132
EVERY DISTINCT PART
OF NATURE’S WORKS
IS NECESSARY FOR THE
SUPPORT OF THE REST
THE FOOD CHAIN
IN CONTEXT
KEY FIGURE
Richard Bradley (16 8 8 –1732)BEFORE
9th century Arab scholar
Al-Jahiz describes a three-
level food chain of plant matter,
rats, snakes, and birds.1717 Dutch scientist Antonie
van Leeuwenhoek observes
how haddock eat shrimp and
cod eat haddock.AFTER
1749 Swedish taxonomist Carl
Linnaeus introduces the idea
of competition.1768 John Bruckner, a Dutch
naturalist, introduces the idea
of food webs.1859 Charles Darwin writes
about food webs in On the
Origin of Species.1927 British zoologist Charles
Elton’s Animal Ecology outlines
principles of animal behavior,
including food chains.Apex predatorLarger predator
(tertiary consumer)Carnivore
(secondary consumer)Herbivore
(primary consumer)The food chain
A
ll animals must eat other
living things in order to
receive the nutrients they
need to grow and function. A food
chain shows the feeding hierarchy
of different animals in a habitat.
For example, the chain would show
that foxes eat rabbits but rabbits
never eat foxes. Although there
were earlier notions of a hierarchy
of animals linked to each other in
a food chain, British naturalist
Richard Bradley brought more
detail to this idea in his book New
Improvements in Planting and
Gardening (1718). He noted that
each plant had its own particular
set of insects that lived off it and
proposed that the insects in turn
received the attentions of other
organisms of “lesser rank” that fed
on them. In this way, he believed
that all animals relied upon each
other in a self-perpetuating chain.Producers and consumers
The modern concept of a food chain
explains that some organisms
produce their own food. These are
known as producers, or autotrophs.
Plants and most algae fall into this
category, normally using the energy
of sunlight to convert water and
carbon dioxide into glucose, at theProducer (autotroph)
US_132-133_Food_Chain.indd 132 12/11/18 6:24 PM