erm... there is a distinct difference between species and ethnicity, but you have to realize that species is not necessarily the smallest division as some textbooks for lower grades might claim.
Just because certain ethnic group isn't a different species does not directly mean there's no difference.
There are enough studies about variations between each ethnic group, and actually, more would have existed if not because of political correctness.
you see non-scientists flame at whatever scientific study that doesn't sound good to them, and somehow some scientists are being prosecuted because of the flaming.
It simply gets in the way because people can't face reality.
Education should be teaching how to make different people live harmoniously together whilst acknowledging their differences.
Instead of political correctness.
When I was in the UK, students from my school were from more than 28 countries, we were encouraged to perform cultural exchange and much more.
There was a world map where we pin our names to our homeland, and we were assigned to bedrooms with people from different countries and ethnic group.
We acknowledge our differences, but we live in absolute harmony and are very friendly towards each other. We learn to tolerate and accept each other.
If someone accidentally says something offensive, people kindly remind them in a friendly manner, instead of flaming the whole "YOU ARE SO WRONG, GET IN JAIL NOW" sort of thing.
We don't call somebody wrong, we just say that we don't like hearing certain things.
But if a certain amount of people tells us that it doesn't actually sound that bad, we learn to deal with it.
We loved our mini-world inside the school, because we learn different things simply because we are different.
Diversity can be lovely.
If you look at other places, you can see, USA is probably the most strict about political correctness, but ironically, it is also the same place with the most arguments and most discrimination takes place.
The type of political correctness exhibited in USA actually stirs up more hatred!
Not to mention about the cultural pockets thing. It's severe in USA.
You don't see the same degree of flaming happen in say UK/ Canada or Australia.
People can properly merge into their neighborhood.
But you see, people like me is probably being labelled as bad people from the USA's standard.
Whilst in reality, I probably have befriended with more people from various ethnic groups than those people.
I have friends who are Caribbean, Indian, white African, black African, Mexican.... the list goes on.
For a broader view, I would like to introduce to you this video by Steve Hughes
(I know it's a comedy show, but he has very good points)