  The evolution of vocabulary in academic publishing is characterized via
keyword frequencies recorded the ISI Web of Science citations database. In four
distinct case-studies, evolutionary analysis of keyword frequency change
through time is compared to a model of random copying used as the null
hypothesis, such that selection may be identified against it. The case studies
from the physical sciences indicate greater selection in keyword choice than in
the social sciences. Similar evolutionary analyses can be applied to a wide
range of phenomena; wherever the popularity of multiple items through time has
been recorded, as with web searches, or sales of popular music and books, for
example.
