Support materials only that illustrate some possible contexts for exploring Science as a Human Endeavour concepts in relation to Science Understanding content.
Theories of the origin of living organisms from inanimate materials (abiogenesis) in a ‘primordial soup’ were first published in the 1920s, but received little attention. However in the 1950s, experimentation by Urey and Miller indicated that by introducing a spark to an aqueous mixture of compounds likely to have been present on early Earth, organic molecules could form. This is an example of how scientists can theorise about the early conditions on Earth that may have led to the origin of life and then use an experimental design as a ‘proof of concept’ (ACSES013). A wide range of other evidence supports the theory of abiogenesis, however many people also reject this theory in favour of a religious view of creation (ACSES011).
Analysis of past mass extinction events, based on evidence in sedimentary rocks and the fossil record, identifies the cause of these events as physical change. Current data on global species loss indicates that a ‘sixth extinction’ of greater severity than previous events may be imminent. Research indicates that this extinction will be caused by biotic rather than physical events, including human transformation of the landscape, overharvesting of species, pollution and introduction of alien species. The fossil record provides evidence for significant ecosystem change and loss of species associated with human activity. Contemporary evidence of human population increase, increase in land clearing, pollution and alien species introduction is theorised to align with evidence of species loss around the globe (ACSES013). Actions to halt the loss of species require social, economic and cultural support and a commitment to global action for sustainability (ACSES014).
The fossil record and sedimentary rock evidence, in addition to the oral histories and art sites of Aboriginal and Torres Strait Islander peoples, suggest that Australia’s environments have changed in significant ways since it separated from Antarctica approximately 45 million years ago, including becoming much drier (ACSES009). Evidence indicates that the landscape changed from cool temperate rainforest to deserts, open grasslands and open forests over the last few million years, and that fire stick farming played a significant role in the last 50 000 years. Some aspects of Australia’s past are debated, including the relationship between the extinction of the megafauna and hunting by Aboriginal people. However there is a wide body of evidence that suggests climate change was more likely to have been the cause of megafauna extinction than overhunting (ACSES013).