Studied by 5 people
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?
Mutations
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
Artificial selection
Convergent evolution
Embryology
Vestigial structures
Biogeographical distribution
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?
emergent layer
canopy layer
Understory layer
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?
Hawksbill Turtle
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?
Humpback Whale
Lear’s Macaw
Why were humpback Whales endangered?
Have always been hunted for a long time and eventually became endangered
Note 
Flashcard (37)