IB Environmental SL Test 2

Selective Pressures

Determine which individuals survive better

Gene Frequencies

Change resulting in natural selection

Directional Frequencies

For: One Extreme Against: Other Extreme

Stabilizing Freqeuncies

For: Moderate Traits Against: Both Extremes

Disruptive Frequencies

For: Both Extremes Against: Moderate Traits

Biodiversity

A measure of variety and abundance of species in a given area including genetic, species, and habitat diversity

Biodiversity Loss

Primary drivers are habitat loss, invasive species, over-exploitation, pollution, climate change

Population Bottleneck

Occurs when a population size is reduced for at least one generation and can reduce genetic variation significantly even if it is short

Structure of a community is described by:

Physical appearance, species diversity and abundance, and niche structure

Species Diversity (richness)

Decreases with increase in latitude, altitude, ocean depth (except bottom), and pollution in aquatic systems

Endemic Species

Species that are only found in one isolated area

Nonnative vs. Invasive Species

Invasive dominates the landscape, nonnative only aren’t in an environment in which they evolved to live and thrive

Indicator Species

Serve as early warnings of damage to a community or ecosystem

ex. trout, amphibians, immigrating birds, lichen

Primary Succesion

Bare rock

Pioneer Species

First living thing after primary succession, often lichen

Secondary Succession

No living things but there is already a developed soil

Number of recorded mass extinctions

5

Mass Extinction

More than 50% of species disappear in a relatively short period of time

Background Extinction Rate

The predicated Extinction Rate based on fossil records. Estimated 1 in every million species goes extinct each year, 1 mammal every 200 years. Current extinction rate 100-1000 times greater than background

Extinction Causes

Combinations of: meteorite, habitat loss, climate change, glaciation, geological events (volcanoes), ancient plate movements, and geographical changes.

Convention on International Trade in Endangered Species (CITES) 1973

Made by International Union of Conservation of Nature (IUCN). Forbids trade of 900 different specimens or wildlife products, restricts trade of 29,000 other threatened species, maker of “red list” of threatened species

Convention on Biological Diversity 1992

Legally binds signatory governments to reversing the global decline in biodiversity with objectives of conserving biodiversity, sustainably using biodiversity, and equitably sharing all the benefits that emerge from commercial use of biodiversity

Lacy Act of 1900

Enacted to combat the impact of hunting so supply commercial markets, interstate shipments of unlawfully killed game, and killing of birds for feather trade.

Prohibits the movement of dead or alive wild animals across state borders without permit.

Marine Mammal Protection Act 1972

Prohibits killing of all marine mammals in the US and the import or export of their body parts

Endangered species Act 1973

Illegal for Americans to import or trade any product made from an endangered species. Lists all endangered species both in the US and foreign. Endangered species cannot be hunted, killed, injured, or collected in the US. Prepares a recovery plan to increase the population size of each endangered species.

Island Biogeography Theory

Used when designing nature reserves. Islands are ideal places for unique species to evolve due to isolation but are also places on concentrated extinction because of low population sizes

Island Equilibrium Point for Species Diversity

Immigration = Extinction

Island Biogeography Uses

Help biologists locate areas in greatest danger of species diversity loss, estimate the size of the nature reserve used, evaluate how close the reserves need to be to allow immigration, and assess the size and number of protected corridors

Nature Reserve Design Criteria

Circular for more inner core, single large over several small for less edge space, heterogeneous diversity for many habitat types, incorporation of community, buffer zones for inner core and corridors.

Captive Breeding

Stimulates natural habitat and doesn’t tame wild animals. Breeds with purpose of reintrduction into the wild

Plant Protection

Botanical gardens and seed banks around the world including the Global Crop Diversity seed bank in Norway

Ecocentric

​Nature-centered, environmental, social and spiritual aspects are integrated. Self-reliance, self-restraint and minimal disturbance of the natural processes to achieve sustainability for the whole earth.

Anthropocentric

People centered approach, where people monitor their own environment with some help from authorities and population control and resource management equal importance.

Technocentric (Cornucopian)

Technology will keep pace with development and exploitation of the planet and scientific research and technology will allow us to keep moving in the direction we’re headed

Precautionary Principle

Need to protect a natural resource even if we don’t know all the cause and effect relationships