The Ecology Book

186

A

metapopulation is a

combination of separate,

local populations of the

same species. The term was coined

by American ecologist Richard

Levins in 1969 to describe how

insect pest populations rise and fall

on farm fields. Since then, its use

has expanded to cover any species

broken up into local populations in

fragmented habitats, both on land

and in the oceans.

A particular species of bird, for

instance, may be found in separate

populations in a lowland forest, in

mountain woodlands, and various

other places. The species is like a

family whose members have moved

to different cities yet are still

related. The combined effect of

many populations may boost the

long-term survival of the species.

Apart but together

A crucial aspect of metapopulation

theory is the level of interaction

between the separate local

populations. If the level is high,

it is not considered to be a

metapopulation—all the local

groups are part of one big

population. In a metapopulation

IN CONTEXT

KEY FIGURE

Ilkka Hanski (1953–2016)

BEFORE

1931 In the US, geneticist

Sewall Wright explores the

influence of genetic factors

on species populations.

1933 In Australia, ecologist

Alexander Nicholson and

physicist Victor Bailey develop

their model of population

dynamics to describe the

host–parasite relationship.

1954 In The Distribution and

Abundance of Animals,

Australian ecologists Herbert

Andrewartha and Charles

Birch challenge the idea that

species populations are

controlled by density alone.

AFTER

2007 American ecologist

James Petranka links

metapopulation theory to

the metamorphosis stages

of amphibians.

Extinction and colonization are dynamic processes.

A species colonizes

an empty habitat patch.

A local extinction does not signal

the extinction of the species.

A species becomes

extinct in one

habitat patch.

A POPULATION

OF POPULATIONS

METAPOPULATIONS

US_186-187_Meta_populations.indd 186 12/11/18 6:25 PM