We have seen evolution and have a rough understanding of how long it takes thanks to fossil records. It's extremely unlikely that all ethnicities could have just popped up. Not to mention we have the fossils of "humans" dating well past 10,000 years (4,000 more than creationists say the world is). And this all isn't even considering, human genetics are too complex for 2 original creatures to have started the chain. It's just not possible.