Figuring out what species are is not as easy as one might think. Find out how biologists define species and how new species evolve.
This article is located within Evolution 101.
UC Museum of Paleontology
Student learning on this topic may be enhanced by class discussion.
Correspondence to the Next Generation Science Standards is indicated in parentheses after each relevant concept. See our conceptual framework for details.
- Present-day species evolved from earlier species; the relatedness of organisms is the result of common ancestry. (LS4.A)
- Speciation is the splitting of one ancestral lineage into two or more descendent lineages.
- Speciation requires reproductive isolation.
- Occupying new environments can provide new selection pressures and new opportunities, leading to speciation. (LS4.C)
- Our understanding of life through time is based upon multiple lines of evidence.
- Scientists use experimental evidence to study evolutionary processes.
- Speciation is often the result of geographic isolation.