Tansley introduced the concept
of the ecosystem—the interactive
relationship between living
organisms and the environment
in which they live. Later ecologists
developed mathematical models to
forecast population dynamics within
ecosystems. Evolutionary theories
also advanced with the discovery
of the structure of DNA, and the
evolutionary “vehicle” provided
by mutation as DNA is replicated.New frontiers
Improved technology opened up
new possibilities for ecology. An
electron microscope can now
make images to half the width of a
hydrogen atom, and computer
programs can analyze the sounds
made by bats and whales, which are
higher or lower than can be heard
by the human ear. Camera traps and
infrared detectors photograph and
film nocturnal creatures, and tiny
satellite devices fitted to birds can
track their movements.
In the laboratory, analysis of
the DNA of feces, fur, or feathers
indicates which species an animal
belongs to, and throws light on
the relationship between different
organisms. It is now easier than
ever for ecologists to collect data,
helped by a growing army of
citizen scientists.New concerns
Early ecology was driven by a
desire for knowledge. Later, it was
used to find better ways to exploit
the natural world for human needs.
As time went on, the consequences
of this exploitation became
increasingly evident. Deforestation
was highlighted as a problem as
early as the 18th century, and the
problems of air and water pollution
became obvious in industrialized
nations in the 19th century. In 1962,
Rachel Carson’s book Silent Spring
alerted the world to the dangers of
pesticides, and six years later Gene
Likens demonstrated the link
between power station emissions,
acid rain, and fish deaths.
In 1985, a team of Antarctic
scientists discovered the dramatic
depletion of atmospheric ozone
over Antarctica. The link between
greenhouse gases and a warming
of Earth’s lower atmosphere had
been made as early as 1947 by
G. Evelyn Hutchinson, but it was
decades before there was a scientific
consensus on the man-made causes
of climate change.The future
Modern ecology has come a long
way since the science was first
recognized. It now draws on many
disciplines. In addition to zoology,botany, and their microdisciplines,
it relies on geology, geomorphology,
climatology, chemistry, physics,
genetics, sociology, and more.
Ecology influences local and
national government decisions
about urbanization, transportation,
industry, and economic growth.
The challenges posed by climate
change, rising sea levels, habitat
destruction, the extinction of
species, plastic and other forms of
pollution, and a looming water crisis
pose serious threats to human
civilization. They demand radical
policy responses based on sound
science. Ecology will provide the
answers. It is up to governments
to apply them. ■INTRODUCTION
Even in the vast and
mysterious reaches of the sea
we are brought back to the
fundamental truth that
nothing lives to itself.
Rachel Carson15
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