Summary
Genome-wide analysis that identifies the loci and islands of divergence responsible for reproductive isolation.
In depth
Genome scans reveal 'islands of divergence' in otherwise similar genomes; gene flow may continue in other regions. Genes such as Hmr and Lhr in Drosophila cause hybrid incompatibility.
Chromosomal inversions can protect favoured combinations.
Genome scans show how divergence is spread: speciation with gene flow can produce islands of divergence, although later work found some peaks can be due to reduced diversity from selection in low-recombination regions (linked selection) rather than barrier loci. Inversions can protect sets of adaptation genes from recombination, as in sunflowers and in Heliconius butterflies, where wing pattern genes (optix, cortex) and mimicry supergenes are involved.
Examples of speciation genes include Prdm9 (hybrid sterility in mice), Odysseus in Drosophila and genes for mate choice in cichlids and Heliconius. Hybrid zones act as natural experiments, such as in crows and in house mice, and sequencing shows past introgression between species.
Frequently asked questions
What is Speciation Genomics?
Genome-wide analysis that identifies the loci and islands of divergence responsible for reproductive isolation.
Which area of biology covers Speciation Genomics, and how advanced is it?
Speciation Genomics is one of the 53 topics in Evolution. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Selective Sweeps, Reproductive Isolation, Allopatric Speciation.
Why does Speciation Genomics matter?
Genomes reveal that speciation is often a gradual, partly interbreeding process, and help us to find the genes that make species distinct.
Can you give an example of Speciation Genomics?
In Heliconius butterflies, wing pattern loci sit in divergent regions between species.
What should I learn before Speciation Genomics?
Work through the Beginner topics in Evolution first, such as Evolution, Natural Selection, Charles Darwin, then return to Speciation Genomics. Advanced topics assume the Intermediate vocabulary.
What topics are related to Speciation Genomics?
The closest topics to Speciation Genomics are Selective Sweeps, Reproductive Isolation, Allopatric Speciation, Species Concept. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Speciation Genomics?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Speciation Genomics. To practise the whole of Evolution, use the Evolution quiz.
How is Speciation Genomics different from Selective Sweeps?
Speciation Genomics: Genome-wide analysis that identifies the loci and islands of divergence responsible for reproductive isolation. Selective Sweeps: A beneficial allele rising to fixation reduces nearby genetic variation through hitchhiking. Read both side by side and note what each one explains.
How should I study Speciation Genomics step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Selective Sweeps and explain the difference aloud. Finally, take the Evolution quiz and come back to this page for any question you miss.