FIGURE LEGENDS
Figure 1. Conceptual diagram outlining the ‘contact contingency’
hypothesis. Hypothetical fig wasp relationships and predicted status of
RI inducing Wolbachia according to variation in ecological
contact and evolutionary time since speciation. We predict Wolbachia infection to occur only in community III where species
1 & 2 should harbour unrelated strains. Sister species 3 & 4 are not
in ecological contact as they form separate communities I and II, while
sister-species 5 & 6 in community IV, despite ecological contact, have
had sufficient evolutionary time for alternative (less costly) RI
mechanisms to evolve.
Figure 2. Stylised schematic showing a fig in cross section. Five layers
of ovules are used in our model (white and grey) and no oviposition
occurs in the central lumen (black). Ovule length (and embryo relative
fitness, ω) decreases towards the fig wall (green) where larvae are at
greater risk of parasitism. We use a descriptive model to contrast
inclusive fitness (W) between foundress wasps that do not experience
cytoplasmic incompatibility (wasp 1, blue) and those that do (wasp 2,
orange). Here, in a toy example, each foundress has 10 eggs (open
circles represent viable hybrid eggs with decreased fitness while closed
circles are non-hybrids with full fitness) and we limit oviposition to
two eggs per layer. While CI wasps lay fewer eggs (hybrids are lost to
CI) they do not fill valuable oviposition sites with hybrids of
decreased fitness. Here, the CI wasp gets an inclusive fitness of 3.8
for its seven remaining eggs and the noninfected wasp gets 3.1 for a
full complement of 10 eggs (i.e., by multiplying egg fitness by
oviposition fitness then summing). Inclusive fitness is therefore
greater in wasp 2 despite this fecundity loss, as it lays a higher
number of high fitness eggs in premium oviposition sites. This example
would represent one pixel on the heat maps displayed in Figure 5. Please
see text for further details.
Figure 3. Wolbachia strains mapped along the pollinating wasp
phylogeny. Strain type is indicated by the different colours, with
uninfected individuals in black. For each wasp clade the Ficushost is given.
Figure 4. Wolbachia strain
prediction accuracy by wolPredictor modelling the ‘contact
contingency’ hypothesis across 253 fig wasp pollinator samples at
species clustering thresholds of 2-50 for run name pleio\sout4 .
Accurate positive assignations (orange) are shown above the zero-line
whilst accurate negative assignations (blue) are shown as positive
values below the zero-line.
Figure 5. Heat map evaluation of the ‘oviposition trade-off’ hypothesis.
Comparative inclusive fitness values of fig wasp foundresses across
relative conspecific-heterospecific fitness space at different
population-level frequencies of conspecific mating (between 5-95%)
under alternate scenarios of CI-induced egg mortality (i.e., ‘CI ’
vs. ‘no CI ’). Redder tones (i.e., above zero) indicate relative
conspecific-heterospecific fitness where foundress inclusive fitness is
higher under CI-induced mortality due to preferential oviposition of
higher fitness conspecific offspring despite trade-offs with fecundity
reduction. NB in order to explore all relative fitness space, heatmaps
indicate regions where heterospecific fitness is greater than
conspecific fitness, which will generally be an unrealistic scenario.
Figure S1. Single phylogenies for (a) coxA , (b) fbpA , (c)ftsZ , d) gatB , (e) hcpa and (f) wspincluding sequences generated for this study and all accessions from the
MLST data base, (g) a wsp single gene phylogeny for sequences
generated in this study and (h) a phylogeny derived from the five MLST
genes for sequences from this study only. Colour coding depicts Wolbachia strains red: wspC1, blue: wspC2, purple: wspC3, green
wspC5, yellow: wspC6_1 and orange: wsp6_2.