Protien as genetic inheritance?

[Jikx]

I'm trying to think of a nice topic to do for an essay, it has to be something that was believed to be true, but was proven to be something else due to scientific advances.

I want to do something a bit different from the usual darwin theory / Newton laws. I heard that it was once believed that proteins held the key to inhertitable traits? Anyone have any info on that? Thoughts appreciated.


thanks..

 

[Another God]

Thats actually a really good topic. (Other possible suggestions for topics could be about Phlogiston (old explanation for combustion), or Caloric Fluid (explanation for heat))

As for the proteins as Genetic material, I believe it was the more favoured option over DNA for a long time because the 20 Amino Acids showed the right sort of diversity expected of something like Genetic material. DNA had only 4 bases, and that seemed to small an amount of variety to result in the huge range of phenotypic differences we see.

I know that it can be proven that Proteins aren't the genetic material by radioactivly labelling the amino acids used by a virus to make its proteins, and then allowing one such radioactively labeled virus to infect a cell. Since the virus infects the cell by injecting its genetic material, if proteins were that material, then the radioactively labels should be visible inside the cell. They are not.

Thats my off the head knowledge of the topic. I think Watson or Crick wrote a book about what happened around their discovery of the DOuble Helix structure of DNA, and maybe they go into some back ground history of how why when etc which led up to the victory by DNA...?