8

SCIENCE F¢

Wp) vo PERSONALITIES IN MODERN SCIENCE —

EDWARD LAWRIE TATUM

Edward Tatum’s paternal great grand-
father Lawrie Tatum was a Quaker who
settled in the lowa Territory. Besides being
a community leader, he served as an Indian
Agent just after the Civil War, and wrote
a book on the Indians, Qur Red Brothers.
Edward’s maternal grandfather was Ed-
ward David Webb, also a pillar of society,
and once Mayor of Boulder, Colorado. It
was in that city that Lawrie’s grandson
Arthur met Webb’s daughter Mabel. Arthur
was studying at the University of Colorado
at the time. The couple married in Boulder,
and the first of their three children was
Edward (1909).

His father worked at and taught physi-
ology at the universities of Wisconsin, South
Dakota, Pennsylvania, and Chicago. Grow-
ing up in this atmosphere, Edward turned
easily to science. “As far as careers go,”
he says now, “I really was never interested
in anything else.”

In THE Becinninc

He began schooling in the University of
Chicago experimental grade and high
schools and then did two years of college
there. When his father moved on to Wis-
consin as Chairman of the Department of
Pharmacology, Edward followed and com-
pleted his college work there. He had first
been interested in geology, but got his
bachelor’s in chemistry (1930),

Tatum’s parental family had their own
small orchestra, with Edward on the alto
horn, then trumpet, then french horn. He
used to play trumpet with the Wisconsin
football and concert bands, and still retains
vivid memories of standing in the stadium

in downpours or snowstorms, “blowing that

damned horn.”
When the Wisconsin Alumni Research
Foundation began to operate (with funds
gained from sales of its vitamin-D milk-
fortification patents), it supported Edward
Tatum’s first research work. He won his
master’s in 1931, his doctorate (in bio-
chemistry) in 1934, There followed a year
with W.A.R.F., and then the Rockefeller
Foundation Fellowship in organic chemistry
to study at Utrecht, The Netherlands.
Tatum had by this time been well
launched into the exploration of nutritional
requirements of microorganisms. At Wis-
consin, he had shared in the first identifi-
cation of the need of propionic-acid bacteria
for the then recently discovered thiamine.
At Utrecht, he advanced these studies and
learned much about techniques from his

‘contatuinated ihe sterile experiments. Hav-

chief, Fritz Kigl, the discoverer of biotin.

Then a former botanist-become-Droso-
phila-man, George Beadle, who was heading
for Stanford from Harvard, invited Tatum
to join him in his studies of eye pigmen-
tation mechanisms in the flies. Tatum was
signed up by cable. When he and Beadle
began working at Stanford in 1937, neither
kn¥w much about microbial genetics—the
subject that was to earn both of them the
Nobel Prize—although Beadle had special-
ized in corn genetics and been working for
sometime with Drosophila. “For myself,”
Tatum relates, “I honestly knew little about

 

the subject; I’d hardly considered it in my
previous work.”

Many of their inquiries were conducted
with the flies in a sterile environment.
Examination of some anomalous results
showed that a spore-forming bacterium had

ing already shown that lryptophan alone
had no effect on the color of flies’ eyes,
Beadle and Tatum were then able to verify
that the effect did occur when the bacilli
were present, Next, they studied the effect
of injecting individual biosynthetic products
of the bacillus and finally identified the
amino acid kynurenine as the material re-
sponsible for inducing brown eye color in
Drosophila. Subsequent study of uninfected
flies showed that, indeed, the occurrence of
brown eyes results from genetic determina-
tion of biochemical competence for kynure-
nine production, capable of fulfillment in
the presence of adequate supplies of that
substance’s precursors, especially trypto-
phan. The hormone that Beadle and B.
Ephrussi had previously supposed respon-

 
IRTNIGHTLY

October 28, 1964

 

MARINE SNOW conus trom pace 1

granules on which zooplankton can feed.

The Woods Hole investigators, using sea
water that had passed through fine filters
to remove any particulate matter, forced
air through the liquid. This produced a
cloud of fine bubbles and a layer of foam
on the surface. In the process, dissolved
organic matter in the filtered sea water

 

sible for brown eye color in the flies was,
of course, kynurenine.

Beadle and Tatum turned to the study
of microorganisms, in which biosynthetic
mechanisms were easier to observe and
manipulate, and began looking for a suit-
able subject. The tip came from V. 0.
Dodge, then at the Botanical Gardens in
New York. He had made clear that the
fungus Neurospora crassa had a classical
genetic constitution, convenient and unique
reproductive mechanisms, and, otherwise,
that it was “a nice organisin.”

Rewarp

The work that followed—and that of
Lederberg on genetic recombination and
Zinder’s on transduction—received its No-
bel Prize recognition in 1958. Tatum went
to Yale in 1945, as associate and then full
professor of botany. In 1947, he became
Professor of Microbiology, but left in ’48
to return to Stanford. He joined The Rocke-
feller Institute in 1957.

Tatum was married in 1934 and divorced
in 1956. His daughter Margaret is now mar-
ried and the mother of two sons; his other
daughter Barbara is a graduate student in
education, studying the teaching of the
blind. In 1957, Tatum married Viola Kan-
tor. They live in New York, just a few
blocks from his lab at The Rockefeller.
While they don’t take formal vacations,
they usually manage to tack on a few days
of holiday to each of his business trips.
“In recent years, Tatum: has become more
an appreciator than a performer of music—
short spare time is the cause. He’s become
interested in swimming and, even more,
skiing. For a brief period he was hooked
on what he calls “screwball” cars—not
antiques, but odd beasts like the Citroén
2CV.

The Tatums have the odd distinction of
having been among those skiing at Zermatt
during the typhoid epidemic two years ago.
“We never heard a word about the epidemic
until we got back to the States—that’s how
well the Swiss kept their secret. Anyway,”
Tatum says, “we didn’t get typhoid.” Maybe
Salmonella typhosa owes a'debt to the se-
cretive Swiss; if Tatum had laid hold of
that bacterium, who knows what its genetic
makeup might now be. #

was adsorbed on the skins of the bubbles,
forming visible particles.

These non-living organic aggregates,
which Dr. Baylor described to Science
Fortnightly as consisting of phosphates,
nitrates, proteins, polypeptides, and prob-
ably carbohydrates, were then fed to brine
shrimp and copepods. The tiny marine
animals fed on aggregates grew normally,
while controls died within five to eight days.

While the laboratory experiments were
being run, Dr. Riley—in close communica-
tion with Drs. Baylor and Sutcliffe—found
that bubbles were producing these organic
aggregates in the open seas, especially dur-
ing mid-winter storms, which increased bub-
bling.

He also observed that the total quantity
of these aggregates grew as the phytoplank-
ton of any specific area increased. This, he
explained, happens because phytoplankton
themselves secrete much of the organic
matter dissolved in the sea. The balance of
the organic materials comes from decay and
the secretions of zooplankton.

The organic matter aggregated by bub-
bles is the “marine snow” often observed
but never understood by underwater in-
vestigators, Dr. Riley believes.

On the basis of present findings, Dr.
Riley has produced a “community” theory
of evolution, based on the concept that “in-
dividual species adapt toward the form
most suitable for long-term survival of the
community as a whole, even though the
adaptation may sometimes seem to be de-
trimental to the individual species on a
short-term “basis.”

IMPLICATIONS

The secretion by phytoplankton of amino
acids and other organic compounds that
could be used for their own development
would seem to be a distinct disadvantage.
Dr. Riley’s new theory of community evo-
lution, however, proposes that “since the
inaierial secreted can be converted gradu-
ally to particulate food, the process insures
a more stable food supply for the animals.
The latter, in turn, have a distinct pattern
of daily vertical migration that insures uti-
lization of all available food, although they
could feed more abundantly if they could
pause at any level where plants are par-
ticularly abundant.”

Both of these actions, according to Dr.
Riley, help sustain a reservoir of organic
matter that better assures the long-term
survival of the plant-animal community.

The discoveries of Drs. Riley, Sutcliffe,
and Baylor led Dr. P. J. Wangersky, a
marine biologist at Yale University, to sug-
gest that this mechanism of adsorption by
bubbling may have been a key step in the
evolution of life from nonliving materials. #