Speciation
The formation of new species. In allopatric speciation, a physical barrier splits a population and the groups evolve apart. In sympatric speciation, new species form in the same area. Reproductive isolation keeps them separate.
Last updated
Analogy
A road splitting a village in two so that two dialects form.
In practice
Finches on different Galapagos islands evolved different beak shapes and became separate species.
Practice
Flashcards
- What is allopatric speciation?Speciation after a physical barrier splits a population.
Questions people ask
Why do biologists use more than one definition of a species?
A common definition is a group of organisms that can interbreed and produce fertile offspring. It does not work for organisms that reproduce asexually, or for fossils. Biologists therefore also use other definitions, based on shared ancestry, appearance or DNA, depending on the situation.
What are reproductive barriers?
Reproductive barriers stop different species interbreeding. Prezygotic barriers act before fertilisation, such as different mating seasons, courtship songs, or incompatible gametes. Postzygotic barriers act after, such as hybrids that are infertile, like a mule, which comes from a horse and a donkey.