The importance of selection in the evolution of blindness in cavefish

Reed Cartwright, Rachel S. Schwartz, Alexandra L. Merry, Megan M. Howell

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Background: Blindness has evolved repeatedly in cave-dwelling organisms, and many hypotheses have been proposed to explain this observation, including both accumulation of neutral loss-of-function mutations and adaptation to darkness. Investigating the loss of sight in cave dwellers presents an opportunity to understand the operation of fundamental evolutionary processes, including drift, selection, mutation, and migration. Results: Here we model the evolution of blindness in caves. This model captures the interaction of three forces: (1) selection favoring alleles causing blindness, (2) immigration of sightedness alleles from a surface population, and (3) mutations creating blindness alleles. We investigated the dynamics of this model and determined selection-strength thresholds that result in blindness evolving in caves despite immigration of sightedness alleles from the surface. We estimate that the selection coefficient for blindness would need to be at least 0.005 (and maybe as high as 0.5) for blindness to evolve in the model cave-organism, Astyanax mexicanus. Conclusions: Our results indicate that strong selection is required for the evolution of blindness in cave-dwelling organisms, which is consistent with recent work suggesting a high metabolic cost of eye development.

Original languageEnglish (US)
Pages (from-to)1-14
Number of pages14
JournalBMC Evolutionary Biology
Volume17
Issue number1
DOIs
StatePublished - Feb 7 2017

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blindness
caves
cave
allele
alleles
mutation
immigration
organisms
dynamic models
eyes

Keywords

  • Migration-selection balance
  • Models/simulations
  • Mutations
  • Population genetics

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Cite this

The importance of selection in the evolution of blindness in cavefish. / Cartwright, Reed; Schwartz, Rachel S.; Merry, Alexandra L.; Howell, Megan M.

In: BMC Evolutionary Biology, Vol. 17, No. 1, 07.02.2017, p. 1-14.

Research output: Contribution to journalArticle

Cartwright, Reed ; Schwartz, Rachel S. ; Merry, Alexandra L. ; Howell, Megan M. / The importance of selection in the evolution of blindness in cavefish. In: BMC Evolutionary Biology. 2017 ; Vol. 17, No. 1. pp. 1-14.
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