I-Evolution Series iwuchungechunge lwezitimela zikadizili ezakhiwe i-GE Transportation Systems (manje ephethwe ngabakwa-Wabtec), ekuqaleni ezakhelwe ukuhlangabezana namazinga okukhishwa kwegesi e-Tier 2 ye-U.S. EPA's Tier 2 eqale ukusebenza ngo-2005. Ulayini ulandela ngqo i-GE Dash 9. Uchungechunge. Amayunithi okuqala angaphambi kokukhiqiza akhiwa ngo-2003. Izitimela ze-Evolution Series zifakwe ama-AC noma ama-DC traction motors, kuye ngokuthandwa yikhasimende. Zonke zinikwa amandla injini ye-GE GEVO.[4]

I-Evolution Series yaqanjwa njengenye ye-"10 Locomotives That Changed Railroading" yi-Trains Magazine futhi kwaba ukuphela kochungechunge lwesitimela olwethulwa ngemva kuka-1972 ukuze lufakwe kulolo hlu.[5]

Izitimela ze-Evolution Series zingabanye bezitimela zempahla ezithengiswa kakhulu neziphumelela kakhulu emlandweni wase-United States.

Lezi zitimela zifakwe izimpondo ze-Nathan Airchime K5HL, nokuhlehliswa kwe-2, okwenza i-K5HLR2. Izimpondo zifakwe emuva izinsimbi ezi-2 zibheke phambili kuphela nezinsimbi ezi-4 zibheke emuva. Zonke izitimela zisebenzisa lezi zimpondo, ngaphandle kwe-ET23DCM kanye nezitimela zamazwe ngamazwe.