Summary:
- The first cells were probably no more than organic compounds, such as a simplistic RNA, surrounded by a membrane.
- Over time, as other organic compounds such as DNA and proteins developed, cells also evolved into more complex structures.
- Once a cell was able to be stable, reproduce itself, and pass its genetic information to the next generation, then there was life.
- One cell (or group of cells), called the last universal common ancestor (LUCA), gave rise to all subsequent life on Earth.