Patricia Churchland in her 1996 paper “The Hornswoggle Problem” published in the Journal of Consciousness Studies (scholar link, PDF) writes:
Before 1953, many people believed, on rather good grounds actually, that in order to address the copying problem (transmission of traits from parents to offspring), you would first have to solve the problem of how proteins fold. The former was deemed a much harder problem than the latter, and many scientists believed it was foolhardy to attack the copying problem directly.
Of course, her argument is actually only useful if "many people believed" refers to many biologists believed, which I believe is wha she likely meant.
Her paper is well cited (131 citations) and was one of the earliest and widely read responses to David Chalmers' seminal 1995 paper ("Facing Up to the Problem of Consciousness").
I believe what she wrote could probably be correct, but in any case I am looking for solid evidences (research papers or news articles) that could back this claim (or prove that its false). When I search on Google Scholar with a custom date range, I get irrelevant results.