Primate Evolution: Gene Loss and Inactivation
Published Online: 15 FEB 2011
Copyright © 2001 John Wiley & Sons, Ltd. All rights reserved.
How to Cite
Satta, Y. 2011. Primate Evolution: Gene Loss and Inactivation. eLS. .
- Published Online: 15 FEB 2011
Pseudogenes are defined as genes that have lost function. However, despite the loss of function, pseudogenes can play an important role in evolution, especially when the environment changes. Owing to some environmental changes in diet or habitat, for example, pseudogenisation may be beneficial rather than deleterious for individual fitness. The human-specific pseudogenes are of particular interest, and more than 100 have been identified. These include olfactory receptors, immune function-related genes and metabolic pathway genes, which seem to be sensitive to environmental conditions. In this article, examples of environment-driven pseudogenisation are presented and the role or significance of the loss-of-function genes in the evolution of primates and humans is discussed.
Functional constraints maintain function of a protein and therefore maintain the conserved way of molecular evolution.
Relaxation of constraints can be achieved in two ways: gene duplication and environmental changes.
Gene duplication provides an extra copy of a functional gene, resulting in the relaxation of a functional constraint to on the gene.
The ‘less-is-more hypothesis’ proposed by Maynard Olson in 1999 suggests loss of function could be an advantage to organisms and also affect phenotypic or physiological changes in evolution.
- environmental changes;
- gene loss/inactivation;
- single-copy pseudogene;
- human evolution