From what I could trace, the 1940s myths were most likely spread around then (a lot were circa 1930s), just perhaps less commonly. I can definitely attest that at least in the scientific literature then, that was a common enough idea to be inaccurate since, so I’d assume that it was taught to students when approaching biology too. If I’m wrong on this though I can remove this from the site
From what I could trace, the 1940s myths were most likely spread around then (a lot were circa 1930s), just perhaps less commonly. I can definitely attest that at least in the scientific literature then, that was a common enough idea to be inaccurate since, so I’d assume that it was taught to students when approaching biology too. If I’m wrong on this though I can remove this from the site
The human genome one was the one that stood out to me. I’d be curious to see a source from the time if you’ve got one!