Year 8 Science · Unit 1 · Lesson 25
Challenge Worksheet
Learning Goals
Evaluate the claim
Someone claims...
"Extinction is a natural part of evolution, species have always gone extinct without human help. The Australian government spends billions of dollars trying to save individual species like the orange-bellied parrot, but there are only about 50 left in the wild. That money would do far more good if it was spent on hospitals and schools. We should accept natural extinction and move on."
(a) What part of this claim is supported by the science you have learned in this lesson? Identify at least one scientifically accurate element and explain it.
(b) What is misleading or scientifically incorrect in this claim? Identify at least two problems, one about the rate of extinction, and one about the value of biodiversity, and use evidence from the lesson to explain each problem.
(c) What evidence or extra information would strengthen or weaken this claim? Name two specific types of evidence, for example, data about extinction rates, economic valuations of ecosystem services, or effectiveness of conservation programs, and explain what each would show.
1. Australia is home to approximately 570,000 species, many of which are endemic. Using the concept of ecosystem services, construct an argument for why the loss of even one endemic species matters economically and ecologically, not just ethically. Refer to at least two specific ecosystem services in your answer.
2. The 2019–20 Black Summer bushfires killed an estimated 3 billion animals. Critically analyse: are bushfire-related extinctions "natural" events beyond human control, or are they a form of human-caused extinction? Use scientific reasoning about climate change, land management, and conservation responsibility in your answer.
Wrap Up
In one sentence, what was the main idea of this lesson?