1. Introduction to Biodiversity
Biology/Env S 204
Spring 2009

2. The variety of life
is biological diversity.

3. Use of the term
“biological diversity”
in its current sense began
in 1980.

4. Biodiversity = biological diversity
Coined in 1985 for a conference, the
proceedings of which were published
as the book “Biodiversity”edited
by E. O. Wilson.

5. What does it mean? The variability among living organisms from
all sources including terrestrial and aquatic
systems and the ecological complexes of
which they are a part; diversity within
species, among species, and of ecosystems;
interactions at all levels among organisms.

6. From Frankel et al., 1995, The conservation of plant biodiversity.

7. Fundamental levels of organization
Genetic
Organismal
Ecological

8. Ecological Diversity Communities of species, their interactions
Communities + resources (energy, nutrients, etc.) = ecosystem
Measured primarily in terms of vegetation but relative abundance of species also important
No unique definition and classification at the global level

9. Organismal Diversity Individuals, species
Mostly measured by numbers of species
Estimated 1.7 million species described to date
Estimated total number ranges from 2 to 50 million (up to 100 million) species
Mostly microorganisms and insects

10. Genetic diversity
Heritable variation within and between populations of organisms
Encoded in the sequence of 4 base-pairs
that make up DNA
Arises by mutations in genes
and chromosomes
Very small fraction of genetic
diversity is outwardly expressed

11. Why care about what we can’t see?
Genetic variation enables evolutionary
change and artificial selection
Estimated 109 different genes across
the Earth’s biota
Represents a largely untapped genetic
library