Plot title in R not changing / being edited even with theme plot.title

Question

I'm trying to edit my plot title but no matter what I try for whatever reason it won't actually change. Can someone please help me figure out what's going on? I've also tried adding a different theme before my other theme but that just screws everything else up. I'd appreciate any help! I've attached an image of my code and my plot below. As you will see I've set

theme(plot.title = element_text(face = "bold.italic", colour="black", 
      size = 12, hjust = 0.5) 

but the plot is not reflecting any of those edits.

Code

Answer 1

Never mind I was able to figure it out by introducing the black and white theme and then editing the theme. See code below:

G1B2stodenplot2 <- ggplot(G1B2stodenplot, aes(x=Drought, y=Average_stomatal_density_of_FOV_area, colour=Locality, shape=Locality, group=Locality, shape=Locality)) + 
    geom_errorbar(aes(ymin=Average_stomatal_density_of_FOV_area-se, ymax=Average_stomatal_density_of_FOV_area+se), colour="black", width=.1, position=pd) +
    geom_line(aes(group=Locality, linetype=Locality), show.legend=FALSE, position=pd) + #makes the different lines connecting dots, adds the lines, removes geom_line legend
     geom_point(aes(group=Locality, shape=Locality), size=4, fill="white", position=pd) + 
    #geom_point(position=pd, size=4, shape=21, fill="white") + #21 is filled circle
    scale_colour_manual(name = "Populations",
                      labels = c("Anderson Dam", "Northern Swanton", "Southern Swanton"),
                      values = c("orange", "blue", "brown4")) +   
    scale_shape_manual(name = "Populations",
                     labels = c("Anderson Dam", "Northern Swanton", "Southern Swanton"),
                     values = c(17, 16, 15)) + #shape numbers
    #labs(title="Evolution & Plasticity in Stomatal Density of"~italic("Collinsia multicolor"), x="Years", y="# / mm^2")+
    ggtitle("Evolution in Stomatal Density of"~italic("Collinsia multicolor"))+
    xlab("Years") +
    ylab("# / mm^2") +
    ylim(25, 40)+ #changes y-axis limits
    xlim("Predrought", "Postdrought")+
    theme_bw()+
    theme(plot.title = element_text(colour = "black", size = 14, face = "bold", hjust = 0.5),
          panel.background = element_rect(fill="white"), # Set plot background to white
          panel.grid.major = element_blank(), #remove grid lines
          panel.grid.minor = element_blank(), #remove gride lines
          #panel.border = element_blank(), #remove plot border
          legend.key  = element_rect(fill = "white"), # Set legend item backgrounds to white
          legend.box.background = element_rect(colour = "black"), #set legend border & color black
          legend.title = element_text(hjust = 0.5, color = "black", size = 10, face = "bold"),
          #axis.line.x = element_line(colour = "black", size = 1),  # Add line to x axis
          #axis.line.y = element_line(colour = "black", size = 1),   # Add line to y axis
          axis.text.x = element_text(face="bold", colour="black", size=10),
          axis.text.y = element_text(face="bold", colour="black", size=10),
          axis.title.x = element_text(colour = "black", size = 12, face = "bold"),
          axis.title.y = element_text(colour = "black", size = 12, face = "bold"),
          axis.ticks.length=unit(-0.25, "cm"), #changes tick mark length
          axis.ticks.margin=unit(0.5, "cm") #changes tick mark in or out of plot
          )
G1B2stodenplot2