Primitive in phylogenetics means a character, trait or feature of a lineage or taxon that is inherited from a common ancestor and has undergone little change since. The term in biology contains no judgment involving the sophistication, superiority, value or adaptiveness of a trait. Primitive in biology means only that the trait appeared first in the ancestors and has been passed on largely intact to more recent members of the group.
The Primitiveness of Characters Is Determined By Context
The concept primitive is a based on the phylogenetic position from which it is defined. For example in birds, teeth are primitive since they were inherited from a common ancestor. Among vertebrates, teeth are derived or advanced. Any trait can be both primitive (ancestral) and derived depending on the context in which it is considered.
Species Cannot Be Primitive
The term primitive (or advanced/derived) is not properly used in reference to an organism or species as every species is a mosaic of primitive and derived traits. Humans, for example have large brains (a derived trait) and five fingers (a primitive trait) in our lineage. Species are constantly evolving, so a frog is not more primitive than a human biologically as each has been evolving continuously since each lineage split from their common ancestor.
The term ancestral is often considered a preferable synonym for primitive. The opposite (traits that appear later, have undergone significant evolutionary change, and were thus not directly inherited from a common ancestor) are called derived or advanced. Sometimes the term basal is also used to refer to primitive traits. The technical term plesiomorphic is another synonym for primitive. The corresponding term for derived is apomorphic.
- "Univeristy of California Museum of Paleontology Glossary: Phylogenetics". UCMP Glossary. University of California. Retrieved 7 October 2015.
- Futuyma, Douglas (1998). Evolutionary Biology. Sunderland: Sinauer Associates. ISBN 978-0-87893-189-7.
- Daniel R. Brooks; Deborah A. McLennan (2 May 2002). The Nature of Diversity: An Evolutionary Voyage of Discovery. University of Chicago Press. pp. 33–. ISBN 978-0-226-07590-7.