Birds and mammals are both warm-blooded animals with separate sexes determined by genetics, spinal cords, four-chambered hearts, four limbs and well-developed bony skeletons. Both groups include species that can fly and ... More »

Closely related organisms often share similar structures in their bodies, despite their different lifestyles. The simplest explanation for such similarities is that both species descended from a common ancestor with simi... More »

Echinoderms and chordates are related in the sense that they both belong to the deuterostome superphylum, exhibiting somewhat similar patterns of early development during the embryonic stage. The differences between the ... More »

Reptiles are cold-blooded vertebrates which generally have scales, four limbs with five toes each, and hearts with three or four chambers. Most also lay eggs with leathery shells, which are protected from dessication by ... More » Science Biology Zoology

Mammals and birds have four-chambered hearts. However, birds have much larger hearts in proportion to their size than mammals do, and their hearts pump more blood per minute than mammals of the same size. More »

South Korea is home to a wide variety of native mammals and birds. Some of these, such as the endangered baikal teal, live primarily in the local biome, while others, such as whales, only visit the waters near South Kore... More »

Animals that eat both plants and other animals, called omnivores, occur in every major animal lineage, including insects, fish, reptiles, mammals and birds. By contrast, some lineages, such as spiders, are completely dev... More »