40s and 50s Memories
he may have been exaggerating!
My post-King's life:
Three chance events while a botany student at
Imperial College, London determined the rest
of my life, and set it on its charmed course. The
first was reading "Fleas, Flukes and Cuckoos"
by Miriam Rothschild and Theresa Clay.
Miriam Rothschild was a member of the famous
Rothschild family of bankers and biologists who
established the gracious Tring Museum. The
book describes the fascinating co-evolution of
different fleas, lice and worms and their bird and
mammal hosts. It shows how a combined study
of hosts and their parasites greatly enhances
understanding of the evolution of either for
"Nothing in biology makes sense except in the
light of evolution" (Dobzhansky, 1973). The
second event was attending a student seminar
given by Kenneth Smith of the University of
Cambridge, the leading describer of the diverse
viruses of plants and insects. It struck me, at the
time, that the study of viruses would benefit from
the Rothschild/Clay approach. So when Phillip
Gregory, our Professor, asked me whether,
after graduating, I'd like to do research, and if
so, on what, I blurted out that I'd like to find out
where viruses came from, and when. He told
me that it was an admirable but unachievable
aim, but nonetheless took me to Rothamsted
Experimental Station to meet Fred Bawden, the
world's leading plant virologist at the time, and
a Ph.D. scholarship was organised.
Viruses are subcellular organisms that spread
between, and replicate in, cellular organisms
such as plants, animals and bacteria. They are
just a different way genes make a living. We
are mostly aware of those that cause various
human diseases, such as 'flu and chicken pox,
but others cause diseases of plants, insects,
bacteria and fungi (such as mushrooms),
indeed wherever they have been sought,
viruses or their footprints have been found.
For example, one fifth of human genes are
the defective remains of viruses, and it is not
widely realized that most of the phosphate in
the sea cycles daily through the DNA of viruses
- phytoplankton mop up the phosphate in the
sea, they are eaten by amoebae, which in turn
are infected and lysed by viruses, releasing the
phosphate. Viruses replicate in the cells of their hosts using the host's metabolic machinery,
so they are obligate parasites. They produce
characteristic particles that infect virus-free
host cells. The symptoms they cause aid the
spread of particles to uninfected hosts to start
a new cycle of infection. Some viruses, such
as 'flu are directly contagious and spread in
droplets, but others require specific vectors,
such as mosquitoes or aphids.
Back in the 1950s, when I started research,
the study of viruses was still in its early stages.
Their novelty and small size had been first
discovered at the turn of the century, but their
minute particles were not seen until electron
microscopes first became available in the
1940s. There was much discussion in those
days whether viruses were 'living' or 'dead', as
their particles, which were of uniform shapes and
sizes, could be crystallized like chemicals! To
understand their origins and evolution seemed a
distant dream, however the study of viruses has
many experimental advantages and, as most of
the major advances of molecular biology have
involved work with viruses, information about
them has accumulated fast. As a result, during
my working life, the dream has become a reality,
and we now have a clear understanding of how
viruses evolve, and even their ancient origins
can be sensibly guessed.
At Rothamsted we all worked on the biology and
ecology of viruses important to agriculture; my
niche was the viruses of legumes, sugar beet
and honey bees. It was a very interesting place
to work as it is the oldest agricultural research
institute in the world, founded in 1843 by Sir
John Lawes in the grounds of his 16th century
manor. He started the famous Broadbalk and
Park Grass fertilizer experiments there in the
1850s, superphosphate was invented there,
most of the basic work on pyrethroid insecticides
was done there, and the Statistics Department
had one of the first "electronic computers"
operated by switches and plug boards; it
occupied a whole large room, and when finally
switched off in 1970, it went straight to the
British Museum!!! As Rothamsted was close to
London, one never knew who one might meet
when all the staff assembled at 'Green Gables'
every afternoon for tea. One afternoon I found
myself next to Tenzing Norgay of Everest fame
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