Los metazoarios
Metazoans include everything from sponges and jellyfish to insects and vertebrates . Metazoos incluyen todo, desde las esponjas y las medusas ainsectos y vertebrados . It is used to be thought that sponges evolved from a different single celled organism to higher animals, so that the the Metazoa were considered to be a polyphyletic taxon. Es loque se pensaba que las esponjas evolucionaron a partir de otro organismo unicelular a los animales superiores, por lo que el Metazoa fueron considerados como un taxón polifilético. But recentmolecular phylogenetic evidence indicates this is not the case. Pero los últimos datos filogenéticos moleculares indica que este no es el caso. The metazoans are considered to be monophyletic, all of themhaving evolved from a single unicellular choanoflagellate ancestor, sometime during the Ediacaran period . Los metazoos se consideran monofilético, todos ellos han evolucionado de un ancestro unicelularcoanoflagelado solo, en algún momento durante el periodo Ediacárico .
A metazoan has a body composed of eukaryotic cells that are differentiated into tissues, organs, and usually a digestive...
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