September 2010 was a week on Vertebrate Zoology Evolution. Understanding the evolution of vertebrates pre-fish to amphibians, reptiles and ultimately mammals is fascinating. We studied Australia's Monotremes and Marsupials and the way our unique climate progressed their evolution.
Of the Australian marsupials its fascinating to know that when Australia broke off from Gondwana around 55 million years ago, they were mostly tree dwelling animals similar to possums. They jumped from branch to branch in search of food and kept out of the way of dangerous mega fauna. Later as the Australian climate changed and became drier, vast grasslands grew in place of the cool temperate rainforests, still found in Tasmania. With the disappearance of mega fauna and huge grass plains kangaroos developed their hind legs to bound the distances in search of food. The kangaroo pouch also developed to ensure that their young joey's would not bounce out and be lost, and a special teet developed in the pouch that locked the joey on.
Obviously this evolution occurred over 10's of millions of years, without the recent devastation to the environment caused by humans. Land clearing for development and agriculture , weed invasion and river quality have reduced habitat for many species, although the roo still has a niche in some areas.
There should be no delay in rehabilitating and caring for our ecology. Call Robert Griffith @ ESD Landscape Contractors Pty Ltd on 61 2 9986 1741 for all the help you need.
It was fascinating to identify how our earliest pre-vertebrate relatives were star fish or the echinoderms. You may not know but the common sea squirts on the rocks at the beach, (the tunicates) have very similar internal systems to us humans, with nerves, stomach and a pharynx.
By far the greatest evolutionary change was the advent of the jaw in fish. From here, animals were able to prey on food, protect themselves and manipulate their environment. Most other evolutionary advances were to serve the new competitive advantage the jawed vertebrates had gained.
To understand each of the animals UNE has a comprehensive museum. Students have to dissect a range of vertebrates to analyse hearts, livers, lungs, bone structures etc. We learnt to identify most of the common Australian native animals by counting the various types of teeth in their skulls.
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| Platypus skeleton |
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| UNE has all the equipment for good scientific research |
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| The two rats on the left are the common pest rat (Rattus rattus), on the right are our native rats , notice the native rats tail is shorter than its body. |
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| The large male Kangaroo skin in the foreground has a skin some 25mm thick around the belly, where they kick each other to determine who will be the dominant male. |
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| The hind legs of the kangaroo provide an almost effortless mode of transport on the vast grassland plains of Australia. |
