Animals are primarily classified according to morphological and developmental characteristics, such as a body plan. One of the most prominent features of the body plan of true animals is that they are...Animals are primarily classified according to morphological and developmental characteristics, such as a body plan. One of the most prominent features of the body plan of true animals is that they are morphologically symmetrical. This means that their distribution of body parts is balanced along an axis. Additional characteristics include the number of tissue layers formed during development, the presence or absence of an internal body cavity, and other features of embryological development, suc
This page discusses the similarities in vertebrate embryonic development, particularly during the pharyngula stage, where key structures appear. It introduces the recapitulation theory, which posits t...This page discusses the similarities in vertebrate embryonic development, particularly during the pharyngula stage, where key structures appear. It introduces the recapitulation theory, which posits that early developmental stages mirror ancestral forms, despite variations among species. The page notes that while embryos exhibit analogous features like limb bud formation, many are lost or altered later.
