Prokaryotic cells evolved first. These simple, single-celled organisms are believed to have appeared around 3.5 billion years ago. Prokaryotic cells, which include bacteria and archaea, lack a nucleus and other membrane-bound organelles, making them relatively simple in structure compared to eukaryotic cells.
Eukaryotic cells, on the other hand, emerged later in the evolutionary timeline, estimated to be around 1.5 billion years ago. They have a more complex structure, characterized by the presence of a nucleus and various organelles that perform specific functions. This evolution marked a significant step in the development of more complex life forms, including plants, animals, and fungi.
In summary, the simplicity and adaptability of prokaryotic cells allowed them to dominate early Earth, paving the way for the eventual emergence of eukaryotic cells and the diverse array of life we see today.