Final answer:
Scientists construct the 'tree of life' by comparing a specific RNA sequence present across species, combined with data from fossils, structures, molecules, and DNA analysis to understand the evolutionary relationships of cellular life forms.
Step-by-step explanation:
To understand the evolutionary relationships among diverse organisms, from paramecia and fruit flies to worms and humans, scientists construct a representation known as the "tree of life." This tree illustrates how organisms are related by examining a specific RNA sequence present in all species. It reflects the central dogma of molecular biology, which is the universal genetic code and common mechanisms used by all cellular life forms to store and retrieve genet.
The construction of the tree takes into account data from various sources like fossils, organismal structures, molecules, and extensively DNA analysis. The evolutionary tree is a hypothesis that evolves itself as new information is discovered. Genetics play a crucial role in this process, as studying the genes responsible for development in model organisms like Drosophila and Caenorhabditis elegans helps us understand evolutionary mechanisms.
By tracing pathways from the origin of life to extant species, and vice versa, scientists can uncover relationships and evolutionary history, acknowledging the enormous microbial diversity that represents most of life's evolutionary history.