Ecosystem
Year of Discovery: 1935
What Is It? The plants, animals, and environment in a given place are all interdependent.
Who Discovered It? Arthur Tansley
Why Is This One of the 100 Greatest?
Many scientists over the centuries had studied the relationship of various species to
their climate and environment. They studied elements of ecology. However, it wasn’t until
1935 that Arthur Tansley realized that all species in a given environment were interconnected. Grasses affected top carnivores and the bugs that decomposed dead animals, and
fallen trees affected grasses and bushes.
Tansley discovered that every organism is part of a closed, interdependent system—an
ecosystem. This discovery was an important development in our understanding of biology
and launched the modern environmental movement and the science of ecology.
How Was It Discovered?
Arthur Tansley was the person who saw the big picture and discovered that all elements of a local ecological system were dependent upon each other, like individual threads
in a tightly spun web. But he was not the first person to study ecology.
Aristotle and his student, Theophrastus, studied the relationships between animals and
their environment in the fourth century B.C. In 1805, German scientist Alexander von
Humbolt published his studies of the relationship between plant species and climate. He
was the first to describe vegetation zones.
Alfred Wallace, a competitor of Darwin’s, was the first to propose (in 1870) a “geography” of animal species, relating animals to their climate and geography. In the early nineteenth century, French scientist Antoine Lavoisier discovered the nitrogen cycle. This cycle
linked plants, animals, water, and atmosphere into a single interdependent cycle by tracing
how nitrogen cycles through the environment. What science needed was for someone to
recognize that all of these individual pieces fit together like pieces in a jigsaw puzzle.
Arthur Tansley was born into a wealthy family in London in 1871. He earned a degree
in botany and lectured throughout his working career at University College in London and
then at Cambridge. Tansley was active in promoting English plant ecology and helped
found the British Ecological Society.
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