Exam I (supplement 3)

Question 1

What are the most species rich environments?

Answer 1

• tropical forests
• coral reefs
• the ocean
• mediterranean type communities

Question 2

What is an endemic species?

Answer 2

species that is found in a particular location and nowhere else

Question 3

Variation in climate and environment

Answer 3

note: it is clear that local variation in climate, environment, topography and geological age are factors that affect patterns in species richness
- in terrestrial communities: species richness tends to increase due to decreasing elevation, increasing solar radiation, and increasing precipitation (hot, rainy, and lowland)
- these factors must act in combination for high rate of species

Question 4

Variation in topography, geological age, and habitat size

Answer 4

• species richness can be greater where complex topography and great geographical age provide more environmental variation, which allows genetic isolation, local adaptation, and specification to occur
• larger areas also can provide a greater range of habitats in which species can evolve and live

Question 5

Geographical barriers

Answer 5

fundamental niche + competition -> realized niche

-> niche portioning

Question 6

Why are there so many species in the tropics?

Answer 6

• number of species increases closer to the equator
• receive more solar energy over the course of a year than temperate regions, and many of them have abundant rainfall
• species of tropical communities have had longer periods of stability than species of temperate communities, which have had to disperse in response to periods of glaciation
• warm temperatures and high humidity in many tropical areas provide favorable conditions for the growth and survival of many species
• greater niche specialization

Question 7

How many species are on the planet? why is it important to know?

Answer 7

• 1.5 million have been described, estimated to be between 5-10 million though.
• in order to know the level of biodiversity we have and to determine what we have before we lose it

Question 8

Groups of species described and not described

Answer 8

described:
- vertebrates (birds and mammals)
- plants (temperate flowering plants

not described:

• viruses
• bacteria
• nematodes
• crustaceans
• protists
• algae
• mollusks
• fungi
• spiders
• insects