What do molecular data such as DNA and protein sequences provide for phylogenetics?

What do molecular data such as DNA and protein sequences provide for phylogenetics?

• A. They reflect relatedness and can be used with molecular clocks to estimate divergence times.
• B. They only indicate current physical appearance.
• C. They have no relevance to phylogeny.
• D. They replace fossil evidence entirely.

Answer: (A)

DNA and protein sequences carry heritable information that accumulates mutations over evolutionary time. By comparing homologous sequences across species, we can measure how similar or different they are, which reflects their relatedness. Those similarities help build phylogenetic trees that depict evolutionary relationships. The molecular clock idea assumes a relatively steady rate of sequence change, so with a known rate or fossil calibration points, we can estimate when lineages diverged. This makes molecular data powerful for phylogenetics, giving both the pattern of relatedness and an estimate of divergence times. They’re not limited to current appearance, and they don’t replace fossil evidence entirely; fossils provide independent calibration points and information about extinct lineages, while molecular data complement that evidence.

DNA and protein sequences carry heritable information that accumulates mutations over evolutionary time. By comparing homologous sequences across species, we can measure how similar or different they are, which reflects their relatedness. Those similarities help build phylogenetic trees that depict evolutionary relationships. The molecular clock idea assumes a relatively steady rate of sequence change, so with a known rate or fossil calibration points, we can estimate when lineages diverged. This makes molecular data powerful for phylogenetics, giving both the pattern of relatedness and an estimate of divergence times. They’re not limited to current appearance, and they don’t replace fossil evidence entirely; fossils provide independent calibration points and information about extinct lineages, while molecular data complement that evidence.