Lecture 24: Biodiversity & Global Ecology: Biodiversity and humans

Question 1

To understand modern patterns of biodiversity decline, we must ______________________________________________

Answer 1

understand historical patterns of extinction

Question 2

The historical pattern of extinction is one of a relatively ___________________________ punctuated by _______________________.

Answer 2

• low level of background extinction
• mass extinction events

Question 3

There have been ______________________________________ in the history of life on earth.

Answer 3

five documented mass extinctions

Question 4

define mass extinction

Answer 4

The extinction of 75% or more of existing species over a period of 2 million years or less

Question 5

_____________________________________, but, _____________ evolve, and __________________________ are established.

Answer 5

• Existing ecological systems collapse
• new species
• new ecological systems

Question 6

Nevertheless, __________________________________________ than at any other period in history

Answer 6

more species are coexisting on earth today

Question 7

History of biodiversity is one of __________________. But, _______________________________________, because the ______________________________________________________.

Answer 7

• collapse and recovery
• few individual species make it through a biodiversity collapse
• ecological systems they depend on also collapse

Question 8

The ______________________________________, the _______________________________________________ is likely

Answer 8

• larger the extent of the extinction
• more the collapse of ecological systems

Question 9

What happened to mammal biodiversity after the arrival of humans?

Answer 9

• Lower species richness of mammals in the presence of humans.
• Stronger divergence at smaller scales = more local extinctions?

Question 10

____________ have been established to _____________________.

Answer 10

• New efforts
• track extinction

Question 11

categories for how close species are to extinction defined by International Union for Conservation of Nature

Answer 11

1. extinct
2. extinct in the wild
3. threatened
4. near-threatened
5. least concern

Question 12

categories for how close species are to extinction - extinct

Answer 12

known to be in the wild in the year 1500 (recent recorded human history) but no individuals are known to be alive today

Question 13

categories for how close species are to extinction - extinct in the wild

Answer 13

Only known individuals are in captivity

Question 14

categories for how close species are to extinction - threatened

Answer 14

Populations at high risk of extinction

Question 15

categories for how close species are to extinction - near-threatened

Answer 15

Species likely to become threatened soon

Question 16

categories for how close species are to extinction - least concern

Answer 16

Currently show no sign of population decline.

Question 17

We are now monitoring extinction status in real-time. Some groups are particularly well known and therefore ______________________.

Answer 17

good for monitoring

Question 18

what is found when monitoring non-extinction categories

Answer 18

• Threatened status differs substantially among groups.
• High proportion in some threatened status across groups
• Status of fish is particularly concerning for humans in near-term

Question 19

experimental reduction in plant species richness results in what?

Answer 19

less plant biomass in the ecological system

Question 20

what happens to primary production as biodiversity declines?

Answer 20

Primary production is lost as biodiversity declines

Question 21

Biodiversity loss means ____________________

Answer 21

less genetic diversity

Question 22

_________ genetic diversity means _________________ for long-term survival.

Answer 22

• Lower
• less variation

Question 23

Humans rely primarily on _________________________________ (cows, pigs, sheep, goats, buffalo, horses, and donkeys) for food and labor, and _______________ (chickens, turkeys, ducks, and geese)

Answer 23

• seven species of mammals
• four species of birds

Question 24

Worldwide, original wild species are extinct or unknown, and many domesticated breeds are now extinct. — _________________________________________________________

Answer 24

We rely on a small number of genetically inbred breeds for much of our food.

Question 25

Large numbers of ____________ of food species used to be maintained, to _______________________________, keeping genetic diversity high.

Answer 25

• local varieties
• tolerate local conditions

Question 26

____________________ has favored only a few varieties, resulting in huge ________________________________

Answer 26

• Mass production
• loses of genetic diversity

Question 27

seed vaults

Answer 27

used to preserve seeds to protect biodiversity

Question 28

Categories of human activities driving biodiversity decline

Answer 28

1. Habitat loss.
2. Over-harvesting.
3. Species introductions.
4. Pollution.
5. Global Climate change

Question 29

Habitat loss is seen as the ______________________________________________

Answer 29

largest driver of human-caused biodiversity decline

Question 30

__________ of habitat loss are _________ when areas have _________________.

Answer 30

• Impacts
• greater
• high endemism

Question 31

define Endemism

Answer 31

species distributions that are limited to a small geographic area or ecologically distinct region

Question 32

Deforestation continues in some regions, but _____________________________________________ that experienced past forest loss from human activity.

Answer 32

forest cover is recovering in some locations

Question 33

Impact of _______________ has escalated with ________________________.

Answer 33

• over-harvesting
• technological advances

Question 34

___________________ has outpaced natural ________________________

Answer 34

• Capacity for harvesting
• capacity for recovery

Question 35

Today, _____________represent the species that are most in _________________________________________ of wild populations.

Answer 35

• fisheries
• danger of extinction from over-harvesting

Question 36

what is the global pattern regarding collapsed fisheries?

Answer 36

Steady increase in percentage of collapsed fisheries

Question 37

Introduction is happening at an ___________________________, and in a way that __________________________________________ — immediate introduction in a new range, instead of initial contact zone and geographic spread

Answer 37

• exceptionally high frequency
• differs from natural patterns of invasion

Question 38

what is shown in documented species introductions

Answer 38

• No sign in slowing down bc of increases
• so extinctions from introduction are likely to increase over time.

Question 39

define biomagnification

Answer 39

The process by which the concentration of a contaminant increases as it moves up the food chain

Question 40

____________ are particularly potent as agents of extinction.

Answer 40

Pesticides

Question 41

why are pesticides potent as agents of extinction?

Answer 41

Toxicity increases as the pesticide travels up the food chain

Question 42

Each consumer level of the food chain eats ______________________________________________________, with each consumed individual adding to the ____________________ in the body of the consumer

Answer 42

• many individuals from the trophic level below
• toxin accumulation

Question 43

Human-driven climate change is likely to be ____________________________________ - A very active area of ecological research

Answer 43

quicker than the capacity of many species to move and/or adapt