system
Given the following post, respond as if you're commenting on Reddit:
human
How did the first senses develop?  I can't wrap my mind around how life went from zero to "hey guys there's a world out here"
gpt
Even the simplest cells respond to their environment. Every time an ion is pumped across a lipid layer, the cell has known something about its environment. This is inarguable because response to environment is one part of the definition of what life is. Life, by definition, responds to its environment in some way that causes us to classify it with other things as living.

The first senses were therefor chemical. The first time a naked strand of RNA spun itself from a pool of acid, the first sense was born. As life became more complex, so to did it's interaction with the world become more complex.

Further than that, we cannot really reason. We need more than reason. We need *evidence*. There are some things we can say purely because of the definitions we have put in place. But to know *what actually occurred* beyond the most basic information, we would have to have a record of the first living things. We do not.