162
T
he distribution, or range, of
biological communities and
species varies according to
many factors—including latitude,
climate, elevation, habitat, isolation,
and the species’ characteristics.
The study of species distribution is
called biogeography. Biogeography
is also concerned with how and
why the patterns of distribution
change over time.
Early zoologists and botanists
such as Carl Linnaeus were well
aware of geographical variations inspecies’ distributions, but the first
to make detailed studies of this
aspect of zoology was the Prussian
polymath Alexander von Humboldt,
who traveled to Latin America with
French botanist Aime Bonpland in- Their five-year expedition
laid the basis of plant geography.
Humboldt believed observation in
situ to be paramount, and used
sophisticated instruments to make
meticulous records of both plant
and animal species, noting all the
factors that could influence the
IN CONTEXT
KEY FIGURE
Alexander von Humboldt
(176 9–1859)BEFORE
1750 Carl Linnaeus explains
that the distribution of plants
is determined by climate.AFTER
1831–36 Charles Darwin
makes various observations
on the voyage of HMS Beagle,
confirming that many animals
living in one area are not found
in similar habitats elsewhere.1874 British zoologist Philip
Sclater produces a description
of the zoogeography (the
geographical distribution of
animals) of the world’s birds.1876 Alfred Russel Wallace
publishes his two-volume book
The Geographical Distribution
of Animals, which becomes
the definitive biogeography
text for the next 80 years.THE PHILOSOPHICAL STUDY
OF NATURE CONNECTS THE
PRESENT WITH THE PAST
THE DISTRIBUTION OF SPECIES
OVER SPACE AND TIME
Plants and animals move
over time as Earth and its
habitats change.Species are
distributed
throughout the world.Scientists study
where and how species
live now but also where
they were before, and
what has changed.The philosophical
study of nature
connects the
present to the past.US_162-163_Distribution_of_species_in_time_and_space.indd 162 12/11/18 6:25 PM