Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 239
THE WORLD OF BIOLOGICAL RESEARCH
A small insight into the changing dynamics of the life sciences is pro-
vided by observation of the fraction of the total population within each
research area under 34 years of age. This fraction is remarkably close to
21 percent for virtually all research areas, with a few interesting exceptions.
Only 11 percent of those engaged in the study of disease mechanisms are
within this age group, presumably reflecting the long period of residency
training for physicians. In contrast, 23 percent of those in developmental
biology and 28 percent of those in molecular biology and biochemistry were
under the age of 34 at the time ot this survey, ~na~caung anal In one recent
past these two fields, as compared with the other research areas, have be-
come increasingly attractive to young scientists. Only 18 percent of all
those attracted into the life sciences from the physical sciences were within
this age group, indicating that there has been no dramatic upsurge of
interest in the life sciences among young chemists or physicists.
The reverse situation is in accord with the same suggestions. For the
entire population, 18 percent were 50 years of age or older, but only 12
percent of those in molecular biology and biochemistry fell within that age
range, in contrast with 25-28 percent in the areas of disease mechanisms
evolutionary and systematic biology, morphology, and nutrition.
Of some interest are the attributes of the group of investigators origi-
nally trained only as M.D.'s or in the other health professions. They are
older, with only 15 percent under 34 years of age, but 42 percent within
the age span 40-49. Logically, disease mechanisms constitute their prin-
cipal single interest (27 percent of the total), but they are also represented
in every other research area with the exception of systematic biology, major
interests being physiology (22 percent), molecular biology and biochem-
is*y (15 percent), cellular biology (9 percent), and pharmacology (8 per-
cent) .
The 456 women showed only a few distinct tendencies to differ from
the distribution of the men. Women tended to avoid physiology, ecology,
and systematic and behavioral biology, and 28 percent of all female re-
spondents work in molecular biology and biochemistry.
. . .. ~.. .
_
~ · , , ~, ~ 1~
POSTDOCTORAL TRAINING
Prior to World War II, postdoctoral research training experience was a
privilege granted very few young scientists. Fellowships were scarce, and
only the most highly talented could aspire to such opportunity. Since avail-
able research grants were decidedly limited in size, few senior academic
investigators commanded the means to support eligible new M.D.'s or
Ph.D.'s desirous of embarking upon the apprentice training characteristic
239
OCR for page 240
240
THE LIFE SCIENCES
of the postdoctoral experience. That situation no longer obtains. Post-
doctoral experience has become almost the norm rather than the exception,
and we are entirely convinced that this is in the national interest.
However, the situation has given rise to concern among those less closely
associated with research in these disciplines. For example, agencies that
provide support for postdoctoral training are uncertain of its value. Edu-
cational institutions in which postdoctoral fellows abound are uncertain of
their institutional responsibility for this enterprise. Institutions that, per-
haps until 1969, have had difficulty in recruiting sufficient staff to meet
teaching obligations largely the four-year colleges and junior colleges,
but also a significant number of medical schools, as well as industry and
some federal laboratories have complained that the postdoctoral system
is a holdup in the pipeline that, in the steady state, keeps a substantial
number of bright young investigators out of the regular job market. We
appreciate these problems, but consider that the benefits of postdoctoral
education far outweigh these transient difficulties. Let us consider here the
postdoctoral training experience of our responding population of life scien-
tists. In the following chapter there is a summary of the numbers and
activities of postdoctoral fellows in training in 1967-1968, as well as an
analysis of the contribution of postdoctoral education to the operation of
the entire endeavor.
Of the 12,151 investigators in the study, 5,041 had had at least one
postdoctoral appointment, including 1,402 M.D.'s who had had postdoctoral
experience in which research was their major responsibility. Three fourths
of those who had had postdoctoral experience are now in academic life.
Indeed, 45 percent of the 8,143 scientists now employed by universities
had enjoyed postdoctoral experience, compared with 21 percent of the
scientists in industry and 31 percent of those in the federal establishment.
Taken across all disciplines, postdoctoral experience somewhat enhances
the opportunity for employment in the federal government and markedly
enhances the opportunity for employment in the universities. It is our
impression that in universities with major commitments to graduate educa-
tion and research, measured in supporting dollars and number of graduate
students, faculty appointments for individuals who have not had postdoctoral
experience are probably rare indeed. According to a National Academy of
Sciences study of postdoctorals,* 74 percent of all new appointees to the
rank of instructor or assistant professor in 21 departments of biological
sciences in 10 "leading" institutions either came from other university
faculties or had just held postdoctoral appointments.
* The Invisible University: Postdoctoral Education in the United States, Report
of a Study Conducted under the Auspices of the National Research Council, National
Academy of Sciences, Washington, D.C., 1969.
OCR for page 241
THE WORLD OF BIOLOGICAL RESEARCH
However, the trend to postdoctoral education is not universal across all
biological fields. For example, of the 855 individuals with graduate train-
ing in agricultural fields, only 35 had had postdoctoral appointments. In
contrast, postdoctoral training was commonplace among M.D.'s since it
has become the conventional medium for obtaining research training among
this group.
As shown in Table 13, postdoctoral training was less frequent among
botanists (29 percent) than among biochemists (53 percent), with the
other disciplines ranging in between. Postdoctoral training was frequently
taken in fields other than those in which scholars had their initial doctoral
experience. Thus, of the zoologists and botanists who did take postdoctoral
training, less than half did so in zoology and botany departments. Again,
the biochemists appear as the other extreme. Not only did a larger fraction
of biochemists than other life scientists take postdoctoral training, but a
decidedly larger fraction remained within biochemistry for their postdoctoral
experiences. Since an additional 540 individuals who had taken their
original graduate education in fields other than biochemistry sought post-
doctoral training in biochemistry, postdoctoral education is a major aspect
of life in biochemistry departments. Large numbers of those trained in
biochemistry in graduate school later work in other disciplinary areas,
while many individuals enrich their original disciplinary education by a
one- or two-year postdoctoral experience in biochemistry and then, when
they become independent investigators, return to their original disciplines
and research areas or enter yet other research areas.
These data uphold one of the primary arguments in support of the trend
toward postdoctoral experience as a normal component of the education
of those who later will espouse careers in which research is a major activity,
viz., that this constitutes a unique opportunity to broaden one's horizons,
learn new techniques, and become familiar with the style of other sub-
disciplines, while profiting by the examples of different master scientists.
The overall situation is reflected in the totals of Table 13. Of 5,765
Ph.D.'s in this file, 2,395 undertook postdoctoral experience, of whom
1,463, or 61 percent, extended their experience in the same disciplines in
which they had studied in graduate school. But the impression that post-
doctoral experience is a continuation of graduate education in 61 percent
of all cases is misleading, since it is weighted by the fact that more than
half of all of those who did experience this continuation were biochemists.
If the biochemists are excluded, only 50 percent of the remaining scientists
who undertook postdoctoral training did so in their graduate disciplines.
Moreover, such an experience is but rarely a mere continuation of graduate
education. This is borne out by the following consideration: In a subtile
of 3,234 postdoctoral fellows, only 14 percent had taken postdoctoral edu
241
OCR for page 242
THE LIFE SCIENCES
TABLE 13 Postdoctoral Experience of Scientists in a Limited Group of
Biological Disciplines
POSTDOCTORAL
EXPERIENCE
FIELD OF NUMBER IN FIELD OF
GRADUATE OF POSTDOCTORAL GRADUATE
STUDY Ph.D.'s EXPERIENCE STUDY
Number
Percent
Number
Percent
ALL BIOLOGY5,7652,395 411,463 61
Anatomy19674 3730 41
Biochemistry1,834968 53752 77
Botany365108 2940 37
Genetics408157 38116 73
Microbiology1,010359 35198 55
Pharmacology374131 3584 64
Physiology805329 40167 50
Zoology773269 3576 28
Source: Survey of Individual Life Scientists, National Academy of Sciences Committee on Research
in the Life Sciences.
cation in the same university in which they had obtained their doctoral
degrees, and only 6 percent in the same departments that had awarded their
doctoral degrees. This migratory pattern is particularly evident among the
M.D. population. However, about one third of all Ph.D.'s in agriculture
and forestry who undertook their postdoctoral training a rather small
group-did so in their original universities and, indeed, in the departments
that had awarded their degrees. The rather small proportion of students
who remained in the same department for postdoctoral study was almost
twice as great in public universities as in private universities.
In sum, it is clear that the norm for postdoctoral experience, by a wide
measure, consists of apprenticeship to a different set of investigators in an
environment different from that in which graduate education has been com-
pleted. Further, in the experience of our panelists, the current internal
heterogeneity of the classical disciplines assured that even the postdoctoral
trainee who remains within his original discipline is likely to engage in a
problem remote from his graduate research experience. The biochemist
who studied intermediary metabolism may later become preoccupied with
the mechanism of enzyme action; the physiologist who traced neural path-
ways as a graduate student may focus upon ion transport across the nerve
membrane during his postdoctoral years. The botanist who was concerned
with nutritional requirements for plant growth may later become involved
OCR for page 243
THE WORLD OF BIOLOGICAL RESEARCH
in the ecology of a cornfield, while the entomologist concerned with pat-
terns of insect distribution may switch to a study of insect sex attractants.
Intellectual inbreeding is rare in the life sciences community, and the post-
doctoral experience is among the chief means of assuring the hybrid vigor
of the entire enterprise.
A few notes comparing the bioscience subculture with the subcultures of
the physical and social sciences may be warranted. The data in support
of the following statements are derived largely from the recent National
Research Council study of postdoctoral education, The Invisible Univer-
sity.*
In the nation's leading academic institutions, postdoctoral experience
has become the expected prelude to faculty appointment. In recent times,
70 to 80 percent of all initial faculty appointments at such institutions in
physics, in chemistry, in biology departments of faculties of arts and sciences,
and in the preclinical departments of medical schools have been made to
individuals with postdoctoral experience either at the same or at some
other institution. In contrast, initial faculty appointments in the social
sciences, the humanities, and engineenug relatively rarely require post-
doctoral experience. The play of the academic marketplace is such that the
frequency of postdoctoral experience among initial appointees to the faculty
decreases with the general academic status of the institution. Postdoctoral
experience is less frequent among the faculties of "developing" universities,
is rare for scientists who are appointed to the faculties of liberal arts col-
leges, and is. even less common among those who enter industry.
The converse is equally evident; 30 to 40 percent of all relatively young
faculty at all universities who have not had postdoctoral experience feel
this lack in their current professional lives. In all branches of natural
science, promotion up the academic ladder occurs somewhat less rapidly
for those who have not had postdoctoral experience, although this may
reflect similar appraisal of human potential by the committees who select
postdoctoral-fellowship recipients and those who recommend academic
promotions, rather than the intellectual rewards of postdoctoral study.
These trends are undoubtedly enhanced by the advice given to aspiring
scientists by their mentors in graduate school, who strongly urge students
in the natural sciences to undertake postdoctoral experience if they aspire
to academic careers but rarely do so when this is not the case. In general,
such mentors recommend a postdoctoral experience of about two years,
with a specific senior scientist in a field somewhat different from that in
' The Invisible University: Postdoctoral Education in the United States, Report
of a Study Conducted under the Auspices of the National Research Council, National
Academy of Sciences, Washington, D.C., 1969.
243
OCR for page 244
244
THE LIFE SCIENCES
which the student's dissertation research was conducted, thereby broad-
ening his understanding of his discipline. When queried, postdoctoral
students advance the same general purpose as their reason for undertaking
postdoctoral study, but place more emphasis than do their graduate men-
tors upon the acquisition of additional research techniques.
Attempts by statistical means to assess the influence on subsequent scien-
tific productivity of postdoctoral training are not revealing. Differences
among those who took postdoctoral training immediately after graduate
school, those who deferred such training for several years, and those who
had no such training are trivial when measured by counting numbers of
scientific publications, reviews, books written, and similar measures. What
cannot be assessed by this means is the quality of the work or its signifi-
cance to the field. One indicator has been reported in The Invisible Uni-
versity*: the fact that papers published by those who have had postdoctoral
experience are cited about twice as frequently in the Citation Index ~ as
are papers by those who have not had such experience. Statistically, fre-
quency of citation of a paper is some measure of its significance or funda-
mentality. It is our contention that, in all scientific fields, scientific bold-
ness-willingness to venture beyond the frontier or to undertake large and
challenging problems is established relatively early. Certainly, if this is
not encouraged in graduate school or in the immediate postdoctoral years,
it is rarely evident in subsequent careers. But statistical assessment of this
all-important quality is not readily feasible; hence, the enhanced oppor-
tunity to develop such habits of mind is another argument that we would
advance in support of a year or two of postdoctoral study, preferably Ilot
in the same institution or with the same mentor that provided the graduate
experience.
Data purporting to compare the consequences of graduate or post-
doctoral study in the 10 or 20 leading academic institutions with those in
other institutions are probably not completely valid. The selection process
that operates at the level of admission to graduate school and then to post-
doctoral study in the most productive academic laboratories already serves
as a screen almost sufficient to assure the ultimate outcome. It is not
readily possible to distinguish between the consequences of differences in
the quality of the educational experiences in such institutions and the con-
sequences of the quality of the initial human input. Certainly it must be
undeniable that those most highly qualified will benefit most from a stimu
: The Invisible University: Postdoctoral Education in tlze United States, Report
of a Study Conducted under the Auspices of the National Research Council, National
Academy of Sciences, Washington, D.C., 1969.
t Science Citation index; An International Interdisciplinary Index to tlze Literature
of Science. (Published by Institute for Scientific Information, Philadelphia.)
Representative terms from entire chapter:
postdoctoral training
