Wallace's Contributions and the Impact on Biology Revision Notes | GCSE OCR Foundation Biology

What this lesson covers

Investigate Alfred Wallace's worldwide evidence gathering, his work on warning colouration and speciation theory, and examine how evolutionary ideas tra...

• Explain Wallace's key contributions to evolutionary theory and speciation
• Describe how Wallace's work on warning colouration advanced biological understanding
• Evaluate the impact of Wallace's evidence-gathering on modern evolutionary theory
• Compare Wallace's original ideas with current understanding of speciation

Key ideas to keep in view

Use this lesson to stay inside B5.2 Natural selection and evolution while connecting the detail back to the wider B5: Genes, inheritance and selection topic.

• B5: Genes, inheritance and selection
• B5.2 Natural selection and evolution
• GCSE OCR Foundation Biology

Lesson notes preview

Read the core explanations from Wallace's Contributions and the Impact on Biology before testing yourself from memory.

• When you think of evolution, Darwin springs to mind. But there's another name that deserves equal recognition: Alfred Russel Wallace. This Victorian naturalist didn't just support Darwin's ideas — he developed the theory of evolution by natural selection independently, at the same time.
• Wallace spent years travelling the globe, from the Amazon rainforest to the islands of Southeast Asia. He wasn't just collecting specimens for museums. He was gathering evidence that would revolutionise how we understand life on Earth.
• His work didn't stop at evolution. Wallace made groundbreaking discoveries about how new species form and why some animals display bright warning colours. These insights still shape biology today.
• Bright colours or patterns displayed by animals to warn predators that they are dangerous, poisonous, or unpalatable. Used as a defence mechanism to avoid predation.
• Picture a poison dart frog — bright blue with black spots, impossible to miss. Most predators would think twice before attacking something so conspicuous. Wallace was the first to explain why.
• He realised that being brightly coloured isn't always a disadvantage. If you're toxic or dangerous, advertising this fact keeps you alive. Predators learn to associate bright colours with a bad experience and avoid similar prey in future.
• This was revolutionary thinking. Before Wallace, scientists assumed all prey animals should be camouflaged. He showed that sometimes, standing out is the best survival strategy.
• The evolutionary process by which populations evolve to become distinct species. Occurs when groups become reproductively isolated and diverge genetically over time.
• Wallace's second major contribution was his theory of speciation — how one species splits into two. He observed that closely related species often lived on different islands or were separated by geographical barriers.
• His key insight was that separation leads to divergence. When populations can't interbreed, they evolve independently. Over time, they become so different that even if they meet again, they can't produce fertile offspring.

Continue through the topic

Move to the related lessons or back to the topic page when you need the wider sequence before exam-style practice.