unit 3 all cards combined

age of an old area

An older area tend to have higher biodiversity

Environmental stability

Areas that have experienced environmental disturbance or climate disturbance have less time for colonization

Range of habit

A wide range of habitats will allow organisms to move into new habitats and ecological niches

Altitude Variation

Any area with a mountain range will have a range of climates associated with the different heights and so there are different organisms on each zone

Latitudinal Ranges

Areas that extend across the latitudes will have the same sort of variation as seen in mountain ranges

Variation in rock and soil type

Changes in the abiotic environment will cause changes in the biotic environment

Benefits of Biodiversity

• biodiversity maintains genetic diversity and thus is important to continuation of evolution

• humans benefit financially from biodiversity. Natural capital gives us goods that. And be extracted, processed and sold

Genetic Diversity

The variation of gene within the genetic pool of a population of a specific species

Why is genetic diversity impossible

• Extinction is frequently preceded by a drop in genetic diversity

• Once lost a genetic diversity is impossible to regain

Habitat

The abiotic and biotic environment a species usually lives in

Habitat Diversity

The range of different habitats in an area

Terrestrial Bioma

Abiotic factors more important to the plants

• Temperature range, soils type, light

Marine Habitats

They are transient and changeable and it’s not just the vegetation that provides habitat for animals

• Mostly depends on abiotic factors

Charles Darwin and Alfred Wallace

Introduce the idea that if you take any two creatures on Earth and trace their ancestry back far enough you will find a common ancestor

What is the common ancestor of all life?

A simple single-cell organism

Evolution

The change in genetic composition

What are some causes of evolution?

1. Mutations

2. Natural selection

Mutations

A change in DNA and it can be a single change or multiple changes

Natural selection

The process where organisms adapt to their environment to survive and produce more offspring (main process of evolution)

Evidence of evolution

1. Artificial selection

2. Convergent evolution

3. Embryology

4. Vestigial structures

5. Biogeographical distribution

6. Fossil record

Artificial selection

the process by which humans choose individual organisms with certain phenotypic trait values for breeding

Convergent evolution:

Where similar structures have evolved independently in different organisms without the presence of a common ancestor

Embryology

As embryos develop, the similarities are lost as structures differentiate

Vestigial structures

These are parts of an animal that no longer serve any purpose but they serve as reminders of what the organism evolved from

Fossil record

shows the changes in organisms over time as the organisms’ structure can be compared to past and present species, thus allowing the construction of a tree of life.

Speciation

The formation of a new species through biological processes

Geographic isolation

Populations are physically separated and can no longer interbreed

Temporal Isolation

Populations live at different times of the day and so do not meet to breed.

Behavioural Isolation

They have different mating rituals

Variation

 a different or distinct from or version of something

Inheritance

a thing/ trait that is inherited

Comparative advantage

Many organisms are r-strategists, that is they produce more offspring than can be supported in the local habitat

Differential survival and reproduction

Variation is caused by random genetic mutations that may or may not be beneficial to an individual.

Survival of the fitness

a useful concept as it encompasses the most important aspects of natural selection: survival and reproductive success (secure a mate to reproduce and pass your genes on to the next generation).

Plate tectonic

a  theory that explains the motion of the earth’s lithosphere (outer layer) and the impact that has had on the distribution of the continents

what are the two type of Plates

• continental

• Oceanic

Continental plate

lighter in colour and density

Oceanic Plate

darker and denser

Divergent plate boundary

occurs when two tectonic plates move away from each other

Convergent plate boundary

When two plates come together

Divergent plate margins

where plates move apart and this creates opportunities for diversification

Convergent plate margins

As plates move together, they create mountains, volcanoes, land bridges and massive ocean trenches

Transform plate boundary

where plates slide past each other

Volcanic activity

creates new habitats and niches both on land and in the oceans

Mass extinction

a sudden global decrease in the number of species over a relatively short period

Background or normal extinction

the standard rate at which species go extinct

Ordovician-Silurian mass extinction (440 million years ago)

Earth was in the oceans so marine organisms were hit hardest by this extinction with over 80% of them being wiped out

Permian mass extinction (250 million years ago)--> "The Great Dying"

Biggest extinction ever in Earth’s history destroying 96% of the planet

Cause: bolide impacts (meteors that burn up in the sky), ;arge volcanism or large release of methane from the sea floor

Triassic-Jurassic mass extinction (200 million years ago)

in the final 18 million years of the Triassic period approximately half of all known species went extinct. This vacated terrestrial niches and allowed the dinosaurs to take over
Causes: climate change (volcanic eruptions), asteroid impact, sea level fluctuations

Cretaceous-Tertiary mass extinction (65 million years ago)

wiped out the dinosaurs (around 80% of all life on Earth was made extinct). 

The key fact here is that many mammals and birds survived and were able to take over the niches previously occupied by the dinosaurs

Cause: an asteroid hit the Yucatan peninsula in Mexico

Sixth (Holocene) mass extinction (right now)

Humans are definitely killing off species and many scientists agree we are doing so thousands of times faster than nature is creating them

host-specific species

 to intensively count the number of species in one area and then extrapolate this to a wider area

Ratio of Temperate and Tropical Species

based on fairly extensive knowledge of numbers of temperate species

Taxonomic Classification System

Groups of organisms according to observed/ physical similarities in their characteristics

Disadvantages of directly counting the number of species globally

• Groups of species that are small are difficult to isolate

  • Bacteria
    

• Some species are difficult to access

  • Deep sea organisms

• Some species might be extinct before we know about their existence

Unknown species

There are more species such as terrestrial or birds that we know more about compared to others

How humans can threaten species: directly

through hunting or harvesting

How humans can threaten species: indirectly

activities leading to destruction or degradation of habitat and also, actions that contribute to climate chang

Over-exploitation of resources

Renewable sources (animals, fishes, and plants) need to be managed sustainably to secure a continued supply (Need time to re-generate)

Habitat Fragmentation, Degradation, and Loss

Forests have been exploited for years → for construction materials, firewood, food, medicine

Developing countries

The increase in the demand for food makes it to be a lot of farming that needs to happen to feed the population 

Invasive species

Humans have desired species around the world for their personal use

mining

Fragmentation of habitats through the development of roads to transport the mined goods and for movement of the workforce and other materials

How are aquatic habits polluted?

through discharges of wastewater, degrading habitat and its species

How are terrestrial habits polluted?

disposal of waste on land can contaminate the ground and degrade the habitat

Fly tipping

the illegal disposal of household, industrial, commercial, or other 'controlled' waste

Atmospheric pollution

can lead to a change in some localized groups of species, such as lichen (some species are intolerant to air pollution)

Climate change

 Human activities increase the number of greenhouse gases (carbon dioxide) which increases the overall global temperature

IUCN

The International Union for Conservation of Nature

The IUCN Red List

 Red List uses a range of criteria to evaluate whether a species is under threat objectively and according to this level of threat is designated a specific category

Criteria to determine conservation status of species: Population size

number of mature individuals (the animals that are able to reproduce)

• Smaller population: lower opportunity to breed successfully (risk of extinction)

Criteria to determine conservation status of species: Geographical range

extent of occurrence and area of occupancy (where species are normally found)

Criteria to determine conservation status of species: Number of Location

Variety of threats to species and habitats discussed in the previous section, and the number of locations a species is found in may decline

Criteria to determine conservation status of species: Probability of extinction

predicted likelihood of all the populations of the species in the wild dying out in the future

Criteria to determine conservation status of species: Quality of habitat

contributes to the survival and success of a species

Criteria to determine conservation status of species: Extent of habitat fragmentation

Often occurs through human activities such as urban development and roads

What are two extinct species

• the Dodo bird

• Tasmanian tiger

What was the Dodo like before humans?

The numbers of Dodos were high due to the lack of natural predators

What are some characteristics of the Dodo?

Was a flightless bird and nesting on the ground made it easy prey to its new predators

Why did the Dodo go extinct?

• Humans Hunting the bird for meat

• Invasive species: dogs, monkeys, pigs, and rats who attacked the nest and eat the eggs

• Human exploitation of forest resources, destroying the forest habitat

What was the Tasmanian tiger like before humans?

Population was already considered to be low 

What are some characteristics of the Tasmanian tiger?

Carnivorous marsupial that had a pouch which had similar characteristics of a dog

• Feed on kangaroos and other marsupials, rodents, and birds

• Sheep was another pray that came when the Europeans settle in Australia

Biological hotspots

Regions that contain a high level of species diversity, many endemic species and numerous threatened or endangered species

Tropical Rainforest Biomes

Cover roughly 6% of the land surface and are the most rich and diverse biomes.

What are the different horizontal zones of the rain forest?

1. emergent layer

2. canopy layer

3. Understory layer

4. forests floors

Emergent layer

The highest layer

Canopy layer

fairly dense and significantly reduces light penetrating further into the forest

Understory layer

below the canopy layer

Forests floors

Receives less than 2% of the light 

Rainforest goods

food, timber, medicine,

Rainforest service

Absorbing CO2, producing oxygen

What is Papua New Guinea under threath?

• Commercial logging 

• Mining activities

• Agriculture

• Population growth

What are two critical endangered species?

1. Hawksbill Turtle

2. Sumatran Orangutan

What are the hawksbill turtle used for:

• Traditional medicine

• Shells used for religious ceremonies

• Made into jewellery and ornaments

• As a symbol of wealth and social status

Reasons for the endangerment of the Hawksbill turtle

• Reduced nesting sites due to coastal development, leading to loss of sandy beach and habitation by humans.

• Pollution, such as ingestion of plastic debris resulting in blockage of the digestive system and subsequent death

• Accidental capture in fishing nets.

Reasons for the endangerment of the Sumatran Orangutan

• Logging leading to habitat loss

• Use of land for oil palm plantations and agriculture, leading to habitat loss.

• Fire is used to clear forests for other land uses, which can directly kill the slow-moving orangutans.

What were the Sumatran Orangutan like before humans?

Found throughout the whole Island, Sumatran orangutans are now restricted to the provinces of North Sumatra and Aceh

What are two improved Conservation Status?

1. Humpback Whale

2. Lear’s Macaw

Why were humpback Whales endangered?

Have always been hunted for a long time and eventually became endangered