Sibling species
Sibling species are species which look alike, but cannot breed with each other.[1][2][3]
The classic case is Drosophila pseudoobscura and D. persimilis. They are almost identical, but if flies from one species are put with flies from the other species, they do not interbreed. Another example was the European mosquito known as Anopheles maculipennis. This turned out to be a cluster of six different species, some of which transmit malaria, and some do not.[2]
Sibling Species Media
The butterfly genus Heliconius contains some species that are extremely difficult to tell apart.
The rubyspot damselfly Hetaerina americana is suspected to be a cryptic complex with at least one other species of rubyspot.
A species complex typically forms a monophyletic group that has diversified rather recently, as is shown by the short branches between the species A–E (blue box) in this phylogenetic tree.
Possible processes explaining similarity of species in a species complex:a – morphological stasisb – hybrid speciation
The Anopheles gambiae mosquito complex contains both species that are a vector for malaria and species that are not.
