What do proteins constructed from a higher number of similar amino acids indicate?

Proteins constructed from a higher number of similar amino acids indicate that the organisms are closely related because amino acids are the building blocks of proteins, which are encoded by the genetic information of an organism. When different organisms share a higher proportion of similar amino acids in their proteins, it suggests that they have a more recent common ancestor. This is due to the fact that evolutionary processes tend to result in similar genetic sequences being inherited by related species. Such similarities in protein structure often reflect the underlying genetic similarities, supporting the idea of closer evolutionary relationships between the organisms in question.

In contrast, greater differences in the sequence of amino acids typically point towards more divergent evolutionary paths and indicate a more distant relationship. Sharing similar habitats does not necessarily correlate with genetic or evolutionary relationships, as organisms in similar environments can be quite distantly related. Additionally, significant genetic variation among organisms can lead to diverse protein structures, which would not indicate closeness in terms of evolutionary relationships.