Current hypotheses to explain genetic chaos under the sea
|Author(s)||Eldon Bjarki1, Riquet Florentine2, 3, Yearsley Jon4, 5, Jollivet Didier6, 7, Broquet Thomas7, 8|
|Affiliation(s)||1 : Museum Nat Kunde Berlin, Leibniz Inst Evolut & Biodiversitatsforsch, D-10115 Berlin, Germany.
2 : Univ Montpellier 2, Pl Eugene Bataillon, F-34095 Montpellier 5, France.
3 : ISEM CNRS, UMR 5554, SMEL, 2 Rue Chantiers, F-34200 Sete, France.
4 : Univ Coll Dublin, Sch Biol & Environm Sci, Dublin 4, Ireland.
5 : Univ Coll Dublin, UCD Earth Inst, Dublin 4, Ireland.
6 : CNRS, Team Adaptat & Biol Invertebrates Extreme Environ, Stn Biol Roscoff, F-29680 Roscoff, France.
7 : Univ Paris 06, Sorbonne Univ, Unite Mixte Rech 7144, F-29680 Roscoff, France.
8 : CNRS, Team Div & Connect Coastal Marine Landscapes, Stn Biol Roscoff, F-29680 Roscoff, France.
|Source||Current Zoology (1674-5507) (Oxford Univ Press), 2016-12 , Vol. 62 , N. 6 , P. 551-566|
|WOS© Times Cited||51|
|Keyword(s)||asynchronous population dynamics, chaotic genetic patchiness, collective dispersal, kin aggregation, larval dispersal, multiple-merger coalescent, sweepstakes reproductive success|
Chaotic genetic patchiness (CGP) refers to surprising patterns of spatial and temporal genetic structure observed in some marine species at a scale where genetic variation should be efficiently homogenized by gene flow via larval dispersal. Here we review and discuss 4 mechanisms that could generate such unexpected patterns: selection, sweepstakes reproductive success, collective dispersal, and temporal shifts in local population dynamics. First, we review examples where genetic differentiation at specific loci was driven by diversifying selection, which was historically the first process invoked to explain CGP. Second, we turn to neutral demographic processes that may drive genome-wide effects, and whose effects on CGP may be enhanced when they act together. We discuss how sweepstakes reproductive success accelerates genetic drift and can thus generate genetic structure, provided that gene flow is not too strong. Collective dispersal is another mechanism whereby genetic structure can be maintained regardless of dispersal intensity, because it may prevent larval cohorts from becoming entirely mixed. Theoretical analyses of both the sweepstakes and the collective dispersal ideas are presented. Finally, we discuss an idea that has received less attention than the other ones just mentioned, namely temporal shifts in local population dynamics.