What group of organisms is generally classified based on similar hemoglobin sequences?

Mammals are generally classified based on similar hemoglobin sequences because they share a more recent common ancestor that leads to similarities in their hemoglobin molecules, which are proteins responsible for transporting oxygen in the blood. The sequences of these proteins can exhibit notable similarities among different mammalian species, reflecting their evolutionary relationships.

By examining the differences and similarities in hemoglobin sequences, scientists can infer phylogenetic relationships and better understand the evolutionary history of mammals. This type of molecular analysis provides insights into how certain traits have evolved and helps classify organisms within the mammalian group. Other groups, while they may also utilize hemoglobin for oxygen transport, do not share the same degree of sequence similarity in hemoglobin as seen in mammals, making them less suitable for classification based on hemoglobin sequences alone.