Why does sex exist? Because combinations multiply possibilities faster than mutations can destroy them. Run two populations side by side and watch the math prove it.
Left: asexual clones with occasional point mutations. Right: sexually reproducing population with free recombination across n loci each generation. Adjust the sliders and advance generation by generation.
Two parent chromosomes shown as colored locus bars. Click on either parent strip to add or remove crossover points (white tick marks). The offspring strip is generated live, alternating segments between parents at each crossover. More crossover points = more offspring variants.
Click on Parent A or Parent B strips to toggle crossover points. Crossovers determine where segments switch between parents.
Unique genotypes as a fraction of population size (0 = everyone identical, 1 = full saturation). The sexual population fills genotype space; the clonal population stays a single point, inching forward only by rare mutation.
Every claim in this exhibit is grounded in peer-reviewed population genetics and evolutionary biology.
Comprehensive review of why sex persists despite the two-fold cost, covering the Red Queen hypothesis, Muller's Ratchet, and the combinatorial advantages of recombination.
doi:10.1086/605284Bell's landmark work documenting the diversity of reproductive modes across eukaryotic life and building the empirical case for the pluralist view of sex evolution. University of California Press.
UC Press catalogueOriginal formulation of Muller's Ratchet: asexual populations accumulate deleterious mutations irreversibly because recombination cannot reassemble low-mutation genotypes. Mutation Research, 1:2–9.
doi:10.1016/0027-5107(64)90047-8Classic empirical and theoretical demonstration that host–parasite co-evolution selects for sexual reproduction because diversity denies parasites a stable target. PNAS 87:3566–3573.
doi:10.1073/pnas.87.9.3566Standard graduate textbook covering meiosis, free recombination, linkage disequilibrium, and the population genetics of sexual vs. asexual reproduction. Sinauer/Oxford University Press, 2017.
OUP catalogue