Tribe (biology)

In the study of biology, scientists organize all living things into a hierarchy. This system uses different levels called taxonomic ranks. One specific rank is known as a tribe. A tribe serves as a middle grouping in this large system. It sits above the rank of genus. However, it remains below the ranks of subfamily and family.

Taxonomists often divide a tribe into even smaller groups. These smaller subdivisions are called subtribes. To keep the system organized, scientists follow strict rules for writing these names. By convention, all names for ranks above the species level must be capitalized. This includes the names for both the tribe and the subtribe. Using these standard rules helps researchers communicate clearly about life on Earth.

Rules for naming tribes change depending on the type of organism. In zoology, which is the study of animals, tribes use a specific suffix. A suffix is a group of letters added to the end of a name. For animals, the standard ending for a tribe is "-ini". For example, the tribe Bombini includes bumblebees. The tribe Thunnini includes tunas. The tribe Caprini includes goat-antelopes. The tribe Hominini includes hominins.

Zoology also has specific rules for subtribes. An animal subtribe uses the standard ending "-ina". Within the Hominini tribe, there is a subtribe called Hominina. This specific subtribe comprises humans. These endings are very helpful for animal scientists. Within the animal kingdom alone, the endings "-ini", "-ina", and "-inae" are unique. This means if a scientist sees these specific endings, they know exactly which rank they are looking at.

Plants and bacteria follow a different set of naming rules. In botany, the study of plants, tribes use the ending "-eae". An example of this is the tribe Hyacintheae. Another example is the tribe Acalypheae. Plant subtribes use the ending "-inae". For instance, the subtribe Massoniinae is part of the Hyacintheae tribe.

Bacteriology, the study of bacteria, follows the same rules as botany. An example is the tribe Pseudomonadeae, which is based on the genus Pseudomonas.

Identifying a tribe can sometimes be difficult because of these overlapping suffixes. You cannot always identify a tribe just by looking at the end of its name. In animals, the suffixes are very distinct. However, in other groups like algae, the system is more complex. In algae, the suffix "-eae" is used for many different ranks. It can represent a class, such as -phyceae, or a family, such as -aceae. It can even represent a suborder or a subfamily.

Because of this overlap, scientists must work carefully when studying algae. They cannot immediately assume an "-eae" name belongs to a tribe. They must first rule out other possible ranks like class, suborder, family, or subfamily. Only after eliminating those possibilities can they recognize the name as a tribe. This careful process ensures that every living thing is placed in its correct taxonomic position.