Two creatures that cannot interbreed, even if they resemble each other, must belong to different species. As is often the case in evolution, the rules of speciation are by no means ironclad.

When studying the Asian hornets’ (Vespa velutina) gut contents, a team of researchers from the University of Exeter in the United Kingdom, they found evidence of 1,400 different species ...

There are now at least 13 species of finches on the Galapagos Islands, each filling a different niche on different islands. All of them evolved from one ancestral species, which colonized the ...

The study revealed that green crabs from clam beds had significantly different diets compared to those from intertidal sloughs. A total of 54 unique species were identified from the stomach ...