The Ecology Book

O

ur understanding of the

variety, behavior, and

interraction of organisms

has advanced considerably since

Aristotle discovered that bee

colonies have a queen and workers.

Huge advances in technology,

field observations, and laboratory

experiments have increased our

knowledge, and the modern study

of animal behavior—ethology—

continues to throw up surprises.

Life under the microscope

Until the microscope was invented,

no one knew that bacteria even

existed, let alone what they did.

Bacteria were first observed by

Dutch microscopist Antonie van

Leeuwenhoek in 1676, using

an instrument he had built himself.

He called these tiny organisms

“animalcules,” but little was known

about them for many years. In

the 1860s, French chemist Louis

Pasteur and German microbiologist

Robert Koch developed the germ

theory of disease, highlighting the

harmful role played by bacteria.

Subsequent research has also

highlighted their positive roles:

facilitating digestion; inhibiting

the growth of other, pathogenetic

bacteria; “fixing” or converting

nitrogen into molecules that aid

plant growth; and breaking down

dead organic material, which

releases nutrients for the food web.

Another discovery made

possible by microscopy was of the

mutualistic relationship between

fungi and trees, published by

German plant pathologist Albert

Frank in 1885. Studying what he

first assumed was a pathological

infection, Frank discovered that

trees with the fungi attached

to their roots were healthier than

those without. The fine filaments,

or hyphae, of the fungi make the

roots more efficient at obtaining

nitrate and phosphate nutrients

from the soil. In return, the fungi

get sugar and carbon from the tree.

Connected lives

No organism lives in isolation from

the rest of its ecosystem. The

behavioral interactions between

them are complex and much is still

being discovered about them. One

of the greatest contributions in this

field was made by British zoologist

Charles Elton, whose 1927 classic

Animal Ecology established many

important principles of animal

behavior, including food webs and

food chains, prey size, and the

concept of ecological niches.

INTRODUCTION

1590

Dutch lens-makers Hans

and Zacharias Janssen

invent the compound

microscope.

1866

Louis Pasteur reveals

that wine’s fermentation

process is caused by germs;

his discovery sparks the

development of germ theory.

1676

Antonie van

Leeuwenhoek

identifies “animalcules,”

opening up the field

of microbiology.

100

1927

Charles Elton publishes

Animal Ecology, which

sets out many of the

fundamental principles

of animal behavior.

1885

Albert Frank coins the

term “mycorrhizae,” in

reference to the symbiotic

relationship between

fungi and tree roots.

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