Stats (or statistics) are the variables that affect the performance of your dinosaur. There are four different types of stats. These stats are:
Speed: Speed determines your dino's top speed, and is the most expensive stat to upgrade.
Acceleration: Acceleration affects the time that it takes your dino to top speed. Acceleration is the cheapest stat to upgrade.
Jump: Jump affects how high your dino can jump. It is the second cheapest stat to upgrade.
Strength: Strength affects how your dino can handle falls, being hit by boulders/meteors, recovery time from objects such as burning pterodactyls and ability to run up hills. the second most expensive stat to upgrade.
Each stat is valuable in their own way. Speed is useful for getting away from doom (for obvious reasons). Acceleration gets you moving faster, so that when hit by a meteor or burning dactyl, you can get back to top speed faster. Jump is a vital stat, because the landscape is full of hills and pits to avoid. And strength is a good way of knocking aside any portable obstacle in your path.
Stats are the only object that DNA can be spent on.