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The Ensatina salamander has been extensively investigated because it is a ring species — a species that demonstrates how geography and the gradual accumulation of genetic differences factor into the process of speciation. Biologist Tom Devitt continues the more than 50 years of Ensatina research by applying new genetic techniques and asking new questions about this classic evolutionary example.
UC Museum of Paleontology
Correspondence to the Next Generation Science Standards is indicated in parentheses after each relevant concept. See our conceptual framework for details.
- Speciation is the splitting of one ancestral lineage into two or more descendent lineages.
- Speciation is often the result of geographic isolation.
- Speciation requires reproductive isolation.
- Occupying new environments can provide new selection pressures and new opportunities, leading to speciation.
- Scientific knowledge is open to question and revision as we come up with new ideas and discover new evidence.
- A hallmark of science is exposing ideas to testing.
- Scientists test their ideas using multiple lines of evidence.
- Scientists use multiple research methods (experiments, observational research, comparative research, and modeling) to collect data.
- The real process of science is complex, iterative, and can take many different paths.
- Science is a human endeavor.
- Scientists use multiple lines of evidence (including morphological, developmental, and molecular evidence) to infer the relatedness of taxa.
- Scientists use the geographic distribution of fossils and living things to learn about the history of life.
- Scientists use experimental evidence to study evolutionary processes.