Yes, if you were to travel back in time 1 billion years and moved a rock just a couple of meters, the world today could potentially be vastly different. This is due to the principle of chaos theory, which suggests that even small changes in initial conditions can lead to significant differences in outcomes over time. This concept is often referred to as the "butterfly effect," where a butterfly flapping its wings in one part of the world can set off a chain of events that leads to a hurricane in another part of the world.
In the scenario you described, moving a rock a couple of meters might seem like an inconsequential action, but it could have far-reaching consequences. Here are a few reasons why:
Ecosystems and Evolution: The movement of a rock could change the microhabitats for various organisms in the area. This change might alter the interactions between species, affecting their survival and reproduction. Over millions of years, these small changes can lead to different evolutionary paths and the emergence of entirely new species.
Geological and Climatic Effects: Moving a rock could disturb the surrounding geology, potentially changing water flow patterns, erosion rates, and soil formations. Such changes can influence local climates and have ripple effects on the broader climate patterns.
Tectonic Activity: The rock you moved might have been acting as a stabilizing element, and its relocation could have consequences for local tectonic activity. This, in turn, can affect the formation of mountains, volcanoes, and even continental drift over geological timescales.
Natural Events: The change in the landscape could impact natural events like the flow of rivers, the formation of lakes, or the occurrence of wildfires. These events can have cascading effects on vegetation, wildlife, and ecosystems.
Human History: The alteration of local geography and ecosystems might affect human migration patterns and settlement in the area. Different civilizations might rise and fall, leading to divergent historical outcomes.
While it's challenging to predict the exact consequences of such a small action with certainty, it illustrates the idea that the Earth's systems are interconnected and highly sensitive to changes. The world today could be vastly different due to the cumulative effects of seemingly insignificant events over billions of years. However, keep in mind that this is a hypothetical scenario since time travel remains a topic of science fiction, and our understanding of the past is based on geological and paleontological evidence.