library(Sleuth3)
finches <- case0201
finches$Year <- as.character(finches$Year)
ggplot(finches) + geom_bar(mapping = aes(x = Depth, y = ..prop..,fill = Year),
                           alpha = 0.5, position = "dodge") 

ggplot(finches) + geom_density(mapping = aes(x = Depth,fill = Year), alpha = 0.5)

ggplot(finches) + geom_boxplot(mapping = aes(x = Year, y = Depth))