago.

But culturally, there seem to be too many divisive factors at play, religions, language, climate, politics.

What in this world _doesn’t _ change.

As to your question:

An obliteration of ethnic differences is not required for mankind to function as a forward thinking, science, innovation and exploration based whole.

However. If your people are still strapping bombs to their chests in the name of some fictional being you’re gonna slow things up a bit.

I doubt it. Not being pessimistic. Just too many variables to have to come together at the exact same time. The conflicts you see today are part of the human dilemma.
See @SecondHandStoke
What ever you dream about a unified humanity, it certainly will never happen as long as people believe it will be accomplished by committing mass murder in the name of mysticism.

^ Huh?

I do not recall mentioning mass murder (by those on the advanced and enlightened side), and certainly not mysticism.

Do we want that? You say race, but ethnicity is much more than “race.” I’m not sure how you are defining all of the words. Will we one day just all think in terms of human race and not black, white, Asian, etc.? I think yes. Will we one day have just one ethnicity? Do we want that? I don’t see that happening. Don’t we like a lot of our ethnic differences, different traditions, different humors, different temperaments, and different foods?

I used to do so.
I no longer hold that as possible.
There are too many with the objective not to.
Nor allow others to achieve that end.
Now?
Why bother?
I know who I am.
That’s enough.
Taking care and putting others and their needs First will never, ever, create the ideal.
Some believe that they should be first, because they’re worth it all just by ‘being’.
Humans.
C’mon apocalypse!
Better luck to the next groups…
Trilobite Wars!

They have changed over time, but not in the most acceptable ways. Man will always be Man and conflict will always be a part of the equation. If change to a more acceptable level were possible, it would not happen before Man’s extinction. (Which, IMOP, will occur fairly soon. One way or another, it is inevitable.)

Ideally we would all fuck until we are brown. Or at least a light M&M brown.

But really. Until we get rid of religion we are all fucked.

Advances in transportation and communication are making the world smaller. How willing would you be to attack the home country of someone you contact regularly on the Internet? It will take a while, but I think cultural differences will diminish.

Be careful though of what you wish for. My dystopian fantasy is of a uniform worldwide network of highways, tract housing, industrial campuses and shopping areas, where one place is indistinguishable from the next and all the work is done by robots.

Of course. Nobody brings gold, frankincense and myrrh to a king any more.