The universality of DNA, the genetic code, ATP use and core metabolism supports common ancestry. Differences in DNA, RNA and protein sequences indicate relatedness and evolutionary divergence.
Proteins play essential roles in all forms of life.
Describe how a protein that is common to many organisms can be used in evolutionary studies.
| a | amino acid sequence of the protein from each organism is compared; |
| b | changes in (base/amino acid) sequence accumulate over time; |
| c | due to mutation; |
| d | positive correlation between number of (base/amino acid) differences between (two) species and time they diverged from a common ancestor OR fewer the (base/amino acid) differences, the less time since diverged from a common ancestor / more closely related; |
| e | cladograms illustrate probable sequence of divergence/evolutionary origins; |
| f | accumulation of mutations can be used as a molecular clock/allows time since evolutionary divergence to be estimated; |