I want to know the answer to the following question:
Which scientist's study theorized that the idea of Darwin's work being delayed dates to the 1940s?
All the background I'm provided with is that "A more recent study by science historian John van Wyhe has determined that the idea that Darwin delayed publication only dates back to the 1940s, and Darwin's contemporaries thought the time he took was reasonable.". Is that enough to answer the question?