Either Sporoloth Ancient or Thallid Shell-Dweller has at least three spore counters on it, with the other having at least two spore counters on it.
Steps
Activate either Thallid Shell-Dweller or Sporoloth Ancient by removing two spore counters from it, creating a 1/1 Saproling creature token.
When the Saproling enters the battlefield as a Forest land due to Life and Limb, Evolution Sage triggers, putting a spore counter on Thallid Shell-Dweller and Sporoloth Ancient.