Preliminary Bio Questions (1 Viewer)

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Identify data sources, gather and process secondary information for the following:

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

Ø Matching continental margins

Ø Position of mid ocean ridges

Ø Spreading zones between continental plates

Ø Fossils in common Gondwanan continents, including Glossopteris and gangamopteris flora, and marsupials

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Ø Similarities in present-day organisms on Gondwanan continents

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

· 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 become available.

Thanks.

 

[lyounamu]

Identify data sources, gather and process secondary information for the following:

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

Ø Matching continental margins

Ø Position of mid ocean ridges

Ø Spreading zones between continental plates

Ø Fossils in common Gondwanan continents, including Glossopteris and gangamopteris flora, and marsupials

Ø Similarities in present-day organisms on Gondwanan continents

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

· 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 become available.

Thanks.

1st one:

All landforms were originally joined together in a giant landmass called Pangaea
In the Jurassic, 160 million years ago, Pangaea split into two super continents: Gondwana and Laurasia
Gondwana: Australia, Africa, Madagascar, New Zealand, South America, India
Laurasia: Europe, North America, Asia (except India)
About 60 million years ago, Australia split from Gondwana
Evidence that Australia was once part of Gondwana:
§ Geological evidence:
- The rock strata around continental margins match exactly in many places, eg: 1) South Australia & Australia, 2) West Africa & east South America.
- Mid-ocean ridges are formed where plates are moving apart
- When plates move apart, molten rock rises up and forms new sea floor.
- In these areas, called spreading zones, the new rock that forms is older the further it is from the ridge
- This proves that the plates have been moving apart steadily for a long time
§ Biological evidence:
- The fossil record and present day organisms provide evidence that Australia was part of Gondwana
- Fossil Evidence:
o Glossopteris and Gangamopteris are fossil plants found in rocks of the same age in Australia, Africa, India, South America, Antarctica and New Zealand
o Fossils of marsupials have been found on all the continents that were part of Gondwana
o This is evidence that the continents were once joined
- Extant Organisms:
o Nothofagus, or the southern beech trees, are found in forests of Australia, New Guinea, New Zealand and South America
o Many plants and animals exist only where the Nothofagus still live; e.g. a parasitic fungus, a moss and bugs which depend on the moss
o Many groups of animals in Australia have close relatives in South America, Africa, India and New Zealand, but not in Northern Asia, Europe or North America
o These animals include: parrots, ratites (flightless birds), marsupial mammals, chelid turtles, some geckoes, many families of earthworms, terrestrial molluscs, spiders and insects, and the scorpion genus Cercophonius

 

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Thanks Namu .

 

[lyounamu]

2nd one:

Megafauna are not the ancestors of present animals, eg kangaroos didn’t come from giant kangaroos, rather they both evolved from a common ancestor.
Over the last 50k years most of the world’s megafauna have become extinct
Two theories have been put forward to explain this:
§ Climate Change: Megafauna were mainly suited to glacial conditions. Their large bodies enabled them to live in extreme conditions. In Eurasia and North America, when permafrost was replaced with forest, the megafauna died out and animals more adapted to forest began to thrive. In Australia, the temperature changed from cold-dry to warm-dry. As a result, water sources began to dry up, and many animals lost their habitat and died out.
§ Human Expansion: The time of the extinction of megafauna matches very closely the pattern of human migration into these areas. Megafauna are also large and slow, which makes them susceptible to hunting. In Africa, humans evolution occurred there, so hunting increased slowly, allowing animals to adjust. That is why there are still megafauna there. However, in places where humans arrived as skilled hunters, the most extinction occurred.
Living fossil (or relict species) are organisms that have changed little or not at all since ancient times.
Australia has many examples of living fossils, such as: 1) Stromatolites, 2) The Wollemi Pine, 3) Crocodiles, 4) Queensland lungfish, and 5) Monotremes.

 

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Thanks again Namu . That was quick.