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Ileum, caecum and colon of rabbit, showing Appendix vermiformis on fully functional caecum The human vermiform appendix on the vestigial caecum. The appendix was once believed to be a vestige of a redundant organ that in ancestral species had digestive functions, much as it still does in extant species in which intestinal flora hydrolyze cellulose and similar indigestible plant materials. [10]
Natural gills work because nearly all animals with gills are thermoconformers (cold-blooded), so they need much less oxygen than a thermoregulator (warm-blood) of the same size. [1] As a practical matter, it is unclear that a usable artificial gill could be created because of the large amount of oxygen a human would need extracted from the water.
The pseudobranch, also pseudobranchia, is the reduced first gill arch of a fish (on the inner surface of the opercle, near the junction of the preopercle) as well as a reduced "false" gill in some gastropods. In teleost fish, the pseudobranchs are mostly without respiratory function, and in elasmobranchs they are the gill arch of the spiracle.
Vestigial eye in the extant Rhineura floridana and remnant jugal in the extinct Rhineura hatchery (reclassified as Protorhineura hatcherii). [91] [92] Functionless wings in flightless birds such as ostriches, kiwis, cassowaries, and emus. [93] [94] The presence of the plica semilunaris in the human eye—a vestigial remnant of the nictitating ...
Artificial gills may refer to: Imitation gills put into stuffed fish for the sake of appearance in taxidermy; An inaccurate term for liquid breathing sets; Artificial gills (human), which extract oxygen from water to supply a human diver
Thus the zoologist Newman stated in the Scopes Trial: "There are, according to Wiedersheim, no less than 180 vestigial structures in the human body, sufficient to make of a man a veritable walking museum of antiquities." Some of the vestigial organs or organs containing evolutionary vestigial structures, as listed on the article about him: Adenoids
Pharyngeal clefts resembling gill slits are transiently present during the embryonic stages of tetrapod development. The presence of pharyngeal arches and clefts in the neck of the developing human embryo famously led Ernst Haeckel to postulate that " ontogeny recapitulates phylogeny "; this hypothesis, while false, contains elements of truth ...
Gastropods are capable of being either male or female, or hermaphrodites, and this makes their reproduction system stand out amongst many other invertebrates. Hermaphroditic gastropods possess both the egg and sperm gametes which gives them the opportunity to self-fertilize. [4] C. obtusus is a snail species of the Eastern Alps. In the ...