On the Evolutionary Advantage of Fitness-Associated Recombination

Abstract

The adaptive value of recombination remains something of a puzzle. One of the basic problems is that recombination not only creates new and advantageous genetic combinations, but also breaks down existing good ones. A negative correlation between the fitness of an individual and its recombination rate would result in prolonged integrity of fitter genetic combinations while enabling less fit ones to produce new combinations. Such a correlation could be mediated by various factors, including stress responses, age, or direct DNA damage. For haploid population models, we show that an allele for such fitness-associated recombination (FAR) can spread both in asexual populations and in populations reproducing sexually at any uniform recombination rate. FAR also carries an advantage for the population as a whole, resulting in a higher average fitness at mutation-selection balance. These results are demonstrated in populations adapting to new environments as well as in well-adapted populations coping with deleterious mutations. Current experimental results providing evidence for the existence of FAR in nature are discussed.

Fitness dependence preserves selection for recombination across diverse mixed mating strategies

“…S4). This is consistent with the analogous results of other studies [8,13] and is expected given that the impact of fitness dependence is limited by the frequency of individuals carrying multiple mutations.…”

“…Alternatively, the theory should take into consideration the essential features of recombination, such as the sensitivity of recombination rate to external (ecological stressor) and/or internal (genotype fitness) conditions. Indeed, models with such condition-dependent recombination suggest that it can be more advantageous than constant recombination under various scenarios [6][7][8][9][10][11][12].…”

Monotonicity of fitness landscapes and mutation rate control

“…Recombination and dispersal are also evolutionary processes that may be under the control of the individual and therefore open to similar effects. Fitness-associated recombination has been demonstrated to be advantageous theoretically [57,58] and identified in biology [59,60]. Similarly, the idea that dispersal associated with low fitness might be advantageous has a basis in simulation of spatially differentiated populations [61,62].…”

Male meiotic recombination rate varies with seasonal temperature fluctuations in wild populations of autotetraploid Arabidopsis arenosa

“…Theoretical studies have made the case that recombination rate plasticity can, in at least some cases, be adaptive (Agrawal et al, 2005 ; Hadany & Beker, 2003 ), though the conditions where it is so, are more restrictive in diploids than in haploids (Agrawal et al, 2005 ). While recombination rate plasticity seems to vary quantitatively, the observation of plasticity in almost all systems suggests there is something truly fundamental about it that may link to the core mechanics of meiosis, which would suggest that rather than “adaptive plasticity”, recombination rate increases may be early symptoms of meiosis beginning to go awry (Morgan et al, 2017 ).…”