Biology Reference
In-Depth Information
expensive, powerful computers. Mathematical biology remained an ex-
tremely isolated subdiscipline.
44
Those few who used computers for bi-
ology were marginalized as theoreticians in an experiment-dominated
discipline. Margaret Dayhoff at the National Biomedical Research
Foundation (NBRF), for instance, struggled to gain acceptance among
the wider biological community.
45
Goad's position at Los Alamos was
such that he did not require the plaudits of biologists—the prestige of
the laboratory itself, as well as its open-ended mission, allowed him the
freedom to pursue a novel kind of cross-disciplinary work.
In 1974, the Theoretical Division's commitment to the life sciences
was formalized by the formation of a new subdivision: T-10, Theoretical
Biology and Biophysics. The group was formally headed by George I.
Bell, but by this time Goad too was devoting almost all his time to
biological problems. The group worked on problems in immunology,
radiation damage to nucleotides, transport of macromolecules, and hu-
man genetics. The senior scientists saw their role as complementary to
that of the experimenters, building and analyzing mathematical models
of biological systems that could then be tested.
46
It was around this time that Goad and the small group of physi-
cists working with him began to devote more attention to nucleic acid
sequences. For biologists, both protein and nucleotide sequences were
the keys to understanding evolution. Just as morphologists compared
the shapes of the bones or limbs of different species, comparing the
sequence of dog hemoglobin with that of cow hemoglobin, for instance,
allowed inferences about the relatedness and evolutionary trajectories
of dogs and cows. The more sequence that was available, and the more
sensitively it could be compared, the greater insight into evolution could
be gained. In other words, sequence comparison allowed biologists to
study evolutionary dynamics very precisely at the molecular level.
47
Se-
quences were an appealing subject of research for physicists for several
reasons. First, they were understood to be the fundamental building
blocks of biology—studying their structure and function was equivalent
in some sense to studying electrons and quarks in physics. Second, their
discrete code seemed susceptible to the quantitative and computational
tools that physicists had at their disposal. Computers were useful for
processing the large quantities of numerical data from physics experi-
ments and simulations; the growth of nucleotide sequence data offered
similar possibilities for deploying the computer in biology.
48
The T-10
group immediately attempted to formulate sequence analysis as a set
of mathematical problems. Ulam realized quickly that the problem of
