The Field of Bullets hypothesis is an model which states that extinction is non-selective and occurs at random. The analogy is that species are out in a field and being blindly shot at with “bullets,” which are hitting and killing them at random; thus, extinction is due only to stochastic and sporadic effects and events, rather than simply because a species is physically incapable of surviving. The metaphorical field of bullets operates without relation to or prejudice in favor of an organism’s adaptability or fitness. Under this hypothesis, all species are subject to the same probability of extinction regardless of where they originate in taxonomy and what traits they may have which typically buffer against extinction. Perhaps the best example of such randomly occurring extinction is the Cretaceous-Tertiary Extinction that wiped out the dinosaurs, though admittedly this would be an extremely large metaphorical bullet.
Ian Malcolm mentioned the Field of Bullets hypothesis while observing the dinosaurs on Isla Sorna.