Perspective

Systematics and the future of biology
Edward O. Wilson*

Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138-2902

Biology is a science of three dimensions. The first is the studyof each species across all levels of biological organization,
molecule to cell to organism to population to ecosystem. The
second dimension is the diversity of all species in the biosphere.
The third dimension is the history of each species in turn,
comprising both its genetic evolution and the environmental
change that drove the evolution. Biology, by growing in all three
dimensions, is progressing toward unification and will continue
to do so. A large part of the future of biology depends on
interdisciplinary studies that allow easy travel across the three
dimensions.

Molecular and cellular biology, the subdisciplines of maximum
support and activity today, occupy the two lowest levels of
biological organization. They are focused on the first dimension
in a small set of model species, selected primarily for their ease
of culturing and the special traits that make them amenable for
different kinds of analysis. The triumph of molecular and cellular
biology has been the documentation of one of the two overar-
ching principles of biology: that all living phenomena are obe-
dient to the laws of physics and chemistry. The other overarching
principle of biology is that all living phenomena originated and
evolved by natural selection. That, in turn, has been the triumph
of organismic and evolutionary biology.

Viewed in the framework of the history of biology, the
subdisciplines of molecular and cellular biology are in the natural
history period of their development. This perhaps surprising
characterization can be clarified with the following metaphor.
The cell is a system consisting of a very large number of
interacting elements and processes. It can be compared to a
conventional ecosystem, such as a lake or forest, in this sense:
Researchers are discovering the anatomy and functions of the
vast array of molecules, the equivalent of the species of plants
and animals in ecosystems, that compose the cell. These scien-
tists are the Humboldts, the Darwins, the Mayrs, and other
explorer-naturalists in a new age, and of a new kind. Mercifully
free of mosquito bites and blistered feet, they press forward into
the unmapped regions at the lowest levels of biological organi-
zation. They are not in the business of creating fundamental
principles, which they take mostly from physics and chemistry.
Their spectacular success has come instead from technology
invented and applied with creative genius. They render visible,
by crystallography, immunology, genic substitution, and other
methods, the anatomy and functions of the ultramicroscopic
inhabitants of the cell, which are otherwise entirely beyond the
range of the unaided human senses. They aim and can be
expected in time to join with researchers in other subdisciplines
of biology to develop the fundamental principles of biological
organization.

There remains the rest of biology, the vast and mostly unex-
plored upper reaches of the first dimension (levels of organiza-
tion), and the little known second dimension (diversity) and third
dimension (evolution). These domains do not belong to the past
of biology, nor are they antiquated and declining in any manner
or to any degree whatsoever, as is sometimes misperceived. They
are, in large part, the future of biology. Probably �10% of
species on the planet have been discovered, and of these only a

tiny fraction—�1%— have been addressed with more than a
cursory anatomical description.

Keep in mind that each species is unique in its genotype,
proteome, behavior, history, and environmental relationship to
other species. Until we learn more about the immense array of
Earth’s little known and entirely unknown species, how they
came into being, and what they are doing in the biosphere, the
development of the rest of biology, including molecular and
cellular biology, will be vastly incomplete. A further conse-
quence of the imbalance is that the relation of humanity to the
rest of the biosphere will stay largely uncharted territory. And
the means to save and manage the living environment for the
long term will remain very much a guessing game.

The proportionate shortfall of the disciplines can be expressed
in practical terms as follows. A large part of the success of
molecular and cellular biology is due to their relevance to
medicine. In public perception and support, they are virtually
married to medicine. Hence, molecular and cellular biology are
rich not so much because they have been successful; rather, they
are successful because they have been rich. What needs to be
appreciated for the future of organismic and evolutionary biol-
ogy in practical terms is that where molecular and cellular
biology are vital to personal health, organismic and evolutionary
biology are vital to environmental health, and thence also to
personal health.

The exploration of life on this little known planet needs to be
made the equivalent of the Human Genome Project. It should be
an all-out effort that sets the global biodiversity census as a goal
with a timetable and not just a result eventually to be reached.
In fact, the technology now exists to speed exploratory and
monographic systematics by at least an order of magnitude. This
technology includes high-resolution digital photography with
computer-aided automontaged depth of focus for even the
smallest and hence most highly magnified specimens. As a
practicing systematist, I am certain that the first order of business
must be to thoroughly photograph representatives of all species
for which either type specimens or indisputably authenticated
substitutes exist. The images can then be published on the
Internet for immediate access on command, available to anyone,
at any time, anywhere in the world.

Such virtual type collections can in most cases remove most of
the time-consuming necessity of visiting museums or securing
loans of often fragile specimens. Combined with online repro-
ductions of the original published descriptions and earlier mono-
graphs, they will accelerate the identification of vast numbers of
specimens now backed up in unprocessed collections around the
world. They will also allow the rapid preparation of revisionary
monographs, local biodiversity analyses, and the publication of
made-to-order field guides.

This paper results from the Arthur M. Sackler Colloquium of the National Academy of
Sciences, ‘‘Systematics and the Origin of Species: On Ernst Mayr’s 100th Anniversary,’’ held
December 16 –18, 2004, at the Arnold and Mabel Beckman Center of the National Acad-
emies of Science and Engineering in Irvine, CA.

*E-mail: ewilson@oeb.harvard.edu.

© 2005 by The National Academy of Sciences of the USA

6520 – 6521 � PNAS � May 3, 2005 � vol. 102 � suppl. 1 www.pnas.org�cgi�doi�10.1073�pnas.0501936102

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Systematics is now in the early stages of a technology-driven
revolution. A conference of biodiversity and informatics leaders
held at Harvard University in 2001 agreed that by using new
methods already available and including genomics, systematists
have the capacity to complete or nearly complete a global
biodiversity sur vey within a single human generation—25
years—at about the cost of the Human Genome Project. To give
a better feel for the magnitude of this biological moon shot,
consider that whereas very roughly 10% of Earth’s species (out
of, say, 15–20 million extant) have been discovered and named
in the past 250 years since Linnaeus inaugurated the hierarchical
and binomial system of classification, now it seems possible that
the remaining 90% can be so covered in 1�10th of that time.

If such a goal seems out of reach, consider that perhaps 1
million species of all kinds, mostly eukaryotes, have type spec-
imens in good enough condition for electronic republication.
The New York Botanical Garden has already processed and put
online the types of 90,000 plant species, and Harvard’s Museum
of Comparative Zoology is well on its way to processing �28,000
insect species. Thus, even in its earliest stages, at only two
institutions, the republication program has already reached the
hypothetical 10% level.

A new global systematics initiative is under way on three
fronts. The first is the all-species program, which aims to
measure the full breadth of biodiversity in all of the three
recognized domains, the Bacteria, Archaea, and Eucarya, by
using new and future technology. The next is the Encyclopedia
of Life, expanding the all-species program by providing an
indefinitely expansible page for each species and containing
information either directly available or by linkage to other
databases. The final and rapidly growing body of knowledge is
the Tree of Life, the reconstructed phylogeny of life forms in
ever finer detail, with particular reliance on genomics.

The upper levels of biological organization, from organism to
ecosystem, the mapping and analysis of biodiversity, and the
development of the Tree of Life all of the way from genes to
species will eventually amount to most of biology. These pro-
portionately still-neglected domains, therefore, offer intellectual
stock of substantial growth potential to universities and other
research-oriented organizations that invest in them now. It is still
relatively easy to provide leadership at the cutting edge of
biology extended beyond the molecular and cellular levels of a
few species. The cost would be low, and the returns to scale
incalculably great.

Wilson PNAS � May 3, 2005 � vol. 102 � suppl. 1 � 6521

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