Well, thats not possible in the editor. So tough luck. As for the survival of civs:
Rome: AA (destroyer: various Germanic tribes)
Egypt: AA (destroyer: Rome, though it was ruled by other civs at times)
Greece: AA (destroyer: Rome, though it was ruled by Macedon for a while)
Babylon: AA (destroyer: Hmm. I think I'll credit that to Persia, but it was ruled by many different other countries)
Germany: MA-Still Exists
Russia: MA-Still Exists
China: AA-Still Exists
America: IA-Still Exists
Japan: AA or MA (not sure which)-Still Exists
France: MA (AA if the Franks, a germanic barbarian tribe, count as France)-Still Exists
India: AA-Still Exists, though its been ruled by England in the past
Persia: AA (destroyer: Macedon, later Rome)
Aztecs: MA (though with AA tech) (destroyer: Spain)
Zululand: ???-IA (though with AA tech) (destroyer: England)
Iroquois: ???-IA (AA tech) (destroyer: America (I think))
England: MA-Still Exists
Mongolia: AA (I think)-MA (destroyer: China, though this is disputable)
Spain: MA-Still Exists
Vikings: MA (destroyer: England sort of, after the King Harold killed King Haarald Haadarae (or whatever his name is), the Viking's culture dissapeared) (I'm not editing this again)
Ottomans: MA-Still Exists, But as Turkey
Celts: AA-MA (destroyer: England)
Arabia: MA-Still Exists (sort of)
Carthage: AA (destroyer: Rome)
Korea: MA (I think)-Still Exists, though it's been ruled by Japan in the past and it's currently two seperate countries
Sumeria: AA (destroyer: Babylon)
Hittites: AA (destroyer: Persia)
Dutch: MA (I think)-still exists
Portugal: MA-Still Exists, though it's been ruled by Spain in the past
Byzantines: AA (If Eastern Roman Empire counts)-MA (destroyer: Ottomans)
Inca: AA(I think)-MA (AA tech) (destroyer: Spain)
Maya: AA-MA (AA tech) (destroyer: None, their population disappeared)
Note: These times are reflecting when their civilization occured, and what era it was in in real history at the time, not how far they advanced. If you disagree with times of their existence and who destroyed them, tell me.
Oh, and, lengths of time in real history, though extending Middle Ages to all its civ3 tech:
AA: ???-476 AD
MA (which includes more than the actual MA in civ 3): 476 AD-1700's (exact date unknown to me)
IA: 1700's-1940
Modern Times: 1940-Present