Interview with David Baltimore - Caltech Oral Histories

Baltimore-46
appears in Howard’s PhD thesis, in 1959. Howard then went off to the University of Wisconsin
as an assistant professor, rose to be a full professor, stayed there his whole career. Over the ten
years between 1960 and 1970, he tried to find a killer experiment that would prove he was right.
And he couldn’t find it—a definitive experiment. He worked with drugs, he worked with
radiation; he worked with radioactivity. He did everything we knew how to do at the time—
hybridization. And none of it was convincing to nonbelievers in the scientific community, and
there were almost no believers, except for Howard. Nobody thought that RNA would be copied
into DNA. That notion was— It wasn’t exactly anathema, but Crick had said, famously, that
the central dogma of biology was that DNA made RNA made protein, and it still is the central
dogma of biology. The fact that RNA can be copied into DNA, which we now know so very
well, doesn’t change the fact that the flow of information in a cell, be it a person or an animal or
a bacterium, is from DNA to RNA to protein. So that was ingrained in people’s minds. This
was still early days in molecular biological thinking, so dogmas had an important role; they
guided people’s thinking. That’s what people thought about.
Howard became increasingly convinced that RNA made DNA, but he couldn’t find a way
to prove it. He published a number of papers on it; he talked about it at meetings. He also did
other work, but in fact he was viewed as a bit of a heretic in this thing because he was so
persistently trying to find a way to prove it.
So in 1969 I began to see a way to test it. I was aware of what he was doing. I was in
virology; I taught virology. I didn’t do anything with cancer-inducing viruses, but I was
interested in the whole issue of cancer and viruses, actually from way back. Through all of this
period, although I had known Howard at the Jackson Lab—I think we talked about that—I didn’t
see Howard much. He was stuck in Wisconsin; he wasn’t invited many places, because the big
thing he was doing was something that most people just didn’t believe in, and they didn’t want to
hear any more about it; and he was pretty monomaniacal in his approach to it. And my own
career was going very well; I was working on poliovirus all that time and became moderately
well known for it. So, no, Howard and I didn’t have much communication through this period. I
remember once seeing him—and only once in that time—and seeing his performance, if you
wish, about this issue. It was probably around 1967, in Issaquah, Washington.