Chapter 2

Question 1

Levels of biodiversity

Answer 1

• Species diversity: all species on earth
• Genetic diversity: genetic variation within species among both geographically separate populations and among individuals within single populations
• Ecosystem diversity:different biological communities and their associations with the chemial and physical environment

Question 2

Definitions of a species

Answer 2

morphological, biological, evolutionary

Question 3

Pros and cons of Morphological species definition

Answer 3

Pro: easy, visual, quick
Con: different morphs of same specie

Question 4

Pros and cons of biological species definition

Answer 4

Pro: reproductive behavior is more unique from species to species so it is more accurate than morphological
Cons: interbreed/hybridize

Question 5

pros and cons of evolutionary species definition

Answer 5

Pro: You can definitely tell if they are different species
Con: Requires access to expensive lab equipment, time consuming, can’t do it in the field

Question 6

3 diversity measurements

Answer 6

alpha, gamma, beta

Question 7

Alpha diversity

Answer 7

of species in a given community

Question 8

Gamma diversity

Answer 8

species at larger geographic scale that include a number of ecosystems
- mountains, continent

Question 9

Beta diversity

Answer 9

rate of change of species composition as one moves across a large region
- Calculation: gamma/alpha

Question 10

Why is genetic diversity important?

Answer 10

• Necessary for any species to maintain reproductive viability, resist disease, and ability to adapt in changing environment
• genetically diverse species is more likely to adapt and survive

Question 11

Gene pool

Answer 11

total array of genes and alleles in a population

Question 12

What is the main way to distinguish species?

Answer 12

genetic code

Question 13

how many species exist? what species dominate this number?

Answer 13

~2 million species described (most are insects)

Question 14

How does species richness differ from species diversity? What are the methods for quantifying each?

Answer 14

Diversity: evenness in number of individuals per species
- Shannon Diversity Index
Richness: number of species in an area
- Count species

Question 15

What is the difference between an ecosystem and the biological community?

Answer 15

Ecosystem: biota along with the physical and chemical elements
- Biotic and abiotic
Biological Community: just the living organisms within an ecosystem

Question 16

What is an ecosystem engineer?

Answer 16

Species that extremely modify the physical environment through their activities
- Make completely different ecosystem
- Sometimes set back succession

Question 17

What is succession?

Answer 17

Progression on evolution starting with pioneer species (the ones that are the first to arise and pave the way for the following species) and the small plants such as grasses and perennials (intermediate species) and then finally the climax community