Instead of Unique Factions per say, the Colony instead gains Evolution Upgrades. One can only choose one evolution branch for that match/mission and locks out the rest. Choosing an Evolution grants that Colony New Units available only to that selected Branch.

Controller Evolution:
Controller Evolution modifies the Colony's Gene Set to include Breeds which hinder or cause chaos in the enemy ranks.

Psionic Ant (Support Crowd Control Infantry)
Tesla Ant (Debuffer & Assault Vehicle)

Brute Evolution:
Brute Evolution modifies the Colony's Gene Set to include new Breeds which as their namesake implies, Increase Survivability as well as support their Units.

Gripper Ant (Debuffer & Light Assault Infantry)
Ravager Ant (Support Buffer & Heavy Assault Vehicle)

Volatility Evolution:
The Volatility Evolution modifies the Colony's Gene Set to include new Breeds which increase the Colony's Firepower & Efficiency in Battle.

Vermin Ant (Assault Infantry)
Herald Ant (Support Buffer & Light Assault Vehicles)