I was curious about the broader interest in various fields of biology over the course of the 20th century, so I looked at Ngram. In case you aren't aware this is a tool that Google set up so you can query the frequency of a particular word or phrase (actually, there's a lot more to it than that, but that's the most elementary use). The limitations here is that these books are all English. Overall, the results surprised me.
Obviously you need to click the image to see the bigger version. But you'll notice that between 1967 and 1974 there was a sharp rise in interest in ecology. I suspect this is the conflation of environmentalism with ecology which only came to the fore with the 1960s counter-culture revolution. Also, while genetics has been slowly gaining over the 20th century, biochemistry has been going into decline after 1985. This is also the same time that physiology began to drop in mentions. Hypotheses?