The exact nature of the first cell is still a subject of scientific debate, but the prevailing hypothesis is that it was a prokaryotic cell.

Here's why:

* Simplicity: Prokaryotes are simpler than eukaryotic cells, lacking a nucleus and other membrane-bound organelles. This makes them more likely to have arisen through simpler, abiotic processes.

* Early Fossils: The oldest known fossils of life are of prokaryotes, dating back to about 3.5 billion years ago.

* Metabolic Diversity: Prokaryotes exhibit a remarkable diversity in their metabolism, including the ability to use a wide range of energy sources. This suggests that early life was likely very adaptable and able to survive in various environments.

It's important to note that this is just a hypothesis, and there are other theories about the origins of life. However, the current evidence points towards prokaryotes as the likely ancestors of all life on Earth.