We often need different scientific fields to work together to make sense of the world. Take photo- synthesis. Figuring out how plants convert light into energy requires quantum physics to understand
how light excites electrons in chloroplasts,
as well as cell biology and biochemistry to
explain how plants harness those electrons
to produce chemical energy.
For multidisciplinary approaches to work,
a common ground first needs to exist be-
tween scientific fields. However, finding
shared territory has not always been easy.
In the late 19th century, for example, bi-
ologists were investigating whether a “vital
force” was inherently necessary for life, and
physicists were just about to discover the
electron. At that time, it would have been an
enormous leap to suggest that energy from
electrons could be harvested by plants and
that this energy was part of the mysterious
force biologists were searching for.
Historian Peter Watson’s new book,
Convergence, chronicles a series of major scientific milestones spanning the past two
centuries, with the purpose of identifying
when overlaps between different research
fields began to occur.
One gets a sense that sciences meet almost serendipitously. In 1785, for example,
James Hutton suggested that the heat of
Earth was responsible for slowly turning
mud and sand into sedimentary rocks, a
theory that would become one of the fundamental principles of geology. A caveat
of Hutton’s hypothesis was that Earth was
millions, not thousands, of years old, as had
previously been assumed.
This revision to Earth’s age was of use
to Darwin, whose theory of evolution
would have been difficult to reconcile with
a shorter time frame. Indeed, it was later
found that more biologically complex fossil
specimens appear in younger rocks, a dis-
covery that lent support to both Hutton’s
and Darwin’s theories and gave way to the
field of paleobiology.
When disparate sciences move closer
together, the traditional borders that once
kept them apart begin to weaken. This
opens the door for imagining new questions
that can only be addressed by drawing on
the knowledge and techniques found in two
Watson sheds light on what can be gained
when different research areas achieve such
convergence. One of the benefits that he
identifies is the ability to break disciplines
up into smaller pieces. For instance, our understanding of ecology is enriched by knowing the role that is played by genetics and is
enhanced further still when we understand
that genetics can be broken down into biochemistry and physics.
Reductionism is only one side of the coin.
Just as much can be gained by investigating how systems-level sciences emerge out
of more fundamental fields. It’s useful, for
example, to describe a gene by the physical forces that hold it together, but it’s also
worth asking what evolutionary pressures
are responsible for causing that gene to exist
in the first place.
Watson makes clear that convergence be-
tween different scientific branches is ongoing
and that we are still struggling to understand
how some phenomena fit together. We’re still
unsure, for example, how consciousness can
be produced from neuronal circuits or why
subatomic particles are allowed to be in two
places at once, whereas the macroscopic
objects they make up are not.
Will we ever achieve complete convergence across every scientific field, thus producing a “master set of rules from which
all truth would flow” (1)? Although we may
not get that far, Watson is impressed by the
progress made in the past 200 years and
seems convinced that we are at least on the
While Watson examines an impressive
array of connections between disciplines,
what’s missing is a rigorous evaluation
of the strength of the associations being made. This is especially critical when
exploring new frontiers of convergence,
where the strong desire for a unified theory could encourage connections that are
at best superficial. For instance, is the way
that organisms code and express genes
truly convergent with computer processing
and information theory, or is this merely
Although the links between fields may
seem fragile in some places, Watson’s overall argument remains convincing. Whether
you identify as a biologist, an astrophysicist, or a mathematician, one thing’s for
certain: We’re all ultimately working with
the same fabric. j
1. R.B.Laughlin, A Different Universe: Reinventing Physics
from the Bottom Down (Basic Books, 2006).
HISTORY OF SCIENCE
A provocative history
probes the connections
that are helping to unify
The reviewer is in the Center for Genomics and Systems
Biology, New York University, New York, N Y 10003, USA.
By Joseph Swift
Convergence in the fields of ethology and psychology led to the theory of attachment, argues Watson.
The theory places the mother-infant bond in biological and evolutionary context.
The Idea at the Heart
Simon and Schuster, 2017.