A constraint may be the ability to cooperate in the management of resources. Without said cooperation progress would be difficult if not impossible. The world that the life arose on would need to allow such cooperation.

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(By the way, I hate it that so many papers in the areas of planetary science and geology are not easily available to the dreaded "non-subscribers". It is like they are screaming at me: "YOU CAN'T HANDLE THE TRUTH". Good, I feel better now.)

"Quaerendo inventis"