Curated OER
AP: Chapter 24: The Origin of Species
AP biology buffs define vocabulary terms and answer critical-thinking questions about evolutionary trends. They compare macroevolution to microevolution, differentiate ploidy possibilities, explain isolation barriers, and more....
Curated OER
Evolution in a Ring
Young scholars discuss a definition for ring species. They compare the concept of ring species to natural selection and examine the role of geography and climate in species formation.
Encyclopedia of Earth
Encyclopedia of Earth: Biodiversity: Species
Defines the term species and the origin of the concept. Provides estimates of numbers of species in different biological categories, explains what endangered species are, and what ring species are. (Published: May 26, 2010)
American Institute of Biological Sciences
Action Bioscience: Ring Species: Unusual Demonstrations of Speciation
Ring species are a part of the speciation process which helps to understand evolution. Discover what we have to learn from ring species in this article.
Other
The Evidence for Evolution
These pages are part of a site called "Evolution," that accompanies a textbook by the same name. Mark Ridley is the author, and in this section he discusses the evidence for evolution.
Other
Evidence for Evolution: Formation of New Species
These pages are part of a site called Evolution that accompanies a textbook by the same name. Mark Ridley is the author. These pages offer an explanation of speciation using reproductive isolation and differences in phenotype.