Overall I found metrics for 11,036 papers.
I calculated the 2011 PLOS ONE impact factor as 2.647
Here's a histogram of all citations.
Overall there doesn't seem to be much difference between categories.
tapply(lev1df$cites, lev1df$category, mean)
## Biology and life sciences Computer and information sciences
## 2.664 2.795
## Earth sciences Engineering and technology
## 2.543 2.216
## Environmental sciences and ecology Medicine and health sciences
## 2.745 2.833
## Physical sciences Research and analysis methods
## 2.432 2.644
## Science policy Social sciences
## 1.697 2.413
Even looking more closely at the small scale factors, we see not much difference between eco and evo related papers.
ecoplos <- lev2df[grep("ecology", lev2df$cat), ]
mean(ecoplos$cites)
## [1] 2.868
evoplos <- lev2df[grep("evolut", lev2df$cat), ]
mean(evoplos$cites)
## [1] 2.739