What term refers to identical or similar sequences in nucleic acids that have remained unchanged throughout evolution?

The term that refers to identical or similar sequences in nucleic acids that have remained unchanged throughout evolution is "conserved sequences." These sequences are critical because they often play essential roles in biological functions, and their preservation indicates their importance throughout evolutionary history.

Conserved sequences can be found in different species, suggesting that they have been maintained through generations due to the selective pressures that favor their stability. For example, many regulatory elements and functional domains of proteins are conserved across various organisms, highlighting their crucial roles in genes and cellular processes.

Contrastingly, genetic markers often refer to specific sequences that are associated with particular traits or diseases, rather than sequences preserved over time. Mutated sequences involve changes in the nucleotide structure, which typically occurs less frequently in conserved regions. Homologous sequences, while related and often similar due to a common ancestor, do not necessarily indicate that they have remained unchanged, as they may vary to some extent due to evolutionary divergence.