RT Journal Article
SR Electronic
T1 Strong Selection is Necessary for Evolution of Blindness in Cave Dwellers
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 031872
DO 10.1101/031872
A1 Reed A. Cartwright
A1 Rachel S. Schwartz
A1 Alexandra L. Merry
A1 Megan M. Howell
YR 2016
UL http://biorxiv.org/content/early/2016/06/09/031872.abstract
AB Blindness has evolved repeatedly in cave-dwelling organisms, and 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. The observation of blind organisms has prompted many hypotheses for their blindness, including both accumulation of neutral, loss-of-function mutations and adaptation to darkness. 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) loss-of-function 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. 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.