Which concept describes the origin of complex cells from simple cells?

The origin of complex cells from simpler ones is best described by the concept of endosymbiosis. This theory posits that eukaryotic cells, which are more complex and contain membrane-bound organelles, evolved through a process whereby certain prokaryotic cells began to live inside one another in a symbiotic relationship. Over time, these internalized prokaryotes became essential components of the host cell, eventually evolving into organelles like mitochondria and chloroplasts.

Endosymbiosis highlights the significant evolutionary transition from simple to complex cellular life, showcasing how cooperation between different organisms can lead to greater biological complexity. This concept is backed by substantial evidence, including the similarities between mitochondria, chloroplasts, and certain prokaryotes in terms of genetic material and structure.

The other concepts do not sufficiently address the specific mechanism through which complex cells arose from simpler ones. Natural selection refers to the process by which certain traits become more common in a population due to advantages they confer, but it does not explain the origins of eukaryotic cells. Convergent evolution describes how unrelated species can evolve similar traits, while adaptive radiation involves the diversification of a common ancestor into a variety of forms adapted to different environments. Neither of