Final answer:
16S rRNA is used in phylogenetic analysis because it is a highly conserved gene sequence found universally in prokaryotes, which allows for accurate tracing of evolutionary relationships among species.
Step-by-step explanation:
The reason 16S rRNA is commonly used for phylogenetic analysis is that its sequence is highly conserved across diverse species, which makes it an excellent molecular marker. This conservation means that while there are enough variations to distinguish between species, the essential structure of the molecule remains consistent enough to trace evolutionary relationships. Another reason for its wide use is that 16S rRNA is universally present in all prokaryotic organisms and plays a crucial role in the fundamental process of protein synthesis within the ribosome. Moreover, methods like DNA barcoding that utilize rapid sequencing to catalog organisms often rely on conserved gene sequences like those of 16S rRNA, which provide reliable means to compare and contrast genetic material across different species.