Each turn, four cards are drawn and placed face-up in the middle of the table. This is the current resources in the environment. Each player selects one card from their hand and places it face-down in front of them-- a card which they mean to sacrifice to collect resources from the environment and incorporate those aspects into their gene pool.
When every player has put down their cards, the cards are flipped face-up, and play proceeds in Bridge-order (ordered first by numerical value (ace high), then suit (spaces, hearts, diamonds, clubs)). For each card, the corresponding player gets all of the cards in the environment which match his card's face value or suit. These cards are incorporated into the players hand (his gene pool). Then the sacrificed card goes into the environment. When all players have had their turn, all cards remaining in the environment are discarded (die off).
Turns continue, with new environments being formed, until all cards are used. If at any point a player's gene pool runs out of cards, that play is removed from the game (goes extinct). Then each player selects his best 5-card poker hand and the best poker hand wins.