Year 10 Science · Unit 1 · Lesson 6
Challenge Worksheet
Learning Goals
Find the mistake
A student wrote this answer
"Selective breeding and natural selection are fundamentally the same process, both produce evolution by changing the allele frequencies in a population over time. The only difference is that selective breeding happens faster because humans are involved. Both processes are driven by the same force: survival of the fittest. Selective breeding essentially speeds up what nature would have done anyway, so calling it 'artificial' is misleading."
(a) Identify at least two specific scientific mistakes or oversimplifications in the student's answer. Be precise about what is wrong in each case.
(b) Write a corrected version of the student's answer. Your version should accurately describe how selective breeding and natural selection are similar AND different, covering: (i) who or what acts as the selecting agent; (ii) the direction of change; and (iii) whether "survival of the fittest" applies to both.
(c) Explain why this kind of mistake, conflating selective breeding with natural selection, is easy for students to make. What conceptual confusion typically leads to this error?
1. Dogs were domesticated from wolves approximately 15,000 years ago. Today over 400 recognised breeds exist, ranging from Chihuahuas (2 kg) to Saint Bernards (90 kg). Using the concept of selective breeding, explain how such extreme variation could arise in one species within a relatively short evolutionary timescale. Why would this rate of change be impossible through natural selection alone?
2. Selective breeding produces organisms optimised for human needs but not necessarily for survival in the wild. Give a specific example of a selectively bred organism that would struggle to survive without human care, and explain why the traits selected by humans are actually disadvantageous in a natural environment.
Wrap Up
In one sentence, what was the main idea of this lesson?