Question

what do you understand by sibling species

Answer 1

sibling species :Any of two or more related species that are morphologically nearly identical but are incapable of producing fertile hybrids. Sibling species can only be identified by genetic, biochemical, behavioral, or ecological factors, and are thought to have become divergent very recently.

Answer 2

Sibling species are very similar in appearance, behaviour and other characteristics but they are reproductively isolated. In other words, sibling species are pairs or groups of genetically closely related species which are often morphologically indistinguishable, but are reproductively isolated, meaning that while they may interbreed, the offspring cannot reproduce.

(also called clone )