Wallace worked worldwide gathering evidence for evolutionary theory.

The idea

Alfred Russel Wallace was a British naturalist who independently developed ideas about evolution by natural selection. Unlike Darwin, who largely worked from his Beagle collections and British observations, Wallace travelled extensively across South America and the Malay Archipelago, collecting thousands of specimens and recording where each was found. This worldwide fieldwork gave him evidence that species vary geographically and that similar species often live in neighbouring regions. For example, his observations of animals on separate islands helped him link variation, isolation and the formation of new species. His letters to Darwin prompted the joint presentation of their ideas in 1858.

What earns the marks

• Wallace travelled widely, including in South America and the Malay Archipelago, rather than working only in one country.
• He collected many specimens and recorded detailed information about where each organism was found.
• His worldwide observations showed that closely related species often occupy neighbouring geographical areas.
• He used patterns in variation and distribution to support the idea that species change over time.
• His evidence contributed to the development of evolutionary theory alongside Darwin's work.
• He recognised that geographical isolation could allow populations to diverge into new species.

Common mistakes and how to put them right

• Thinking Wallace worked only in Britain or only with fossils.

  Put it right: He gathered evidence through worldwide fieldwork on living organisms.

• Confusing Wallace with Lamarck or claiming Wallace invented natural selection alone.

  Put it right: Wallace independently reached similar conclusions to Darwin and they presented their ideas jointly.

• Assuming Wallace's evidence was purely theoretical with no specimens.

  Put it right: His conclusions were based on extensive collecting and recording of real organisms.

Exam tips

• Name specific regions such as South America or the Malay Archipelago to show precise knowledge rather than saying only that he travelled.
• Link Wallace's worldwide evidence to the idea that species vary and can change, rather than listing places without explanation.
• Use phrases such as gathered evidence and supported evolutionary theory to keep answers focused on the specification statement.