metameriás

Metamerism is a biological concept describing the division of an animal's body into a series of linearly arranged, repeated parts called metameres. This segmentation is most evident in the external appearance and internal anatomy of certain animal phyla. The process by which this segmentation occurs is known as metameric segmentation.

Phyla exhibiting metamerism include the Annelida (segmented worms), Arthropoda (insects, spiders, crustaceans), and Chordata (which includes vertebrates, though segmentation is often more obscure in adults). Each metamere, or segment, can contain repeated internal organs and structures, reflecting a body plan that is built up from a series of similar units. This modular construction can allow for specialization of different body regions. For example, in arthropods, segments may be modified for locomotion, sensing, or reproduction.

The evolutionary advantage of metamerism is thought to lie in its contribution to efficient locomotion and the potential for increased complexity through the duplication and subsequent differentiation of body units. The development of metameres is controlled by complex genetic mechanisms during embryonic development, ensuring the precise arrangement and repetition of body parts.