Heredity has devoted the whole of its most recent issue to this topic. Below is a figure from one of the papers in the issue that shows the increase in studies on plasticity since the 1990’s.
“Trends in research output on plasticity. Figure shows number of publications per year up to December 2013. Figure is based on data extracted from a topic search for ‘phenotypic plasticity’ OR ‘developmental plasticity’ OR ‘phenotypic flexibility’ OR ‘behavioural plasticity’ conducted on 21 March 2014 from ISI Web of Science. The literature search yielded 11 822 papers published between 1967 and December 2013. More than 1000 papers are review articles.” Heredity (2015) 115, 276–284