Environment
In this environment agents must gather enough fruit to survive without catching on fire. Their bodies must grow and their brains must learn how best to control their (different) bodies.
Growth and Optimization
Agents begin to emerge but most are not successful: many catch on fire, can't grip the fruit, or are too heavy to move.
Discovery
Successful agents develop useful brain / body pairs that enable them to exploit their unique characteristics. For example, springs are tricky to balance on but help agents to jump high to get the food on the pillars.