iiinova — where your digital self keeps evolving

Susana Wadgymar🌿🔬 @smwadgymar.bsky.social · 22/04/2024

Defining fitness in evolutionary ecology A primer for learners at all career stages! w/ @seemasheth.bsky.social, @emjo.bsky.social, Megan DeMarshe, Jill Anderson Please contribute a Primer to this series! Let's make teaching/learning materials more accessible. #Evolution 🌍🌎🌏 #PlantScience 🧪

Hypothetical fitness values for three genotypes measured as survival rate (A), reproductive rate (B; e.g., number of offspring, among individuals that survived, times the percent of seeds that survive), and a combined measure of survival and reproductive rate that can reflect lifetime fitness(C). In each case, absolute fitness refers to the performance of each genotype (e.g., rate of survival, seed production, or lifetime fitness), unadjusted for the success of other genotypes. In contrast, relative fitness is calculated by dividing each genotype’s fitness by the maximum fitness value across genotypes. Note that the rank order of genotype fitness changes depending on the fitness measure under consideration.

Individuals or genotypes that reproduce earlier in life have higher reproductive potential than those that reproduce late (all else being equal). The pink line reflects the reproductive potential of a single individual or genotype that can produce five offspring at an age of 1 yr (as can all of its offspring). Ten years later, it will have produced nearly a million descendants. The teal line represents an individual or genotype with the same reproductive rate but that delays reproduction until 2 yr of age (as do all of its off-spring), producing only 3125 descendants in 10 yr. The gold line demonstrates that the teal individual or genotype would have to produce 25 offspring at age 2 to compensate for the disparity in reproductive output that delayed reproduction can generate.

An approach for identifying alleles associated with fitnessin natural populations of a single species that occur in different environments. First, fitness estimates and sequence data are acquired for plant populations experiencing two different environments. Second, the association between genotype at each locus and fitness estimates is examined, shown here in a Manhattan plot. Statistically significant associations are those that are strong enough to surpass the significance threshold. Lastly, selection coefficients(s) for all variants in each environment are plotted against each other to investigate trade-offs in fitness across environments.

Life cycle diagram for a hypothetical biennial species that germinates and grows vegetatively in one year and flowers and produces seeds in a second year. Repeated surveys of the population allow researchers to estimate the number of juvenile plants (Nj) and flowering plants (Nf) at each time point and to model three vital rates: the survival rate for seeds transitioning into juveniles (Sj), the survival rate for juvenile plants transitioning into flowering plants (Sf), and the number of seeds produced by flowering plants (F).

International Journal of Plant Sciences@ijpsjournal.bsky.social

AOP and OA @ijpsjournal.bsky.social Primers on the Plant Sciences: Defining fitness in evolutionary ecology @smwadgymar.bsky.social, @seemasheth.bsky.social, @emjo.bsky.social, Megan deMarche, Jill Anderson www.journals.uchicago.edu/doi/10.1086/... #PlantScience

02614 26