Muller’s ratchet and the pattern of variation at a neutral locus

• Author(s): Gordo, I. ; Navarro, A. ; Charlesworth, B.
• Date: 2002
• Persistent ID: http://hdl.handle.net/10400.7/96
• Origin: ARCA - Access to Research and Communication Annals
• Subject(s): BACKGROUND SELECTION; ASEXUAL POPULATIONS; STATISTICAL TESTS; Y-CHROMOSOMES; DELETERIOUS MUTATIONS; DOSAGE COMPENSATION; MOLECULAR EVOLUTION; DNA POLYMORPHISM; DEGENERATION; ACCUMULATION
• Document Type: Article
• Language: English

Description

The levels and patterns of variation at a neutral locus are analyzed in a haploid asexual population Undergoing accumulation of deleterious mutations due to Muller's ratchet. We find that the movement Of Muller's ratchet can be associated with a considerable reduction in genetic diversity below classical neutral expectation. The extent to which variability is reduced is a function Of the deleterious initiation rate, the fitness effects of the Imitations, and the population size. Approximate analytical expressions for the expected genetic diversity are compared with simulation results under two different models of deleterious imitations: a model where all deleterious imitations have equal effects and a model where there are two classes of deleterious imitations. We also find that Muller's ratchet can produce a considerable distortion in the neutral frequency spectrum toward an excess of rare variants.