Tag Archives: species

Chapter 8: Classification

Linnaeus

Carl von Linne – Image Source

Learning Intention: To understand the biological system of classification and how living organisms are named and identified.

Success Criteria: Given sufficient information, you will be able to identify relationships between living organisms and classify them into their appropriate groups.

Carolus Linnaeus was a swedish botanist and zoologist who developed the system of classification that biologists still use today to order our natural world – “binomial nomenclature“. Just like large shops and warehouses that need to store huge numbers of items, biologists find it useful to classify organisms using a hierarchical system that groups the same kinds of organisms together. All living things are grouped and named using the following sytem:

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species

The latin binomial system uses the genus and species name as a universal, unique identifier for a particular type of organism. This minimises the problem of organims that might have different common names in different parts of the world (eg. Blackbird, brown snake) and uses a one language recognisable to scientists worldwide. If two particular organisms have the same genus name, they are more closely related than two that belong to the same family but belong to different genera. However, if two organisms have the same species name, but belong to a different genus, they may not be closely related at all. The species name is more of a descriptor, so, for example, Eucalyptus citriodora is the lemon-scented gum and Backhousia citriodora is the lemon myrtle. They belong to different genera, so are not as closely related as two eucalypts or two myrtles.

Fox control in Victoria

red fox

By Chris and Catherine

The Red Fox (Vulpes vulpes) is a pest which was introduced to Australia from Europe in 1855 for hunting purposes. Populations of foxes in the wild became established in 1870. It took less than 100 years for the foxes to spread across most parts of Australia.

The red fox has had a major, negative impact on Australia since its population increased to uncontrollable proportions. The Red Fox has played a major role in the decline of the population of ground-nesting birds, small mammals and reptiles. It is also thought to be the main cause of population decrease for many threatened species. The Red Fox also poses an economic threat to many farmers by preying on their vulnerable farm stock such as lambs and chooks. It is also a carrier of rabies, a disease which affects mostly dogs but can be passed on to humans, livestock and native mammals.

 The government has employed tactics such as bounties in order to reduce the population of the Red Fox. In 2002 the government introduced 24 collection points were people could hand in fox tails in order to receive a $10 reward. In the first year there was 150 822 fox tails handed in. The program was evaluated after the first year and found that the program was ineffective in reducing the fox numbers and so the program was scrapped in mid 2003.  

 The most effective methods of culling Red Foxes are…

  • Lethal baiting
  • Shooting
  • Trapping
  • Den fumigation
  • Den destruction

Exclusion fencing is another effective strategy but it is extremely expensive and un-suitable for farmers.

Darwin’s 200th Birthday

Image Source – The United Kingdom 10 pound note.

This year many scientists are celebrating Charles Darwin’s 200th birthday. Darwin is famous for his book, “The Origin of Species” which was a revolution in biology and controversial in it’s day for the theory that species could evolve over generations to form new species – and that humans had evolved from an ape-like ancestor! Darwin was the first scientist to propose this theory and provide a simple mechanism – survival of the ‘fittest’  – that could explain how it works. Even before chromosomes and genetics had been discovered, he proposed that there was some ‘hereditary factor’ that was passed through generations and conferred characteristics that made individual organisms more or less likely to survive, breed and pass on those characteristics to their offspring.

Catalyst is celebrating Darwin’s 200th birthday with a special edition, that includes interviews with famous scientists, articles about DNA and missing fossil links and archives of related stories. Read a biography of Charles Darwin from the BBC and find out more at “Darwin – the Genius of Evolution“.