Question

what sequence of events resulted in this Australia having animals and plants that are different from those found anywhere else?

Answer 1

Australia’s climate is geographically very variable compared to other countries, resulting in ecosystems ranging from deserts to tropical rainforests. Whilst some parts of Australia have extremely low average rainfall, such as Alice Springs (around 270 millimetres per year), other parts of the continent have very high average rainfall, such as the town of Tully in north Queensland (more than 4000 millimetres per year). This variability in climatic zones in Australia has resulted in a particularly diverse range of species, with each climatic zone having its own uniquely adapted flora and fauna.

The age of Australia’s landscape also means it generally has very poor soils with low nutrient levels. Many of Australia’s plants and animals have adapted to these low-nutrient soils over millions of years. Australia’s acacias have evolved means of capturing nitrogen in poor soils, while banksias have evolved to survive in low phosphorous soils. The Central and Eastern Avon Wheatbelt of south-west Western Australia (a National Biodiversity Hotspot (End note 2)) is an example of the high levels of species endemism (not found anywhere else) that have resulted from adaptation to low-nutrient soils. It has been identified as a national hotspot of biodiversity for its richness in endemic plants including grevilleas, hakeas, eucalypts, acacias, eriostemons, and the asteracea family.