Lecture 32: Conservation Biology

Question 1

What is the back ground rate of extinction?

Answer 1

Extinctions that occur periodically:

• 10% of species are lost every 1 million years
• 30% every 10 million years
• 65% every 100 million years

Question 2

What are the big five mass extinctions?

Answer 2

444: end of ordovician
360: late devonian
280: end permian
200: end triassic
65: end cretaceous

Question 3

Explain end ordovician

Answer 3

• glacial and interglacial periods created large sea-level swings
• tectonic uplift of mountains created weathering, CO2 sequestration
• changes in climate and ocean chemistry
• 86% of species lost

Question 4

Explain late devonian

Answer 4

• rapid growth of land plants helped cool down the globe
• 75% of species lost

Question 5

Explain end permian

Answer 5

• intense volcanic activity that elevated CO2 levels and global warming
• ocean acidification and acid rain
• 96% of species lost

Question 6

Explain end triassic

Answer 6

• underwater volcanic activity caused global warming and affected the chemical composition of oceans
• 80% of species lost

Question 7

Explain end cretaceous

Answer 7

• asteroid impact that cause global cataclysm and rapid cooling
• 76% of species lost

Question 8

Define habitat degradation

Answer 8

Changes that reduce the quality of habitat for many species

Question 9

Pollution: define bioaccumulation

Answer 9

an increase in the concentration of a chemical in an organism over time because the chemical is not metabolized or excreted

Question 10

Pollution: biomagnification

Answer 10

increasing tissue concentration of chemicals in higher trophic levels due to consumption

Question 11

What are some approaches to conservation?

Answer 11

• genetic approaches
• demographic models: population viability analysis is used to estimate the likelihood that a population will persist under different management scenarios
• ex situ conservation

Question 12

What criteria can we use to rank species to protect?

Answer 12

Distinctiveness, vulnerability, and utility

Question 13

What are the 2 types of surrogate species?

Answer 13

1. flagship species: species that capture public attention and important for ecotourism
   2: umbrella: protecting a species’ habitat will serve to protect habitat requirements for many other species