Yeah I tried to do one of those once. I used Adobe Photoshop for this one. I'll be putting up era 2 later. Now for a description of the common techs in that era. There aren't as many.
2nd era:
1) Aristocracy
Small Wonders: Vacation Palace
2) Astronomy
Units: Galleys
Great Wonders: Great Lighthouse
3) Education
Improvements: University
Citizens: Scholars
4) Fired Goods
Resources: Glassware, Porcelain
5) Food Preservation
Improvements: Storehouse, Tavern Guild
Resources: Salt, Pottery
6) Herblore
Resources: Incense, Spices, Tobacco
7) Impressment
Improvements: Gaurd Tower
Other: Enables Drafting
8) Iron Working
Improvements: Blacksmith
Small WOnders: Iron Works
Resources: Iron
9) Literature
Improvements: Library
Great Wonders: Great Library
10) Map Making
Improvements: Privateer's Cove
Diplomacy: Enable Map Trading
11) Prospection
Resources: Jade, Cinnabar, Platinum
12) Siege Craft
Units: Advanced Artillery
13) Spell Casting
Improvements: Magic Guild
14) Sports
Improvements: Arena
15) Stirrup
Units: Light Cavalry
Small Wonders: Ylaruam Camels
16) Stone Construction
Improvements: Palace, Walls, Aqueduct
Great Wonders: Colossus
Worker Jobs: Fortress
I'll be posting the drawing of that tree tonight.