1.4: Classifying Types of Biodiversity
pg. 31
Species Diversity: the variety and abundance of species in a given
area.
Genetic Diversity: the variety of heritable characteristics (genes) in
a population of interbreeding individuals.
Ecosystem Diversity: the variety of ecosystems in the biosphere.
Genetic Diversity
Genes are the genetic material that controls the expression and
inheritance of traits. The variation among individuals in a
population is the result of the differences in their genes.
The genetic diversity within a population is known as the gene
pool (p + q = 1.00). The gene pool is the sum of all versions of all
genes within the population.
Genetic Diversity Provides Resistance to Disease
Genetic diversity is especially important to disease resistance.
Populations that lack genetic diversity are more susceptible to
disease than those that have a higher diversity. A disease can
eliminate an entire population of a species, and lead to extinction if
there is not enough diversity. Genetic diversity also allows a specie
and population to survive changes in the environment.
Genetic Diversity Supports Conservation Biology
Learning Check: questions 18 – 23, pg. 33
Ecosystem Diversity
Ecosystem diversity refers to the variety of ecosystems in the
biosphere. The ecosystem is made up of biotic (living) factors and
abiotic (non-living) factors. The Earth’s surface is highly varied
physically and chemically.
Ecosystem Services
Ecosystem services are the benefits experienced by organisms,
including humans, which are provided by sustainable ecosystems.
(Carbon sink holes, and soil fertility)
Ecosystem Function and Species Diversity
Resilience: the ability of an ecosystem to remain functional and
stable in the presence of disturbances to its parts.
An ecosystem with greater species diversity, provides important
ecosystem services more reliably.
Also with species diversity an ecosystem show more resilience,
ability to maintain an equilibrium or balance, in response to
significant outside disturbances.
Ecosystem Services and Human Actions
Humans sometime make changes to an ecosystem to enhance the
services of the ecosystem. These changes may lead negative
impacts on the natural ecosystem.
e.g.: Ontario – stocking lakes with smallmouth bass.
Biology Connections, pg 36
Section 1.4 Review: questions 1 – 11, pg. 37
Chapter 1: Review: questions 1 – 35, pg. 45 – 47
Chapter 1: Self Assessment: questions 1 – 23, pg. 48 – 49