LOL! As if it's likely that, after something like 30 thousand years of interbreeding before emigration to, engineering for and adaptation to one planet after another, anything like the old human races of today would survive! Here and there you might see an odd group of isolated eccentrics maintain an ethnic identity from our own time (in one story, the characters encounter Jews on Trantor!), but this would very much be the exception to a repeatedly-blended and then re-separated rule.