Teacher background information
Year 10 Science Content Description
Chemical sciencesDifferent types of chemical reactions are used to produce a range of products and can occur at different rates (ACSSU187 - Scootle )
investigating some of the chemical reactions and methods employed by Aboriginal and Torres Strait Islander Peoples to convert toxic plants into edible food products (OI.5)
This elaboration provides the opportunity to learn how Aboriginal Peoples of tropical north Queensland developed complex detoxification processes that allow the exploitation of plentiful food resources that were previously inedible. The various and sophisticated methods to remove toxins from poisonous endemic plants employed by many of Australia’s First Nation groups set the context for students to study the chemical reactions that underlie these processes and to investigate some of the factors that affect the rate of chemical reactions. At the same time, the exploration of these methods provides an opportunity to learn about the extensive scientific knowledge and highly developed inquiry skills of Aboriginal peoples in the detoxification of food products.
The development of complex detoxification processes by the rainforest Aboriginal peoples of North Queensland was undoubtedly driven by the food needs of the society at the time. The recognition of patterns in data, gathered from experiments that attempted to remove toxins, allowed this cultural group to modify and perfect the detoxification processes. Since Europeans survived a near-fatal experience after consuming under-processed cycad kernels on the first voyage to Australia by Cook and his party in 1770, many of the detoxification processes of poisonous plant foods employed by Aboriginal peoples throughout Australia have been documented. These detoxification processes provide evidence of Australia's First Nations peoples’ extensive scientific knowledge of chemical and physical processes, and an acute ability to draw conclusions that are consistent with evidence.
Students can explore a great variety of methods to remove toxins from poisonous foods as used by many of Australia’s First Nations’ peoples. A particularly suitable example for student investigation may be the method to detoxify cycad seeds employed by the rainforest Aboriginal people of North Queensland.
Cycads are a rich source of carbohydrates, but they contain a toxic substance called cycasin, which causes not only a range of acute symptoms, such as vomiting, nausea and abdominal pains, but also long-term damage to the nervous system and liver. Cycasin has been linked to various types of cancer. It consists of an innocuous sugar part (glucose) that is chemically bound to the active toxic substance methylazoxymethanol (MMA). In a chemical reaction with water (called hydrolysis), cycasin is broken up into these two parts, thus facilitating the removal of the toxic (and water soluble) MMA. However, this is a slow reaction under normal conditions, which made it necessary for the rainforest Aboriginal peoples of North Queensland to discover and employ a range of measures to speed up the reaction, including increasing both the contact surface with water and the temperature. In contrast, if the untreated cycad kernels are consumed, the same reaction happens at a much greater rate in the body due to the presence of a catalyst (an enzyme called β-glucosidase), thus leading to the rapid onset of acute symptoms.
By investigating the detoxification of cycads, students are given opportunities to gain a deeper understanding of the factors that govern the rate of chemical reactions, as well as to learn about and appreciate the highly developed science inquiry skills, ingenuity, and scientific knowledge of the rainforest Aboriginal peoples of North Queensland.
In the construction of this teacher background information, a list of consulted works has been generated. The consulted works are provided as evidence of the research undertaken to inform the development of the teacher background information. To access this information, please read and acknowledge the following important information:
Please note that some of the sources listed in the consulted works may contain material that is considered culturally offensive or inappropriate. The consulted works are not provided or recommended as classroom resources.
I have read and confirm my awareness that the consulted works may contain offensive material and are not provided or recommended by ACARA as classroom resources.
The following sources were consulted in the construction of this teacher background information. They are provided as evidence of the research undertaken to inform the development of the teacher background information. It is important that educators recognise that despite written records being incredibly useful, they can also be problematic as they are often based on non-Indigenous interpretations of observations and records of First Nations Peoples’ behaviours, actions, comments and traditions. Such interpretations privilege western paradigms of non-First Nations authors and include, at times, attitudes and language of the past. These sources often lack the viewpoints of the people they discuss and can contain ideas based on outdated scientific theories. Furthermore, although the sources are in the public domain, they may contain cultural breaches and cause offence to the Peoples concerned. With careful selection, evaluation and community consultation, the consulted works may provide teachers with further support and reference materials that could be culturally audited, refined and adapted to construct culturally appropriate teaching and learning materials. The ability to select and evaluate appropriate resources is an essential cultural capability skill for educators.
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Asmussen, B. (2008). Anything more than a picnic? Ceremonial Macrozamia feasting and mid-late Holocene socio-economic change in Australia. Archaeology in Oceania, 43(3), 93-103.
Asmussen, B. (2009). Another burning question: Hunter-gatherer exploitation of Macrozamia spp. Archaeology in Oceania, 43, 142-149.
Asmussen, B. (2010). In a nutshell: The identification and archaeological application of experimentally defined correlates of Macrozamia seed processing. Journal of Archaeological Science, 37(9), 2117-2125.
Asmussen, B. (2011). “There is likewise a nut...": A comparative ethnobotany of Aboriginal processing methods and consumption of Australian Bowenia, Cycas, Macrozamia and Lepidozamia species. Technical Reports of the Australian Museum, Online, 23 (Changing Perspectives in Australian Archaeology, Part X), 147-163.
Banks, J. S. (1950). Extract from the original manuscript journal written by Sir Joseph Banks on the "Endeavour", 1768-71: The voyage up the east coast of Australia and some accounts of New Holland. Sydney: Mitchell Library.
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Hegarty, M. P. (2001). Food safety of Australian plant bushfoods. Barton, ACT: Rural Industries Research and Development Corporation (Australia).
Horsfall, N. (1987a). Living in rainforest: The prehistoric occupation of North Queensland's humid tropics Vol. 1 (Doctor of Philosophy thesis). Queensland: James Cook University. Retrieved from http://eprints.jcu.edu.au/27492/
Horsfall, N. (1987b). Living in rainforest: The prehistoric occupation of North Queensland's humid tropics Vol. 2 (Doctor of Philosophy thesis). Queensland: James Cook University. Retrieved from http://eprints.jcu.edu.au/27492/
King, J. (1861). Alfred Howitt's diary: Narrative of John King survivor of the Burke & Wills expedition, September 1861 [Manuscript]. Victoria, Australia: State Library of Victoria.
Laqueur, G. L., & Spatz, M. (1968). Toxicology of Cycasin. Cancer Research, 28(11), 2262.
Martin, S. (1999). Plants before flowers: Focus on cycads. Tropical Topics: An interpretive newsletter for the tourism industry, (59), 1-8.
McKenzie, R. (1997). Australian native poisonous plants. Retrieved from http://anpsa.org.au/APOL7/sep97-4.html
Museum of Tropical Queensland. (2012, March 14). Aboriginal science tools: The Morah stone [Blog post]. The Queensland Museum Network Blog. Retrieved from https://blog.qm.qld.gov.au/2012/03/14/aboriginal-science-tools-the-morah-stone/
National Research Council (U.S.), U.S. National Committee for the International Union of Psychological Science. (1990). Cycads: Poisonous plants used for medicine and food. In R. Russell, P. Ebert Flattau, & A. Pope (Eds.), Behavioral Measures of Neurotoxicity: Report of a Symposium. Washington DC: National Academies Press. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK234978/#ddd00021
Pedley, H., & Jumbun Elders Reference Group. (1997). Aboriginal tools of the rainforest. Townsville: Jumbun & H. Pedley.
Pedley, H., & Queensland Department. of Education. (1992). Aboriginal life in the rainforest. Brisbane: Queensland Department of Education.
Wet Tropics Management Authority. (n.d.). Rainforest explorer: Bush tucker: Australia’s Tropical Rainforests. Retrieved from https://www.wettropics.gov.au/rainforest_explorer/Resources/Documents/factsheets/bushTuckerOfTheWetTropics.pdf
Woolston, F. P., & Queensland Department of Aboriginal and Islanders Advancement. Archaeology Branch. (1980). Some material culture of the north east Queensland aborigines. Archaeology papers (4), 1-9.