Study Guide – Chapter 4 - Biodiversity and Evolution
The American alligator is an important
in southern wetland ecosystems, and
has made a significant comeback since the 1960s.
It contributes significantly to the
Louisiana economy, and continues to provide many ecosystem services in Louisiana’s
coastal marshes and freshwater swamps.
is a renewable resource, and as the book says, includes not only the planet’s
species, but the linkages among those species, the ecosystems they live in, and the
ecosystem processes (energy flow and nutrient cycling) and services that keep these
is important, but
may be even more important; the
variability in the genetic composition of individuals within populations is the basis of evolution
and adaptation to changing environmental conditions.
is obvious as
you look around the world at the various biomes and aquatic life zones on the planet - all of
these ecosystems contain unique and potential important (to the ecosystem and to us, either
directly or indirectly) organisms that need to survive if the planet is to continue to function as
it has for thousands of years - remember stewardship?
As such, biodiversity is more than
an esoteric concept for ecologists - it is critical to how the Earth functions and adapts to
is also important, how all of the biotic and abiotic
components of an ecosystem interact with one another.
Maintaining all of these diversities is
a cornerstone of conservation; we have a responsibility to future generations to protect our
Earth’s biodiversity resulted from 3 billion+ years of
, the process whereby Earth’s
species emerge, change, and become extinct.
Charles Darwin and Russel Wallace
as the process whereby organisms become adapted to a
particular environment and thrive.
Small environmental changes probably do not alter
species too much, as the genetic diversity within populations allows them to persist.
However, as environments change rapidly, or new species evolve from genetic mutations,
some individuals will survive better and produce more offspring, hence future generations
will resemble the more “fit” individuals, and species, communities, and ecosystems change.
As you can see in Figure 4-3, we now classify organisms into 6 kingdoms, 2 prokaryotes and