APES Chapter 11 – Biodiversity

total organisms in an area

biodiversity

differences in DNA among individuals within a species

genetic diversity

What does genetic diversity lead to? (2)

1. natural selection

2. adaptations

What does a lack of genetic diversity cause? (2)

1. vulnerability

2. inbreeding depression

the reduced survival and reproductive success of a population due to breeding between closely related individuals, which increases the likelihood of harmful recessive traits

inbreeding depression

diversity of a habitat in a given unit area

ecosystem diversity

name 3 importances of biodiversity

1. ecosystem services

2. ecosystem function

3. food security

4. drugs and medicines

5. economic benefits

6. people value nature

name 3 ecosystem services

1. food

2. shelter

3. fuel

4. cycling nutrients

5. aesthetic benefits

ecosystem functions of biodiversity (2)

1. resilience/stability of ecosystems

2. controls population sizes

Why does biodiversity lead to increased food security?

it creates disesase-resistant crops

one economic benefit of biodiversity

ecotourism

name 2 challenges of species richness

1. lack of exploration

2. microscopic species

3. similar species

The normal, natural rate at which species go extinct over time

background extinction rate

What happens when current rate of extinction is larger than the background rate of extinction?

biodiversity decreases

a global inventory that assesses species’ extinction risk and classifies them into categories, such as Vulnerable, Endangered, and Critically Endangered, to help guide conservation efforts

IUCN Red List

species richness is greater near the equator

latitudinal gradient

the study of how an island’s size and distance from the mainland affect its species diversity, with larger and closer islands generally supporting more species

island biogeography

the number of species on an island reaches a balance between immigration (new species arriving) and extinction (species disappearing), influenced by the island’s size and distance from the mainland

equilibrium theory of island biogeography

fewer species on far islands

distance effect

large islands have more species

area effect

When the edges of a habitat have different environmental conditions than the interior, affecting which species can survive there.

edge effect

name 6 causes of biodiversity loss

1. habitat alteration

2. invasive species

3. pollution

4. population

5. overharvesting

6. climate change

study that seeks to understand loss, protection, and restoration

conservation biology

the smallest number of individuals a species needs to survive long-term without going extinct

minimum viable population

a downward spiral in which a small population experiences reduced genetic diversity and lower reproductive success, making it increasingly vulnerable to extinction

extinction vortex

2 biodiversity protection approaches

1. single-species approach

2. ecosystem approach

wildlife corridor

single-species approach (can affect ecosystem)

A popular or charismatic species used to raise public awareness and support for conservation efforts

flagship species

A species whose protection indirectly protects many other species sharing its habitat

umbrella species

flagship species

single-species approach (can affect ecosystem)

umbrella species

single-species approach (can affect ecosystem)

2 defining characteristics of a biodiversity hotspot

1. containing at least 0.5% of the world’s endemic species

2. have lost at least 70% of their original natural vegetation due to human activities

no destroying endangered species/habitats

endangered species act

bans international transport of body parts

CITES

prohibits transport of illegally captured or prohibited animals across state lines

lacey act

What does the latitudinal gradient cause? (2)

1. increased solar energy → higher GPP

2. stable climate

What does the edge effect lead to?

habitat loss