Australian Biota

1. Evidence for the rearrangement of crustal plates and continental drift indicates that Australia was once part of an ancient super continent

1.2.1 Identify and describe evidence that supports the assertion that Australia was once part of a landmass called Gondwana, including:

Matching continental margins Position of mid-ocean ridges Spreading zones between continental plates Fossils in common on Gondwanan continents, including Glossopteris and Glangamopteris flora, and

marsupials Similarities between present-day organisms on Gondwanan continents

Crustal Plates move over time Theory of plate tectonics states: Earth crust is divided into several big, rigid plates that are made up of

continents and ocean basins. Plates can move apart, slide past one another or collide Continents were once part of an ancient super continent. Over time they drifted apart and split. Part of evidence of continental drift theory comes from study of Gondwana Gondwana was a large landmass of southern continents (including Australia) that split from the super

continent

Evidence that Australia was once part of Gondwana Evidence comes from evidence that supports crustal plate movement and continental drift

Matching of continental margins Evidence of rifting & drifting comes from ways continents fit together and continuity of rocks between their

opp edges. The geometric & geological fit can be seen between South America and Africa. Shaded areas show areas of

matching rock that have been radiometrically dated to an age more than 2 bil yrs.

The position of mid-ocean ridges and spreading zones between continental plates Mid-ocean ridges form the boundaries of Earth’s crustal plates where the plates move apart. Crusts move cos lava (hot molten rock) is added at these ridges Active volcanoes and shallow earthquakes occur here too Seafloor spreading occurs where 2 crustal plates move apart. Hot molten material rises into the gap. When

this material cools and becomes rigid it forms part of the plates on either side of the spreading zone. Earth doesn’t seem to be expanding. So if new crust is being added at spreading zones, it must be destroyed

at other places.

Fossils in common on Gondwana continents Glossopteris and Gangamopteris are distinctive Plants from the Permian age- fossil remains of these plants have been found on all Gondwana continents.

Not found on others.

Similarities between present day organisms on Gondwana continents The floras of southern continents- South America, South Africa, Australia and New Zealand have many

features in common. E.g. the family Myrtaceae includes the plant genera Eucalyptus, Callistemon, Melaleuca and Leptospermum. Myrtaceae are widespread through AUS (50 genera), South America (27 genera) and southern Asia.

The family Proteaceae includes the plant genera Banksia, grevillea and Telopea. Proteaceae are found in New Zealand, South America and South Africa.

1.2.2 Discuss current research into the evolutionary relationships between extinct species, including megafauna and extant Australian species

Mammals Monotreme: mammals that lay eggs eg. platypus Marsupial: have a pouch, baby born undeveloped eg. kangaroo Placental: higher order organism, slightly more advanced

Evolution of species in Australia Flora & fauna that associate w Australia are restricted to continents of southern hemisphere. Australia → unique/distinct environmental pressures/conditions|evolution in isolation isolation of Aus. as island continent = monotreme/marsupial survival (lacking competition from placentals)

also reduced competition amongst themselves by occupying different niches and often developed specialised diets

fossil evidence → mammals evolved from reptiles 200m mya Aus. marsupials evolved in isolation until 50mya ( up till humans) → great number different types, wide

range environments Evolution of life has give rise to about 500mil animal species since life began. Extant species number about 3-4mil. Examples of extinct megafauna Wonambi- a giant snake, megalania- a lizard which grew up to 6-7m in

length, diprotodont- a large wombat like marsupial, at least as big as a rhinoceros. during last 1.64my many backboned animals (marsupials, reptiles) became very large → megafauna some megafauna survived until last 20,000years; now EXTINCT megafauna NOT believed to be direct ancestors of present marsupials/reptiles related; evolved from COMMON ANCESTOR in distant past

1.3.1 Solve problems to identify the positions of mid-ocean ridges and spreading zones that infer a moving Australian continent

Evidence that the Aus continent is moving at 5-6cm per year in a North-East direction has been obtained using modern technology.

Before this, the movement of the continent was inferred from the position of the mid-ocean ridges, particularly those to the south of Aus and the fact that the sea floor was spreading on either side of the ridge.

The fact that Aus and Antarctica split up fairly recently supports the explanation.

1.3.2 Identify data sources, gather, process and analyse information from secondary sources and use available evidence to illustrate the changing ideas of scientists in the last 200 years about individual species such as the platypus as new information and technologies became available

The platypus Was first described in 1799 in Shaw’s Naturalist’s Miscellany along with the koala, kangaroo, wombat, emu. Since first discovered-lots of debate as to whether it’s a mammal and how it should classified.

Platypus – primitive mammal lays eggs absence of true teeth absence of true mammary glands BUT special glands that secrete milk fur BUT has horny beak [like the bill of a duck] webbed teeth tail like a beaver

Up until 1884 there was uncertainty about how the platypus reproduced. Caldwell solved the problem by capturing a female with eggs

About 1904- the scientific American reported that there are many mammals that do not possess teeth when adults

2. The changes in Australian flora and fauna over millions of years have happened through evolution

2.2.1 Discuss examples of variation between members of a species

Variations: small differences btwn organisms belonging to the same species features – size/colour various body parts biochemical

differences important in evolutionary terms when environmental change occurs variation in population = chance some members will be able to survive

White-naped honeyeater Melithreptus lunatus eastern Australia → short bill, orange-red eye patch lunatus western Australia → larger bill, white or green eye patch whitlocki, chloropsis cannot interbreed (geographically isolated), subject to different environmental conditions. They might

evolve eventually into a different species

2.2.2 Identify the relationship between variation within a species and the chances of survival of species when environmental change occurs

environmental change → climate hot/cold/wet/dry → distribution/abundance living things changes organisms w favourable variations may survive changes and bring about change in species by natural

selection

2.2.3 Identify and describe evidence of changing environments in Australia over millions of yearsChanging climate

65mya: when AUS and Ant. Were still joined together, climate=cool and wet temperate rainforest 45mya Aus. completed separation from Antarctica WIND PATTERNS CHANGED, became cooler/drier As Aus drifted nth, gradually became warmer → rainforest area shrank, other types vegetation increased As AUS moved north of tropic of Capricorn, climate in north became tropical. warmer, wetter periods when forests expanded | cooler, drier periods where grasslands increased overall Aus. has become warmer/drier, particularly inland In last 120 000 years has been a warm period during which fire is significant environmental feature.

Changing landscape sea levels risen and fallen

Tasmania joined mainland 8 times in past 30my erosion continued, lowering land surface → Australia flattest continent 35mya volcanic activity created extensive lava flows around east coast 20mya Eastern Highlands uplifted

Changes in distribution and abundance warmer/drier = living things evolved w adaptations to survive increasing aridity adaptive radiation: transforming of species to survive in new environment e.g. acacias (wattles) and

eucalyptus 950 species acacias found almost everywhere, 800 species eucalypts found mainly in forests/open

woodlands 35 types Proteaceae endemic to Australia banksias, grevilleas, hakeas, waratahs 3 types mammals – placentals, marsupials, monotremes

→ fossil record = placental mammals, apart from bats, died out→ placentals didn’t reach AUS until AUS drifted close to Asia for colonisation to occur in north.→ marsupials diversified and flourished, now 141 species

frogs → wide variety habitats → lack of dependence on H2O → breed in temporary pools → brief tadpole stage

Theories about changes to Australian species Riversleigh, NW QLD rainforests to dry habitats fossils dating from Miocene to Pliocene period Naracoorte, SA [fossils from Naracoorte and pollen data from nearby Wylie swamp] during Quaternary, inland lakes dried up, vegetation changed from forest to open woodland fossils found give clearer picture of evolution of ecosystems to warmer and drier conditions world heritage areas b/c fossils already found and continuing research will greatly contribute to knowledge.

2.2.4 Identify areas within Australia that experience significant variations in temperature and water availability Australia surrounded by ocean w greatest land width along tropic of Capricorn, 5.6m km2

Temperature inland temp range wide bc heat from day rapidly lost at night generally sub or tropical temp only in SE and SW are mild and temperate conditions inland deserts/grasslands

→ summer 40°C day, cool night→ winter 20°C day, sub-zero night

Rainfall Aus is worlds driest continent 75% receives lass than 800mm annually Inland Australia, most of west coast- low unreliable rainfall. All seasons are dry.

common pattern over large areas = droughts and erratic rainfall followed by floods water availability a problem over large areas many temporary water bodies unpredictable levels/flow of rivers/creeks common pattern is floods followed by drought

Anticyclones are large dry air masses located over inside Aus. Move south in summer and attract warm, moist air from equatorial regions (monsoon). Areas in north of Aus has monsoonal climate- wet and dry season.

2.2.5 Identify changes in the distribution of Australian species, as rainforests contracted and sclerophyll communities and grasslands spread, as indicated by fossil evidence

Early European explorers hadn’t seen interior of Aus but thought it would be fertile like coast. First realised dry arid nature by Baldwin Spencer in 1894 as climatic conditions changed so did Australian biota

increasing heat/aridity favoured plants/animals tolerant of such conditions → spread out, increased in numbers

plants that could not tolerate conditions were restricted in distribution and abundance rainforests contracted, all tall forests became restricted to edge of continent [rainfall from ocean] schlerophyll communities and grasslands increased over time → thick, waxy – reduce water loss

most common rock surface sedimentary → fossils indicate vast changes in distribution/abundance of species jenolan caves – limestone – once covered by warm, shallow oceans; contained numerous types corals,

molluscs, fish species once in rainforests almost covering Australia now reduced to 22,500km2

→ distribution/abundance drastically reduced [bats associated w such rainforests] Thylacine (Tasmanian tiger)

Lived in Kimberley’s up until 80ya 3000ya in southern half of main land In New Guinea until 10000ya 5 different kinds of identified at Riversleigh

Rocks at Geilston bay= fossils 22-23 mya. These fossils were possum like marsupials, native cats and diprotodonts.

Huge marsupial fossil at Naracoorte 40000mya.

2.2.6 Discuss current theories that provide a model to account for these changes continental drift

→ climate changes and changes in environment have changed distribution/abundance of species natural selection

→ explains how some species survive and adapt to changes in environment adaptive radiation

→ explains how species can spread out to occupy different habitats

2.2.7 Discuss Darwin’s observations of Australian flora and fauna and relate these to his theory of evolution Darwin’s visit from January to March 1836- about natural selection. These were examples taken from his observations of Aus flora and fauna to support his theory of evolution.

crow like the jackdaw bird like the magpie potoroo like the European rabbit platypus like so many water rats fly and ant fell into trap of ant lion → larva belongs to same genus, but different species from European one Darwin and Wallace published views in the same journal in 1858. Darwin published book origin of the

species in 1859- Darwin given more credit than Wallace b/c he had more comprehensive and decisive evidence.

NATURAL SELECTION (mechanism) theory of evolution BY natural selection

1. w/in any species there is variation appearance/behaviour2. offspring w favourable traits/variations will survive to pass those traits on to offspring3. organisms w less favourable traits will not survive to reproduce – their traits are lost to the gene pool4. those surviving organisms reproduce, their traits become predominant in population survival of the fittest

→ fittest = reproductive capacity of individual as well as being healthy/well adapted to environment

→ Darwin and Wallace argue that evolution could be brought about by a mechanism in which competition and environmental pressures naturally selected the best adapted individuals called natural selection

Most of the time natural selection was extremely slow but not with the peppered moth.

Peppered moth white form more common → camouflaged against white lichen that covered trees of its habitat industry lay soot over lichen → black moth abundant due to better camouflage → white fell prey to birds in recent times production of soot decreased, proportion of white moths in population increased

Different organisms Similar environments Similar adaptations

DDT: used to control insects, crops, mosquitoes. Now insects are becoming resistant to DDT mutations due to natural selection. It would take hundreds of years to observe similar changes in humans b/c takes many years to reach sexual maturity and we have very few offspring.

Mutation: spontaneous and permanent change in DNA after natural selection there were still black and white moths [no new species evolved] in the case of the apple maggot fly a new kind of fly that infested apples evolved

→ two species evolved bc two groups of flies could not mate→ became isolated from each other bc one favoured hawthorn while the other preferred apples→ for any new species to evolve groups of organisms need to become isolated from each other.

Geographic isolation: e.g. Gondwana separated 100mya. Species isolated b/c continents drifted apart. Each had different

environmental conditions and new organisms evolved by natural selection. East coast geographically isolated from west coast Aus by desert (used to be lush vegetation). Species have

slight differences from east to west.

Adaptive radiation: organisms spread into new habitats and over millions of years evolve, adapting to environments they inhabit.

E.g. after extinction of dinosaurs, mammals occupied many vacant niches in ecosystems. Primitive marsupials spread throughout Australia and adapted to various conditions.

Divergent evolution: one consequence of adaptive radiation is divergent evolution. 2 orgs from same common ancestor move to dissimilar environments; gradually different species Divergent evolution explained by natural selection and isolation. Physical barriers: mountain ranges, deserts, inland seas/water barriers. Different species evolved due to

isolation. Had diverged into different species with its own characteristics.

Convergent evolution: 2 orgs from dissimilar ancestors come together in same environment; gradually look more similar

Result of natural selection and isolation eg. sharks and dolphins e.g. thylacine evolved to occupy similar niche/environment to lions and tigers on other continents Aus glider possums and USA’s flying squirrel.

Punctuated equilibrium: the view of evolution occurring rapidly followed by an extended period of stasis. Theory by Gould and Eldridge. Evolution occurred as spurts

→ Extinction of dinosaurs may be consistent with this theory After major catastrophe → rapid periods evolution (50,000 – 100,000yrs) followed by extensive periods

stability Darwin: gradualism → small changes in organisms after a long time period. Doesn’t believe in spurts. He

reckons the fossil record is incomplete so doesn’t show gradual transitions that have occurred.

2.3.1 Gather, process and analyse information from secondary sources to develop a timeline that identifies key events in the formation of Australia as an island continent from its origins as part of Gondwana

2.3.2 Gather information from secondary sources to describe some Australian fossils, where these fossils were found and use available evidence to explain how they contribute to the development of understanding about the evolution of species in Australia

2.3.3 Perform a first-hand investigation, gather information of named Australian fossil samples and use available evidence to identify similarities and differences between current and extinct Australian life forms

Fossils of the extinct plants Glossopteris and Gangamopteris resemble present day ferns and their venation but apparently reproduced by seeds.

2.3.4 Present information from secondary sources to discuss the Huxley- Wilberforce debate on Darwin’s theory of evolutionWilberforce was outraged by Darwin’s theory, particularly by the idea of a link between man and apes. He felt it was against religion. Huxley was one of Darwin’s most important advocates. In 1860, Huxley and Wilberforce had a famous evolution debate. Wilberforce asked whether it was one his father or mother’s side he was descended from apes. Wilber felt evolution was ridiculous. Significance of debate was that the established views of church have been challenged.

3. Continuation of species has resulted, in part, from the reproductive adaptations that have evolved in Australian plants and animals

3.2.1 Distinguish between the processes of meiosis and mitosis in terms of the daughter cells produced

MEIOSIS cell division; parent cell produces 4 non-identical daughter (germ cells – egg/sperm) w haploid-23

chromosomes occurs in cells of sex organs reduction in amt genetic material comprises 2 successive nuclear divisions with only one round of DNA replication REPRODUCTION: producing variation in gametes (sex cells) so all offspring are dissimilar

MITOSIS cell division; parent cell produces 2 identical daughter cells w diploid-46 chromosomes

→ growth/repair – replace dead cells asexual (one parent) reproduction

→ yeast – budding→ bacteria – binary fission (splitting into 2) *IDENTICAL

Interphase (resting stage)Chromosomal material = long, thin, drawn out threads

(replication takes place between, nuclear membrane dissolves

Prophase4 chromatids, 8 chromosomes → chromosomes have replicatedNuclear membrane disappears

MetaphaseChromosomes align at equator/equatorial plateCentrioles migrate to poles and produce spindle fibres (protein) → hook onto chromatids and pull apart chromatin = 60% protein, 40% DNA – make up chromosome

AnaphaseSister chromatids separate (drawn apart by centrioles/spindles)Centromeres divide

Cytokinesis- division of cytoplasm/organelles

Telophase Nuclear membrane reforms genetically identical to parentPlant cell build new cell wall, animal cells = 2 new identical cellsDaughter cells

(MEIOSIS)

Synapsis: side-by-side pairing of homologous maternal and paternal chromosomesCrossing over: two homologous chromosomes break at equivalent positions and then join to produce recombined chromosomes – exchange of genetic material

3.2.2 Compare and contrast external and internal fertilisation Internal External

Differences no. gametes improved chance fertilisation

wastage of gametes/energyNo egg shell

no. gametes improved chance fertilisation but the fertilisation per egg ratio is very low.

wastage of gametes/energyEgg shell to decrease desiccation

Similarities Courtship for synchronisingNeed moist env.Need gametes (egg/sperm) to come into contact

Season conditions for synch – H2O temp, moon phase

External fertilisation: needs a watery env. so sperm can swim to an egg. Limited to animals that live in aquatic env. E.g. fish (not sharks), amphibians, coral polyps. Developing embryos need watery env. external fertilisation very chancy.

Internal fertilisation: Occurs in some vertebrates e.g. mammals, birds and reptiles. Reptiles, monotremes and birds have shelled eggs. Female marsupials and placental mammals retain eggs in body.

3.2.3 Discuss the relative success of these forms of fertilisation in relation to the colonisation of terrestrial and aquatic environments

Aquatic env. External

→ high success due to adaptations fish Internal:

→ high success due to close gametes mammals Terrestrial env.

External: → desiccation is a problem – gametes would dry out and die; if go back to H2O successful

amphibians Internal:

→ High success due to close gametes and presence of H2O

3.2.4 Describe some mechanisms found in Australian flora for: Pollination Seed dispersal Asexual reproduction

Reproduction in flowering plants and conifers involves 2 kinds of gametes- pollen and eggs. Gymnosperms- cone bearing plants that have naked seeds not enclosed in ovary. Mostly wind- pollination. Angiosperms- flowering plants with seeds that develop from an ovary which upon fertilisation becomes a

fruit.PollinationPollination: transfer of pollen from anther of flower of one plant to stigma of flower of another plant

Cross pollination – transfer of pollen between one conifer and another (different flowers); advantageous – variationFertilisation – pollen grains lodge on stigma of a flower. Pollens carried by following means:

→ Blown by wind→ Carried by animals e.g. insects, birds or mammals.

Wind pollination Pollen= small, smooth and very light. These flowering plants don’t have brightly coloured flowers, stamens are exposed to wind, feathery stigmas

catch passing pollen grains. Chancy, hit and miss, affected by climate.

Animal pollination Most flowering plants are pollinated by insects, birds or mammals. Animal carriers of pollen called vectors and ‘rewarded’ by plant – food (sugar- nectar, protein- pollen)

Mechanisms include- Bright colours (insect pollinated flowers are blue, purple or yellow), (bird= red, orange or yellow) - animals push through pollen to get nectar- Perfumed flowers – attractive odour. E.g. moths at night. Not birds- they rely on vision instead of

smell.- Sugar rich nectar to attract insects- Shape of flowers – platform like structure where insects can land.- White or yellow dots to reflect UV rays so insects can see.- Honey possum – Banksia flowers. They’ve got a long, brush tipped tongue to mop up nectar. - Some plants pollinated by one insect species may have a shape that mimics shape of female of that

species and so attracts male insects to flowers. Gets covered in pollen.

Seed dispersal (plants are sedentary) Fertilisation of an egg by pollen occurs within ovary. An embryo forms within a seed that protects it and

provides a food store for use at the time of germination. Seeds may be soft and fleshy or a hard nut. They can be large like coconuts or tiny like orchid seeds.

Dispersal of plants occurs only at seed stage of life cycle. Water (have water proof coat and buoyant)

→ raindrop splash→ wash (thunderstorm)→ river

Wind→ Seeds are blown. Light weight.→ strategies include

parachutes dandelions, thistles helicopter action maples and grass seeds

Animal (some have hooks or spines that help them attach to fur or feathers. Some hitch hike inside animals-they eat them) → Birds

cockatoo carries fruit pigeons pass seeds through tract

→ Bats flying fox

→ Foxes blackberries in gut burrs on hair

Asexual reproduction

A piece breaks off and grows into a new plant

Producing offspring genetically identical to parent (requires only one parent). By mitotic cell division.→ rose→ Willow→ Corms – underground stems

Iris→ Bulbs→ Stolons – above ground horizontal stems

Kikuyu (grass)→ Tubers

Potato→ Runners

Strawberry Advantages

→ One parent – no isolation→ Rapid colonization of an area

Disadvantages→ Too similar if env. changes

3.2.5 Describe some mechanisms found in Australian fauna to ensure: Fertilisation Survival of the embryo and of the young after birth

Ensure fertilisation Courtship behaviours (specific) Some orgs have specific reasons to breed Lyre bird and bower bird have elaborate displays and calls to attract mates. Most kangaroos can breed all year round if food is available. This increases chance of fertilisation. Shortness of some breeding cycles e.g. bandicoot and dunnart. (marsupial) Some dessert lizards reproduce without fertilisation by parthenogenesis. (unfertilised eggs)

Survival of the embryo and young Kangaroos

Red kangas: developing embryo in uterus can lie dormant if conditions are not favourable and begin again once they’re good this is embryonic diapause. This also occurs after a fetus is born and a second embryo starts to develop. The second embryo is held in storage till the first one leaves the pouch. Red kangaroo produces 2 different kinds of milk- suited for each joey. They can even have one at foot, one in pouch and one in storage.

Large amts energy put into infants to increase chances of survival Female kanga can close pouch if danger arises.

Some species of frogs lay eggs on land and bypass tadpole stage- develop directly to frogs. Marsupials=lower metabolic rate than marsupials so can survive on lower nutrient intake. Can be

advantage. Marsupials: embryos are in uterus for less time so born not as developed as placental mammals. Less

wastage of energy if offspring dies. Placental mammals spend lots of time and energy and nutrients in off spring before they’re born but if

they die it’s a big waste. Seasons of Australia are unpredictable so animals are adapted to survive if land is dry and barren or after

rain.3.2.6 Explain how the evolution of these reproductive adaptations has increased the chances of continuity of the species in the Australian environment

1. Family groups – increase care. Remain together for long periods to raise young. Members in family groups help to support each generation.

Kangaroo, bluewren, kookaburra2. Partner for life – understanding of expectations (who does what)

Wedgetail, cockatoo, swan

3. Breeding rights Valuable for females to mate w many males → gives offspring genetic diversity with ½ her genes Valuable for males to mate w many females → increase his genetics in the population They maintain a harem (group of females w one male) e.g. kangaroos Male kangaroos have boxing matches to see who gets the female. Natural selection favours strength and stamina of males that are able to fight off competitors.

4. Many males have strategies to prevent other males mating w the female while she is fertile5. Parthenogenesis – some populations don’t have males. Quite rare form of reproduction. Recent.

Less variation occurs in the population with this type so there are less chance individuals will have characteristics suited to a new env.

In short term organisms that reproduce maybe advantaged cos don’t need to waste resources to find a mate.

Long term the sexual ones are advantaged. Female lays fertile eggs that hatch (clones) Bynoes gecko are triploid – cell division results in eggs hatching while being fertilised – lower

diversity Spitfire wasps, aphids

3.2.7 Describe the conditions under which asexual reproduction is advantageous, with reference to specific Australian examples

if env. is stable asex repro allows a rapid colonisation to occur if env. conditions change many die offspring are identical – no diversity

corals – Ag and Horticulture works on this premise sexual repro allows for much variation and the ability to sustain the species if env. Changes its only through variation that natural selection and evolution can take place Sphagnum moss are spungy mounds that hold vast amounts of water and reproduce asex.

3.3.1 Analyse information from secondary sources to tabulate the differences that distinguish the processes of mitosis and meiosis

3.3.2 Identify data sources, gather, process and analyse information from secondary sources and use available evidence to discuss the relative success of internal and external fertilisation in relation to the colonisation of terrestrial and aquatic environments

3.3.3 Plan, choose equipment or resources and perform a first-hand investigation to gather and present information about flowers of native species of angiosperms to identify features that may be adaptations for wind and insect/bird/mammal pollination

4. A study of palaeontology and past environments increases our understanding of the possible future range of plants and animals

4.2.1 Explain the importance of the study of past environments in predicting the impact of human activity in present environments

when we look at past env.s we can gain an understanding of how certain orgs responded when certain conditions prevailed which allows us to make predictions about the future

As changes occur in env. (in studies of past) e.g. from cool and wet to being dryer and hotter, the distribution and abundance of species also changed.

Human activities are changing in the environment at a more rapid rate e.g. clearing forests for agriculture and timber also burning fossil fuels increases green house gases so therefore changes overall climate pattern in short space of time. Humans have big impact on future biodiversity.

4.2.2 Identify the ways in which palaeontology assists understanding of the factors that may determine distribution of flora and fauna in present and future environments

Palaeontology has helped us develop a picture of distribution and changes in past life forms in aus. palaeontology enables us to determine abundance and distribution of flora and fauna in the future If we can see how these factors (higher CO2/O2 concentrations, drier/wetter conditions, hotter/cooler temps)

affected orgs in the past we can make predictions about the futureo Enables educated decisions about env.

Other factors include soil types, changes in sea level, impact of humans (frequency/intensity of fires) global warming.

4.2.3 Explain the need to maintain biodiversity Biodiversity: refers to variety of life forms on this planet- its plants, animals, microbes and fungi, the genes

they contain and the ecosystems at which they are part. Also describes the diversity of organisms within a particular area or range.

all orgs rely on other life forms for their survival organisms using O2 rely on plants food comes from plants, animals and fungi as orgs go extinct it harms others’ chances of survival Habitat degradation e.g. land clearing and introduction of foreign species (foxes, rabbits, cane toads and

sparrows) are main causes for losses of biodiversity. World ag. Trade depends on biodiversity New varieties of livestock and crops are continually being bred with input from wild cousins. E.g. another

variety of wheat. This combats pests and diseases, increase drought resistance, boost nutrient content and increase crop yields.

Aus is one of 12 mega diverse countries and only developed one. biodiversity needs to be maintained to assist the survival of all orgs Selective breeding/in breeding= no good for biodiversity. Important to preserve seeds (seed banks) of all varieties to ensure genetic info is not lost

4.3.1 Gather, process and analyse information from secondary sources and use available evidence to propose reasons for the evolution, survival and extinction of species, with references to specific Australian examples

Kangaroos, wallabies and eucalyptus have evolved adaptations to survive in dried env. they can cope with heat, lack of water and bushfires and still cope.

4.3.2 Process information to discuss a current effort to monitor biodiversity A current biodiversity project has shown that it can help establish benchmarks against which future

changes can be referenced. Monitoring biodiversity can also assist in planning and management decisions so that conservation of some species is more likely. E.g. dessert knowledge CRC monitors dispersal and biodiversity impacts of buffel grass. Buffel grass is no good for native vegetation.