Classification

• A species is the basic unit of classification. Species are capable of breeding to produce living, fertile offspring.
• Organisms are identified by two names - the generic name and the specific name, in a process known as binomial classification.
• Organisms are identified by two different names under the binomial system - the generic name and the specific name.
• The generic name of an organism appears first, and denotes the genus that an organism belongs to.
• The specific name of an organism appears second, and denotes the species to which the organism belongs.
• Names classified using the binomial system are always written underlined or typed in italics. This indicates that they are scientific names.
• The first letter of the generic name is written in upper case, but the specific name is written in lower case. If the specific name is unknown, we use 'sp' in place of this.
• The grouping of organisms is known as classification, whilst the practice of classification is known as taxonomy.
• There are two main forms of biological classification - artificial classification and phylogenetic classification.
• Artificial classification divides organisms according to observable characteristics such as colour, size etc.
• Artificial characteristics are based on analogous characteristics. These are characteristics that have the same function but different evolutionary origins.
• Phylogenetic classification is based upon the evolutionary relationships between organisms and their ancestors. It classifies species into groups using shared features derived from their ancestors.
• Phylogenetic classification arranges the groups into a hierarchy, in which the groups are contained within larger composite groups with no overlap.