Evolution and Biogeography of Australian Fauna

Question 1

does australia have many endemic species?

Answer 1

yes

Question 2

insects with southern connections

Answer 2

350 mya
insects with Gondwana elements: dragonflies, stoneflies, termites, bugs and beetles, scorpion flies, flies, cadis flies, moths, butterflies, wasps, bees, ants and sawflies
coevolution of insects and plants

Question 3

when did frogs and mammals evolve?

Answer 3

around the Gondwana breakup (mesozoic)

biogeographic patterns are not confused - cannot travel over water

Question 4

adaptive radiation of frogs

Answer 4

Anura order (frogs and toads) are the only amphibians in Australia
myobactrachids and hylids (largest Australian frog groups) - Gondwana families that adapted to radiated to dry conditions - burrowing, less time as eggs and tadpoles
gastric breeding frogs
pouched frogs house tadpoles in pouches for protection
microhylidae and ranidae are asian origin (through PNG)

Question 5

australian reptiles

Answer 5

some dinosaurs (bipedal plant eaters from cretaceous) but all went extinct 
NZ tuatara are an ancient group 
side necked tortoises are Gondwana 
snakes and lizards are from Asia 
gekkos are asian and Gondwana

Question 6

introduced species

Answer 6

dingo (7000 ya by indigenous people) and European species 200 ya

Question 7

three classes or mammals

Answer 7

prototheria (egg laying monotremes), metatheria (marsupials) and eutheria (placental mammals)

Question 8

prototheria

Answer 8

platypus and echidnas

• endemic to australia (old fossils in South A)
• primitive features- egg laying, secreting milk from glands not nipples, cloaca, reptilian bones
• 120 mya

Question 9

metatheria

Answer 9

marsupials

• fossils in N and S America
• Dasyuromorphia and Peramelemorphia - polyprotodont; carnivores and omnivores with more than one pair of incisors in the lower jaw (Tasmanian devil)
• Diprotodontia - mostly herbivores with one pair of incisors on the lower jaw - wombat
• notoryctemorphia - marsupial moles

Question 10

eutheria

Answer 10

bats and rats

• rodents radiated over a relatively short amount pf time after dispersal from the north (arrive in Pliocene from Asia)
• bat fossils from Eocene

Question 11

Pangean

Answer 11

inhabited austrália since Pangea formed (300mya) and when it split 230mya - tuatara

Question 12

Gondwanan

Answer 12

since Gondwana was joined (India and Antarctica too)

• ASAA - Australia, South America, Africa (kiwi, frogs, ratite like emus and ostriches)
• ASA - Australia and South America (split 60mya) wombat and wallaby

Question 13

old immigrants

Answer 13

flew or rafted to Australia from SE Asia when Australia was an island (60-5mya)
- some bats

Question 14

new endemic

Answer 14

arrived from Asia (SE) when Australia was closer (5mya)

- rodents

Question 15

human introduced

Answer 15

deliberately or accidentally brought (500ya, particularly in last 200)

Question 16

ways plants avoid being eaten

Answer 16

• change when and where they produce flowers and leaves - harder for herbivores to specialise
• poisonous leaves - terpenes (flammable in eucalypts) and cyanides
• tannins bind to proteins and make them hard to extract
• physical barriers such as spines, thick cell walls and silica

Question 17

eucalyptus new after fire and old leaves

Answer 17

more protein in new leaves
cell wall is more easily broken in young leaves
phenolics are higher in young leaves - chemical defence

Question 18

koala teeth

Answer 18

grind up leaves and break open cells

teeth wear over the years (lower faster) - spend more time eating when old, chew twice as much and starve

Question 19

kangaroos are macropods

Answer 19

rat kangaroo, potoroos and bettongs

• roots, seeds, fruits, fungi, invertebrates
• adaptation: potoroos and bettongs indirectly digest fungi with bacteria
• patchy distribution

Question 20

dorcopsis, tree kangaroos, wallabies, pademelon and quokka

Answer 20

• low fibre plants
• adaptation: foregut fermenters - microbes ferment vegetation and produce nutrients
  distribution: wet areas

Question 21

rock wallabies and kangaroos

Answer 21

grass, shrubs, bark and fallen leaves

• adaptation: foregut fermentation and adapted grazing teeth for cropping and grinding
• wide distribution - woodland, rocky outcrops and islands

Question 22

red kangaroos and nail-tail wallabies

Answer 22

grass
adaptation: grazing teeth and foregut fermentation
dry areas

Question 23

evolution of diets

Answer 23

earliest were probably omnivores
began browsing leaves etc. - evolved cutting teeth and foregut fermentation
began to eat grasses as well as Australia became more open