According to evolutionary theory, all living organisms share what commonality?

The assertion that all living organisms have descended from a common ancestor aligns with the fundamental concept of evolutionary theory. This idea is central to the understanding of the diversity of life on Earth. Charles Darwin's theory of natural selection suggests that species evolve over time through a process of descent with modification, wherein descendants inherit traits from their ancestors while adapting to their environments.

This common ancestry provides a framework for explaining the genetic similarities and differences observed among varying species. For example, the existence of shared genes and molecular structures across diverse organisms supports the notion of a shared lineage. Over billions of years, these descendants have branched out into the multitude of life forms we see today, all tracing back to a singular starting point. Understanding this common descent is crucial for comprehending various biological concepts, including classification, evolutionary relationships, and the processes of speciation.

The other options stem from specific contexts that do not encapsulate the broader principle of common ancestry. While genetic modification can occur in some organisms, it's not a characteristic shared by all. Likewise, the idea that all organisms inhabit the same ecosystem or possess similar physical traits is incorrect; organisms can be vastly different in morphology and can live in entirely separate ecosystems. Thus, the concept of sharing a common ancestor is what unifies all