33. Biodiversity And Extinctions

Question 1

What does extinction mean?

Answer 1

The failure of a population or species to maintain itself through reproduction

Question 2

What is the historic rate of species lost compared to the current rate?

Answer 2

Historically: 9% per million years Currently: 9% per 10 years

Question 3

What are the three major causes of animal extinction?

Answer 3

Species introductions (species that are meant to be there), hunting and habitat destructions

Question 4

What do animals need to do for survival?

Answer 4

A habitat that provides the survival and reproductive requirements of individuals in the populations

Question 5

What are the four sources of that contribute to extinction?

Answer 5

Genetic factors (genetic drift, bottlenecks, founder effects and inbreeding) Demographic factors - sex ratio, reproductive output and age of first reproduction Environmental factors - weather, food supply, competitors Metapopulation dynamics - distribution and mobility of animals

Question 6

What is a population viability analysis?

Answer 6

Incorporates the probabilities of all known risks to population persistence through time. If animal is doing well vs badly

Question 7

What are three key ways to prevent extinction?

Answer 7

1. Supplement natural populations or establish new populations 2. Preservation of habitat 3. Protection from invasive species

Question 8

What are the three levels of biodiversity

Answer 8

Genetic diversity, Species diversity Ecosystem diversity

Question 9

Why do we need to care about biodiversity loss? Two points

Answer 9

Moral arguments and benefits of species and genetic diversity

Question 10

What are the benefits of species and genetic diversity? Two points

Answer 10

The undiscovered beneficial organisms to help with medicines (economical) Genetic variation to for horticulture so they dont become resistant

Question 11

What are the five major threats to biodiversity? What is the ultimate cause?

Answer 11

Habitat destruction Introduced species Overexploitation Disruption of ecosystem dynamics Global change Ultimately caused by overpopulation

Question 12

How does habitat destruction occur to reduce biodiversity?

Answer 12

Human alteration - the greatest cause

Question 13

What are introduce species?

Answer 13

Species that expand from their native location to new places

Question 14

What is overexplotiation?

Answer 14

Human harvesting wild plants or animals that are to fast for the species to reproduce

Question 15

What is the small population approach?

Answer 15

Study the processes that can cause small populations to become extinct. Extinction vortex from inbreeding and genetic drift