Alfred Wallace

Definition

Alfred Wallace was a British naturalist, explorer, and biogeographer known for independently proposing the theory of evolution through natural selection alongside Charles Darwin. His observations of species distributions in the Amazon and the Malay Archipelago led to important insights regarding biogeography and the concept of disjunct distributions, which refer to the presence of related species in geographically separated areas.

5 Must Know Facts For Your Next Test

1. Alfred Wallace's contributions to evolutionary theory were so significant that he is often referred to as the 'father of biogeography.'
2. He conducted extensive fieldwork in the Amazon rainforest and later in the Malay Archipelago, collecting specimens and documenting species that would inform his theories.
3. Wallace proposed the idea of 'disjunct distributions' after observing that similar species were found on islands that were geographically separated by water.
4. In 1858, Wallace sent a paper to Darwin outlining his ideas on natural selection, which prompted both men to present their findings jointly at the Linnean Society in London.
5. Wallace's work highlighted the importance of geographical barriers in species evolution, leading to a greater understanding of how isolation can drive diversification.

Review Questions

• How did Alfred Wallace's observations contribute to our understanding of disjunct distributions in biogeography?
  • Alfred Wallace's observations during his explorations in regions like the Amazon and the Malay Archipelago led him to recognize patterns where closely related species were found in isolated geographical areas. He noted that these disjunct distributions often arose due to historical factors such as climate changes or land barriers. This insight helped establish a connection between geographical features and biodiversity, highlighting how isolation can lead to unique evolutionary paths for species.
• Evaluate the impact of Alfred Wallace's theory of natural selection on the field of biogeography compared to Darwin's contributions.
  • Alfred Wallace's theory of natural selection complemented Charles Darwin's ideas but was also distinct due to its emphasis on biogeographical evidence. While Darwin focused on mechanisms within populations, Wallace provided critical insights on how geography influences species distribution and adaptation. Their combined work helped solidify natural selection as a foundational concept in evolutionary biology, making significant advancements in understanding the relationship between environment and organismal diversity.
• Synthesize Wallace's findings with modern biogeographical concepts to discuss their relevance in today's conservation efforts.
  • Wallace's findings about disjunct distributions are highly relevant today, especially concerning habitat fragmentation and biodiversity conservation. By understanding how geographical barriers affect species distribution and evolution, modern conservationists can devise strategies that address habitat connectivity and the preservation of critical ecosystems. Furthermore, recognizing that isolated populations may be more vulnerable to extinction reinforces the importance of protecting biodiversity hotspots identified through Wallace's principles, ensuring that conservation efforts are informed by historical biogeographical patterns.

Related terms

Biogeography: The study of the distribution of species and ecosystems across geographic space and through geological time.

Natural Selection:

The process by which organisms better adapted to their environment tend to survive and produce more offspring, a key mechanism of evolution.

Wallace Line:

A boundary line that separates the ecozones of Asia and Australia, illustrating distinct faunal distributions that reflect historical biogeographical events.