Benchmark 5A
The Living Environment: Diversity of Life
Grades 9-12, page 105

The degree of kinship between organisms or species can be estimated from the similarity of their DNA sequences, which often closely matches their classification based on anatomical similarities.
 

NSES Content Standard C 
Life Science: Diversity and adaptations of organisms 
Grades 5-8, page 158 
Millions of species of animals, plants, and micro-organisms are alive today. Although different species might look dissimilar, the unity among organisms becomes apparent from an analysis of internal structures, the similarity of their chemical processes, and the evidence of common ancestry. 

NSES Content Standard C 
Life Science: Biological evolution 
Grades 9-12, page 185 
Biological classifications are based on how organisms are related. Organisms are classified into a hierarchy of groups and subgroups based on similarities which reflect their evolutionary relationships. Species is the most fundamental unit of classification.