The Science Book

A CENTURY OF PROGRESS 133

Nature’s unifying forces
Humboldt’s approach to nature
followed in the late 18th-century
Romantic tradition that reacted
to rationalism by insisting on the
value of senses, observation, and
experience in understanding
the world as a whole. Like his
contemporaries, the poets Johann
Wolfgang von Goethe and Friedrich
Schiller, Humboldt promoted the
idea of the unity (or Gestalt in
German) of nature—and of natural
philosophy and the humanities. His
studies ranged from anatomy and
astronomy to mineralogy and
botany, commerce, and linguistics,
and provided him with the breadth
of knowledge necessary for his
exploration of the natural world
beyond the confines of Europe.
As Humboldt explained, “The
sight of exotic plants, even of dried
specimens in a herbarium, fired my
imagination and I longed to see
the tropical vegetation in southern
countries with my own eyes.”
His five-year exploration of Latin
America with the French botanist
Aimé Bonpland was his most
important expedition. Setting out
in June 1799, he declared, “I shall
collect plants and fossils, and make
astronomical observations with the
best of instruments. Yet this is not
the main purpose of my journey. I
shall endeavor to discover how
nature’s forces act upon one another
and in what manner the geographic
environment exerts its influence on
animals and plants. In short, I must
find out about the harmony in
nature.” And he did just that.
Among many other projects,
Humboldt measured ocean water
temperature and suggested the use
of “isolines,” or isothermal lines, to
connect points of equal temperature

as a means of characterizing and

mapping the global environment,

especially the climate, and then

comparing the climatic conditions

in various countries.

Humboldt was also one of

the first scientists to study how

physical conditions—such as

climate, altitude, latitude, and

soils—affected the distribution of

life. With Bonpland’s assistance, he

mapped the changes in flora and

fauna between sea level and high

altitude in the Andes. In 1805,

the year after his return from the

Americas, he published a now-

celebrated work on the geography

of the area, summarizing the

interconnectedness of nature and

illustrating the altitudinal zones of

vegetation. Years later, in 1851, he

See also: Jean-Baptiste Lamarck 118 ■ Charles Darwin 142–49 ■ James Lovelock 315

Nature can be represented

as one great whole.

These interactions must include...

...biotic factors, such

as human activity and animal

and plant communities.

...abiotic factors, such

as climate, soils, and the

hydrological cycle.

Ecology is the study of all the interactions

between organisms and their environment that

determine their distribution and abundance.

showed the global application

of these zones by comparing the

Andean zones with those of the

European Alps, Pyrenees, Lapland,

Tenerife, and the Asian Himalayas.

Defining ecology

When Haeckel coined the word

“ecology,” he too was following in

the tradition of viewing a Gestalt

(unity) of the living and inanimate

world. An enthusiastic evolutionist,

he was inspired by Charles Darwin,

whose publication of On the Origin

of Species in 1859 banished the

notion of Earth as an immutable

world. Haeckel questioned the role

of natural selection, but believed

that the environment played an

important role in both evolution

and ecology. ❯❯