The dataset comes from a completely randomized experiment investigating the viability of interspecies and intraspecies mating in two willow beetle species (Phratora vitellinae and Phratora vulgatissima). Females from each species were mated with males of either the same or the other species, giving four treatments with 10 replicates per treatment. The dataset includes the factor Treatment, identifying the mating combination, and the response variable Eggs, which records the number of eggs laid by each female, and is used to compare reproductive outcomes across mating types.
Format
A data frame with 5 variables: DFemale, Treatment, Species, MateType, Eggs.
- DFemale
Factor. Unique identifier for each female subject in the experiment.
- Treatment
Factor. Experimental treatment group assigned to each female.
- Species
Factor. Species designation for each female in the study.
- MateType
Factor. Type of mate provided for each female ("Inter" for interspecific or "Intra" for intraspecific, as relevant).
- Eggs
Integer. Number of eggs laid by each female during the observation period.
Source
Welham, S. J., Gezan, S. A., Clark, S. J., and Mead, A. (2015) Statistical Methods in Biology: Design and analysis of experiments and regression
Peacock, L., Batley, J., Dungait, J. A. J., Barker, J. H. A., Powers, S. J. & Karp, A. (2004). A comparative study of interspecies mating of Phratora vulgatissima and P. vitellinae using behavioural tests and molecular markers. Entomologia Experimentalis et Applicata, 110(3), 231–241.
Examples
fit <- lm(log10(Eggs) ~ Species * MateType, data = beetles)
anova(fit)
#> Analysis of Variance Table
#>
#> Response: log10(Eggs)
#> Df Sum Sq Mean Sq F value Pr(>F)
#> Species 1 0.90307 0.90307 37.9324 4.264e-07 ***
#> MateType 1 0.38073 0.38073 15.9919 0.0003024 ***
#> Species:MateType 1 0.09135 0.09135 3.8369 0.0579165 .
#> Residuals 36 0.85707 0.02381
#> ---
#> Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1