Adv Physiol Educ 29: 3–10, 2005;
doi:10.1152/advan.00028.2004.
A Personal View
Aims of undergraduate physiology education: a view from the University
of Chicago
Martin E. Feder
Department of Organismal Biology & Anatomy, The Committees on Evolutionary Biology, Genetics,
and Molecular Medicine, and The College, The University of Chicago, Chicago, Illinois
Received 30 June 2004; accepted in final form 18 August 2004
liberal arts education; sciomics
I. A PECULIAR INSTITUTION
The University of Chicago is peculiarly introspective. A
colleague once remarked, “If every university taught basket
weaving, The University of Chicago would instead teach the
theory of basket weaving.” A proposal to increase the enrollment of the undergraduate College resulted in a formal Faculty
Committee for a Year of Reflection (5a), which reported, in
part:
We at the University take pride in our ability to explain
ourselves, to give the reasons for why we are investigating what
we are investigating, and for the manner and means we are
using to do so. The fact that we spend so much time explaining
ourselves to one another, often across barriers that loom larger
elsewhere than here, helps explain why the question of intellectual discipline is always in play. We are concerned to know
when good work is good because of intellectual talent and
when because of transmissible method. . . . The other side of
this coin–our preoccupation with explaining ourselves to ourselves–is a conspicuous emphasis on the question as a form of
discourse. Chicago has developed a celebrated–some would
say notorious–brand of academic civility. It is a place in which
one is always in principle allowed to pose the hardest question
possible–of a student, a teacher, or a colleague–and feel entitled
to expect gratitude rather than resentment for one’s effort. The
trait is frequently noted (not always approvingly) by scholars
from other institutions who visit us. . . . For example, when
Weber wrote about the scholar’s obsession with devil’s advocacy, he could have been talking about the University of
Chicago.
Address for reprint requests and other correspondence: M. E. Feder, Dept. of
Organismal Biology and Anatomy, The Univ. of Chicago, 1027 E. 57th St.,
Chicago, IL 60637 (E-mail: [email protected]).
Undergraduate education does not escape this introspection
here. Since 1962, the signature event in the entering student’s
orientation has been the Aims of Education address, which a
senior professor delivers formally from the pulpit of the University’s chapel. It endeavors to explain what a liberal arts
education should be about and what its goals should be. A glib
summary of these sometimes ponderous and abstract addresses
is: “A liberal arts education teaches you to read the New York
Times intelligently.”
In this tradition, I ask several questions: What are the aims
of physiology education at the undergraduate level (or, more
generally, other than the training of excellent clinicians)? What
are the essential core ideas or concepts that it strives to
communicate? Or, more broadly, what about physiology is so
important that it should remain a prominent component of
undergraduate training in the life sciences, in science in general, and in the liberal arts? This last question is also now being
asked by a growing number of educators, trainers of biomedical scientists and physicians, and even by national commissions (13). The answer is not always pleasing to physiologists
(18). My glib answer is, “It teaches you to read Science and
Nature intelligently.” Or, less glibly, “If science is ‘a way of
knowing’ (12), then physiology is a way, if not a superior way,
of knowing science.”
II. WHAT ARE THE ESSENTIAL CORE IDEAS OR CONCEPTS
THAT AN UNDERGRADUATE PHYSIOLOGY EDUCATION
MIGHT STRIVE TO COMMUNICATE?
If “God is in the details” (11), physiologists are among the
most religious of educators, because communicating the elegance of physiological mechanisms usually emerges from the
detailed explication of the inner workings of molecules, cells,
1043-4046/05 $8.00 Copyright © 2005 The American Physiological Society
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Feder, Martin E. Aims of undergraduate physiology education: a view
from the University of Chicago. Adv Physiol Educ 29: 3–10, 2005;
doi:10.1152/advan.00028.2004.—Physiology may play an important, if not
essential role, in a liberal arts education because it provides a context for
integrating information and concepts from diverse biological and extra-biological disciplines. Instructors of physiology may aid in fulfilling this role by
clarifying the core concepts that physiological details exemplify. As an example, presented here are the core principles that are the basis for an undergraduate
physiology course taught at the University of Chicago. The first of these is:
Evolution has resulted in organisms comprising mechanisms for maintenance,
growth, and reproduction, despite perturbations of the internal and external
environment. Such principles necessitate a coupling of physiology to diverse
disciplines (i.e., “sciomics”) and provide a basis for integrating discoveries in
other disciplines.
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AIMS OF PHYSIOLOGY EDUCATION
1. Evolution [2] has resulted in organisms [5] comprising [6]
mechanisms for maintenance, growth, and reproduction [7]
despite perturbations of the internal and external environment [8].
2. Organic evolution (as opposed to a human engineering
process or its counterpart) is responsible for extant physiological mechanisms and explains the unity, diversity, and
idiosyncrasy evident in these mechanisms. “Nothing in
biology makes sense except in light of evolution” (5), and
physiology is no exception. Evolution is “descent [3] with
modification [4]” (4).
3. Descent. How and why humans and nonhuman animals
work the way they do is largely because these animals have
inherited their physiological workings from their parents
(and in turn from their parents’ ancestors).
A. Many aspects of physiology are similar if not uniform
in diverse organisms. The most parsimonious explanation of this similarity/unity is that the diverse organisms have evolved from common ancestors, if not a
common ancestor.
B. Point [3A] is the rationale for comparative physiology;
i.e., study of one taxon can elucidate the physiology of
another.
C. Descent implies that physiological mechanisms can
and must be encodable in nucleic acid sequence and/or
be heritable via some other mechanism (e.g., gene
imprinting, other epigenetic mechanism, parasitic or
symbiotic vectors).
i. This ultimately is the rationale for functional and
physiological genomics.
ii. Genetic mechanisms, including chromatin, chromosomes, segregation and independent assortment, linkage and recombination, transposition,
expression, and splicing, among many others, both
potentiate and constrain physiological diversification and innovation. Understanding of physiology
is not divorceable from understanding of genetics.
4. Modification. Natural and sexual selection are potent
mechanisms that can modify or maintain physiological
mechanisms. These mechanisms result in change (or stasis)
that maximizes Darwinian fitness, either in general or in
specific environments/contexts, i.e., adaptation.
A. Diversity in physiological mechanism can be an outcome of selection in different environments and circumstances.
B. Selection acts on preexisting, often random heritable
variation [3]. Thus
i. selection can and will yield multiple physiological
mechanisms as a function of what variation happens to preexist at its start;
ii. comparison of traits modified by selection can
reveal multiple and independent solutions* to any
given physiological problem;* and
iii. selection cannot act unless heritable variation is
present and can act only on what variation is
present. Physiological mechanisms that an engineer might envision cannot arise without corresponding heritable variation.
C. Other evolutionary processes can also modify traits,
and need to be considered as sources of physiological
diversity.
D. Selection operates in the context of genetics [3C] and
demography.
5. The organism is an essential aspect of physiology.*
A. To paraphrase Knut Schmidt-Nielsen (17), physiology
is the study of how organisms work or succeed, which
requires a heuristic metric of when organisms are/are
not working well or sufficiently. For wild organisms,
metrics include Darwinian fitness, evolutionary persistence, ecological breadth, and population size. For
humans, metrics include health, longevity, physical
fitness, and role in society. For nonhuman organisms
of economic significance, metrics include productivity
and value.
B. What matters for success [5A] is that the entire organism functions well or sufficiently. Absent such function, successful function of isolated components of
organisms is inconsequential.
i. This ([5B]) necessitates successful communication
among, coordination of, and integration of organismal components.
ii. The goal of physiology as a science is to explain
successful [5A] organismal [5B] function or its
lack. For example, physiology provides an understanding of what may go awry in disease, and what
compensatory mechanisms may be called into play
to deal with disturbances.
C. Maintenance, growth, and reproduction are each essential functions of successful [5A] organisms.
*Evolution does not invent or discover solutions to problems in the sense
that human engineers might. More accurately, selection results in the proliferation of alternative genotypes, themselves arising from the preexisting
genome by essentially random processes that encode enhanced inclusive
fitness. Nonetheless, teleonomy (in this case, presenting physiological mechanisms as evolution’s solutions to problems or challenges) is a useful heuristic
device. Throughout the manuscript, asterisks signify the use of this device.
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tissues, organs, and organ systems. Such detailed explication,
however, is seldom in plain language. A “devil’s definition” of
physiology, as I tell undergraduates, is “that branch of science
dedicated to the proliferation of terminology.” Coupled with
the explosion of knowledge in physiology, the result is ever
more lengthy physiology texts and a growing discrepancy
between the total duration of undergraduate physiology courses
and the material they “must” contain. Such education can be
superb in presenting trees (i.e., individual facts and findings)
but can obscure forests if not entire landscapes (i.e., general
principals and themes). But what of the forests and landscapes
themselves? There is no one correct answer. Answers are
highly individualized and largely an artifact of one’s own
education and career in physiology. Thus what follows is
literally the personal view that informs one undergraduate
course in physiology at the University of Chicago. As appropriate for Chicago’s urban landscape and winter weather, it is
depauperate of leaves and trees (i.e., mention of specific
physiological mechanisms and systems), leaving the forest and
landscape unobscured. Alternatively, if the typical physiology
text is a comprehensive grammar, think of the following as
modeled after Strunk and White (19). [Note: Numbers in bold
and brackets refer to prior or subsequent points in this section.]
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AIMS OF PHYSIOLOGY EDUCATION
Fig. 1. Some categories of mass and energy/force “species” of relevance to
physiology. Within each category fall the individual species. For example,
within ions and salts are Na⫹, K⫹, Ca2⫹, Cl⫺, HCO⫺
3 , etc.
isolate themselves from their environment and be successful [5A].
B. Environment varies in its content of mass and energy.
This variation often exceeds the range of energy and
mass abundances in which physiological mechanisms
function well (if at all) [7D].
C. Organisms must therefore exchange both mass and
energy with the environment but avoid equilibration
with harmful or lethal environments.
9. Exchange and equilibration among compartments obey
simple rules (Fig. 2).
A. The amount of mass and energy in an organism or
compartment thereof (whether adequate, too much, or
too little) is a joint function of how much is present to
begin with, the rate at which it is lost, and the rate at
which it is gained.
i. When loss and gain/production are equal, no
change occurs.
ii. When loss and gain/production are unequal, the
amount of mass and/or energy changes correspondingly.
B. Loss and/or gain (i.e., exchange) is by a limited
number of physical/chemical processes, which can
be understood from first principles of chemistry and
physics. Most such processes are proportional to the
product of the gradient in mass and/or energy “concentration” (fraction of capacity) between exchanging
compartments and the conductance of mass and/or energy (Fig. 2).
C. Because of [9A], organisms can, in principle, adjust
loss and/or gain of mass and energy to maintain mass
and energy within a compartment at constant levels or
at whatever level is appropriate for maintenance,
growth, and reproduction.
i. Such a regulated state is termed homeostasis.
ii. Mechanisms for adjusting loss and/or gain of mass
and energy involve manipulating the physical/
chemical processes through which loss and/or gain
of mass and energy occur [9B]. These processes,
however, may themselves consume mass and/or
energy and result in reaction products.
iii. Organisms exploit variants of a small number of
control algorithms to set rates of loss and gain/
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D. Organisms comprise physiological mechanisms or machineries for accomplishing maintenance, growth, and
reproduction and hence, organismal success.
6. The organism is at the midpoint of a scale of biological
organization.
A. Levels of biological organization, from “lowest” [7] to
“highest”: biological molecules 3 molecular complexes 3 organelles 3 cells 3 tissues 3 organs 3
organ systems 3 organisms 3 populations 3 communities 3 ecosystems.
B. Every level finds its mechanism at lower levels of
biological organization and its significance at higher
levels of biological organization (2). Any complete
scientific explanation in physiology will therefore ultimately involve every level of biology.
C. Each level exhibits functional attributes (“emergent
properties”) not apparent in the levels below it [12D].
That is, the whole is greater than the sum of its parts.
7. Mechanisms [5D] for maintenance, growth, and reproduction require matter and energy (Fig. 1).
A. Lowest level substances (e.g., proteins, carbohydrates,
nucleic acids, lipids), which all mechanisms ultimately
comprise, are themselves matter/mass.
B. Lowest level substances (e.g., proteins, carbohydrates,
nucleic acids, lipids) typically require energy for their
acquisition, biosynthesis, and maintenance, and higherlevel mechanisms also require energy for their assembly and maintenance. Most also require energy for
their function.
i. Laws of thermodynamics pertain to living systems. Thus, for example, energy is required to
maintain order and preserve information.
ii. Most mechanisms at some level have their basis in
energy-consuming biochemical reactions.
C. Because of [7Bi] and [7Bii], most mechanisms require
catalysis at physiological temperatures. Biological catalysis typically finds its basis in the conformational
change of proteins (i.e., enzymes), which requires that
the proteins be conformationally flexible.
D. Because of [7B] and [7C], many mechanisms function
well (if at all) only within a relatively narrow range of
energy and mass abundances.
E. Many of the required biochemical reactions [7Bii],
being chemical equilibrium reactions, are inhibited by
the accumulation of their products, and hence require
removal of their products to proceed.
F. Biological reactants and reaction products are physically and chemically diverse, necessitating correspondingly diverse regulatory systems, supply and
storage systems for reactants, reactors, catalysts and
cofactors, and storage and disposal systems for reaction products. Nonetheless, these reactions are coupled, necessitating integration of their regulation. The
necessity to couple systems through key intermediates,
however, also confers fragility (3) [see also 12Dii].
8. Environment.
A. Environment is the source of required mass and energy
[7, A and B] and the sink for reaction products [7E],
necessitating exchange of mass and energy between all
organisms and their environment. Organisms cannot
5
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AIMS OF PHYSIOLOGY EDUCATION
production to achieve homeostasis. These necessitate command/control of mechanisms that adjust
loss/gain.
iv. These mechanisms cumulatively are effective in
minimizing/negating environmental perturbation,
within limits.
D. Fluxes of particular “species” of mass and energy, and
mass and energy in general, are not independent of one
another, but are coupled. A challenge for organisms
that evolution has met* is simultaneously to increase
fluxes for some mass or energy species when and
where warranted, to decrease fluxes for some mass or
energy species when and where warranted, and to
maintain constant fluxes for some mass or energy
species when and where warranted despite the coupling of all these fluxes (Fig. 3).
10. Physical mechanisms of exchange through surfaces (e.g.,
diffusion and like processes) can be manipulated and exploited* according to their underlying principles.
A. All else being equal, the magnitude of exchange or
flux is related directly to the surface areas (SA) of the
exchanging compartments and inversely to the distance (D) between them (i.e., SA/D).
B. SA is proportional to the square of body size, and mass
and volume are proportional to the cube of body size.
Thus to paraphrase Haldane (9), physiology is largely
the story of evolution’s struggle to maintain an appropriate SA/D in relation to volume or mass as organisms evolve changes in size. A small number of solutions* (which are not mutually exclusive) have
evolved repeatedly, including
i. change the shape of compartments when they vary
in size;
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Fig. 2. Similar phenomenological laws describe flux or exchange among
compartments within organisms or between organisms and their environment.
These (and their component variables) specify the options that evolution may
use* to regulate flux. At first glance, the 4 underlined equations, corresponding
to Ohm’s, Fick’s, Newton’s, and Darcy’s laws (top to bottom), seem strikingly
different, involving very different symbols, variables, and processes. the gray
vertical bars in the background emphasize that these laws are essentially the
same in form. Ohm’s: I, electrical current; R, electrical resistance; E, electrical
potential. Fick’s: M, mass flux; G, diffusive conductance; P, pressure of
diffusing species. Newton’s: Q, heat flux; C, thermal conductance; T, temperature. Darcy’s: M, mass flux; ␬, hydraulic conductance; P, pressure of flowing
medium. Subscripts 1 and 2 refer to two compartments between which
exchange occurs.
ii. conserve SA/D in relation to the mass or volume
of each compartment, but vary the number of
compartments (e.g., alveoli in lungs, villi in gut);
and
iii. embed highly conductive but highly regulatable
elements (e.g., channels, transporters, and pumps–
proteins) in a relatively poorly conductive matrix
(e.g., cell membrane or wall–lipid and/or carbohydrate), or vice versa (e.g., embed highly insulative
but regulatable elements such as hair, feathers,
scales in a relatively conductive matrix, such as
the vertebrate integument).
C. All else being equal, the magnitude of exchange or
flux among compartments is also related directly to the
difference or gradient among them (Fig. 2). This gradient can be manipulated to increase, decrease, or
maintain flux.
D. Because much (e.g., chemical diffusion, heat exchange
via conduction) but not all (e.g., electromagnetic radiation exchange) trans-surface exchange is rapid over
short distances but slow over long distances [10B], an
additional common solution* is to couple bulk flow or
analogous processes (e.g., action potentials) for exchange over long distances with trans-surface processes for exchange over short distances.
11. Exchanges via bulk flow and analogous processes (e.g.,
circulation, ventilation, axonal and dendritic neurotransmission) can be manipulated and exploited* according to
their underlying principles.
A. All else being equal, the magnitude of bulk flow or its
counterpart is related directly to the cross-sectional
area of the flow and the ease with which the flowing
substance (e.g., fluid or charge) moves, and inversely
to the length of the conduit.
B. As with trans-surface exchange, a small number of
solutions* (which are not mutually exclusive) have
evolved repeatedly, including
i. change the shape of conduits when they vary in
size. Such change can be both acute (via valves,
sphincters, and regulated channels) and chronic;
ii. vary the number and arrangement of conduits.
(That is, implement serial vs. parallel architecture,
manifolds, converging and diverging conduits as
necessary.); and
iii. embed highly conductive but highly regulatable
elements (e.g., aquaporins, insect tracheae) in a
relatively poorly conductive matrix.
C. All else being equal, the magnitude of bulk flow
among compartments is also related directly to the
pressure difference or gradient among them. This gradient can be manipulated to increase, decrease, or
maintain flux (e.g., ventilation, circulation).
D. Because bulk flow and its counterparts can be rapid over
long distances, an additional common solution* is to
couple bulk flow or analogous processes (e.g., action
potentials) for exchange over long distances with transsurface processes for exchange over short distances.
E. Unlike engineered bulk flow, much biological bulk
flow is through conduits whose compliance and elasticity are both high and dynamic. These properties,
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AIMS OF PHYSIOLOGY EDUCATION
together with [11A–C], enable organisms to generate
and regulate bulk flow dynamically.
12. Fluxes of each mass and energy species are as diverse as the
physicochemical differences among these species, often com-
7
partment specific, must vary dynamically in response to
changing supply and demand, and are often coupled with one
another. Physiological mechanisms that regulate these fluxes
are corresponding solutions to these challenges.
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Fig. 3. Two examples of coupled fluxes. In the first (top), heat, water, nutrient, and nitrogenous waste fluxes are coupled (15). In the second (bottom), 2 bulk flow steps,
2 diffusion steps, and chemical ATP synthesis are coupled (20). In principle, each example could be expanded (e.g., by incorporating CO2 flux and pH regulation), the
two examples could be combined, and indeed fluxes of all mass and energy species (Fig. 1) could be incorporated. All fluxes are linked to one another. Top: coupled
equations for heat and mass balance. The long center diagonal equation is the heat-balance equation. The top and bottom horizontal equations are the dry mass balance
and the water mass balance, respectively. Food ingested, which includes dry matter and water, is the left diagonal boxed equation. The masses involved in growth,
reproduction, or fat storage are diagonal boxed equations on the right side of the figure [from Porter (15); © 1989 by the University of Chicago. All rights reserved.].
Bottom: model of the respiratory system of mammals in the form of a cascade. The oxygen flow rate through each of the sequential steps is the product of a pressure
difference and a conductance. In a steady state, the flow rates through all steps must be equal. V, volume per unit time; P, pressure; I, inspired; E, expired; A, alveolar;
b, blood; a, arterial; v, venous; c, cell; G, conductance [Reprinted with permission from Taylor and Weibel (20).].
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AIMS OF PHYSIOLOGY EDUCATION
Fig. 4. Organisms, like almost everything complex, are a series of nested “bow
ties,” in each of which numerous, diverse, and unpredictable inputs are
integrated by a relatively small number of signaling-control-synthetic intermediaries to yield diverse and flexible outputs. The result is robustness to
environmental uncertainty but fragility when central processes are disrupted. In
A, the pathways of intermediary metabolism (middle top) are themselves a bow
tie with key intermediates at their core. (Figure adapted from Ref. 3).
computational capacity, convergence and divergence, and amplification, and have both spatial and
temporal aspects. The necessity to couple systems
through key intermediates (e.g., [12D]), however,
also confers fragility; and
iii. contribution of any component to fragility of the
entire system is related to its redundancy and
position in the network of interacting components.
E. In many environments mass and energy species required for life are far from abundant, the operation of
regulatory systems itself imposes additional requirements for mass-energy input-output, and these requirements are proportional to the difference between the
internal organismal environment and external environment. These and other considerations in essence pose
a risk-reward investment decision* for evolution in
every generation.
G. The ultimate indication of the efficacy of regulatory
systems is not their elegance, complexity, or uniqueness, but the success of the organism in which they
occur [5].
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A. The typical basis for these regulatory mechanisms is
conformational change in biological molecules, typically proteins.
i. Sensors are molecules or ensembles thereof that
undergo conformational change in response to
variation in the mass or energy species being
sensed, or its/their proxy, and emit (chemical/
electrical/mechanical) informative signals.
ii. Controllers are molecules or ensembles thereof
whose conformation or abundance is tantamount
to a comparison of actual mass-energy abundanceflux with desired* mass-energy abundance-flux,
and emit (chemical/electrical/mechanical) informative signals in response.
iii. Effectors are molecules or ensembles thereof that
undergo conformational change in response to informative signals, and thereby affect (perturb or
maintain) the physicochemical variables of mass
and energy flux.
iv. The foregoing three functions range from occurring in a single molecule or ensemble thereof to
occurring in numerous steps and compartments
and at time scales ranging from near-instantaneous
to the entire lifespan.
B. The processes of genomic diversification and the capacity to regulate or program gene expression dynamically have resulted in correspondingly diverse biological molecules and structures for accomplishing regulation, including
i. sensors that are responsive to one, some, or many
species of mass and/or energy;
ii. controllers that perform most arithmetic and logical functions;
iii. effectors that perturb or maintain one, some, or
many physicochemical variables of mass and energy flux;
iv. signaling that is informative to one, some, many,
or most kinds of sensors, controllers, and effectors;
and
v. variants that range from specific to general with
respect to space (i.e., compartment within the
organism) and time scale.
C. Despite this diversity (or perhaps because of common
evolutionary origin or as an inevitable design constraint of complex systems), a remarkably small suite
of signals accounts for a large proportion of informative signaling (e.g., phosphorylation changing protein
conformation, a small suite of second messengers, G
proteins, voltage gating of channels, a relatively small
suite of extracellular ligands and messengers) (Fig. 4).
D. Although some regulatory mechanisms are exclusively
molecular, many involve higher-order ensembles of
structural-functional elements. Common motifs are
i. massive parallelism and redundancy of simpler
elements, functions, or modules;
ii. emergent properties. That is, higher-order ensembles have functions and capacities not predictable
from their individual components in isolation. The
range in specificity, complexity, and dynamism
[12B] often arises from such ensemble properties.
These also include robustness to perturbation,
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In conclusion, again, this is a personal view of the essential
items that an undergraduate physiology course should communicate, and their exemplification through presentation of actual
physiological systems and mechanisms is the nuts and bolts of
physiology teaching. It may be that every physiology instructor
has a different set of key concepts, and justifiably so. But,
whatever the ideal set of key concepts, physiology instructors
must take care that the exemplification process does not overwhelm or obscure the key concepts themselves.
III. WHAT ARE THE AIMS OF PHYSIOLOGY EDUCATION?
WHAT ABOUT PHYSIOLOGY IS SO IMPORTANT THAT IT
SHOULD REMAIN A PROMINENT COMPONENT OF
UNDERGRADUATE TRAINING IN THE LIFE SCIENCES, IN
SCIENCE IN GENERAL, AND IN THE LIBERAL ARTS?
In the visible spectrum, it is impossible to tell where yellow
ends and orange begins or where orange ends and red begins.
These days, in the life sciences, it is impossible to tell where
biochemistry ends and physiology begins or where evolutionary biology ends and genetics begins. Several recent prominent
developments in the life sciences and medicine, including
systems biology (10), quantitative biology, and evolutionary
and ecological functional genomics (7), are specifically predicated on this realization. Above [13], I have suggested that
physiology is necessarily coupled to multiple other disciplines.
As with the visible spectrum, which grades into the ultraviolet
on one end and infrared on the other, the life sciences grade
into the physical sciences at one end and the social sciences,
humanities, and the professions (e.g., law, medicine, agriculture), at the other. Just as most economies, organizations,
people, computers, organismal components, and components
of physical systems are linked (1, 8), most of knowledge is
linked. What this means intellectually is that any discovery in
any discipline has the potential to inform any (if not every)
other discipline. What this means pragmatically is that, to be a
good physiologist (or, for that matter, any other kind of
-ologist), one must be aware of the entire knowledge environment [If the entirety of an organism’s genes is its genome and
the entirety of its proteins is the proteome, then the entire
knowledge environment is the sciome and its study “sciomics”
(6).]
Sciomics is daunting. In each new issue of Science or
Nature, potentially any page on any topic may contain the next
new breakthrough in one’s home discipline. But, while reading
these pages may not be particularly difficult, understanding
them (and their implications) and evaluating their potential
impact on ones’ own work can be extremely challenging.
Perhaps the key challenge is in understanding how and where
each new development fits in to one’s home discipline, i.e.,
context. For example, for many strict biochemists, luminescent
and fluorescent signaling to predators, prey, symbionts, and
conspecifics in marine ecosystems must have seemed like
trivial natural history; the key advance was in seeing the
implications of this natural history for biochemistry. Likewise,
for years many ecologists must have regarded the discovery of
diverse secondary compounds in plants and insects as trivial
chemical phenomenology; the key advance was realizing that
these underlie massively complex and important chemical
warfare in most terrestrial ecosystems. (Lest all biochemists
and all ecologists feel disparaged, the same could be said of
many scientists, even some physiologists.)
Perhaps the seminal importance of physiology is neither the
principles it articulates nor the mechanisms it discovers but the
context it provides for integrating diverse information, i.e., for
doing sciomics. Physiology teaches that all biological phenomena are connected. Again, as George Bartholomew has written,
“Every level of biological organization finds its mechanism at
lower levels of biological organization and its significance at
higher levels of biological organization” (2). Any complete
scientific explanation in physiology will therefore ultimately
involve every level of biology. Importantly, physiologists expect these connections to exist. A physiologist reading a
description of a novel channel in Science or Nature will
automatically ask of its significance for membrane conductance or organismal ionoregulation or wonder about its specific
gating mechanisms and ligands. For a physiologist, a description of a bizarre novel species, disease, or notably extreme
environment will automatically pose hypotheses of mechanism
and significance. Clearly, if there is any prescription for success in this new sciomic world, it is to survey the sciome
broadly for those chance discoveries that will inform one’s
own home discipline and one’s own research program. But if
“chance favors the prepared mind” [Pasteur (14)], physiology
deserves a prominent place in today’s undergraduate curriculum, because it is one of the few courses of instruction that
specifically prepares its students’ minds to make connections
among disciplines. In other words, physiology teaches one to
read Science and Nature intelligently. If science (or sciomics)
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13. The intellectual relationship of physiology to other disciplines is disciplinary coupling.
A. Understanding physiological unity and diversity involves understanding the role of evolution in creating,
maintaining, and/or constraining physiology. This in
turn involves understanding the genetic machinery
whose variation is necessary for evolution, necessitating a disciplinary coupling of physiology, evolutionary
biology, and genetics.
B. Understanding both organismal-environmental exchange and the environmental perturbation of physiological systems involves knowledge of the environment, necessitating a disciplinary coupling of physiology and ecology. For large and mobile organisms, in
which responses to the environment are often behavioral, a disciplinary coupling of physiology and behavioral biology is pertinent as well.
C. Mass and energy exchange, transformation, and utilization obey the laws of chemistry and physics. Any
fundamental understanding of these processes will
necessitate a disciplinary coupling of physiology,
physics, chemistry, and structural biology.
D. In essence, any physiological mechanism that includes
gene expression involves the control of development
by ecology (21), necessitating a disciplinary coupling
of physiology and developmental biology.
E. As Lee Hood has written (10), biology in a sense is a
specific case of a general problem of storage, analysis,
and dissemination of information, of which coordination, regulation, and integration of the components of
an organism is an even more specific case. Deep
understanding of physiology therefore necessitates a
disciplinary coupling with informatics.
9
A Personal View
10
AIMS OF PHYSIOLOGY EDUCATION
is “a way of knowing” (12), then physiology is a way (if not a
superior way) of knowing science or doing sciomics.
ACKNOWLEDGEMENTS
The author thanks Lorna P. Straus and the BioSci 20242 class of Spring
2004 for their comments on the manuscript. I am indebted to countless
educators, colleagues, and students, who have contributed to the views expressed here.
7.
8.
9.
10.
GRANTS
11.
12.
Preparation of the manuscript was supported by National Science Foundation Grant IBN03–16627.
13.
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15.
17.
18.
19.
20.
21.
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