What does eckels do that has such far-reaching consequences?

Eckels, the protagonist in Ray Bradbury's "A Sound of Thunder," steps off the designated path while on a time-traveling safari to hunt a dinosaur. This seemingly minor action disrupts the ecosystem of the past, leading to significant and unforeseen changes in the present. His choice ultimately alters the course of history, illustrating the delicate balance of time and the profound impact of seemingly trivial actions.