vestigial organs

For centuries, researchers knew that Euglenids, a diversified family of aquatic unicellular organisms, could reshape their bodies in any number of elegant ways but no one knew why they did it. Some researchers think they now know: “Amongst biophysicists, metaboly was thought to be a way to swim in a fluid, where these cells live,” Arroyo said. “However, protistologists are not convinced by this function for metaboly, since Euglena can swim very fast beating their flagellum, as do many other cell types. Instead, the predominant view is that metaboly [body deformations] is a functionless vestige ‘inherited’ from ancestors that used cell body deformations to engulf large prey. Watching cells executing such a beautiful and coordinated dance, we did not believe Read More ›

From ScienceDaily: Although it is widely viewed as a vestigial organ with little known function, recent research suggests that the appendix may serve an important purpose. In particular, it may serve as a reservoir for beneficial gut bacteria. Several other mammal species also have an appendix, and studying how it evolved and functions in these species may shed light on this mysterious organ in humans. Heather F. Smith, Ph.D., Associate Professor, Midwestern University Arizona College of Osteopathic Medicine, is currently studying the evolution of the appendix across mammals. Dr. Smith’s international research team gathered data on the presence or absence of the appendix and other gastrointestinal and environmental traits for 533 mammal species. They mapped the data onto a phylogeny Read More ›

Has recently retired from being “vestige of evolution” … From Jordan Rosenfeld at Mental Floss: While the appendix is not required for digestive functions in humans, Belz tells mental_floss, “It does house symbiotic bacteria proposed by Randal Bollinger and Bill Parker at Duke University to be important for overall gut health, but particularly when we get a gut infection resulting in diarrhea.” Infections of this kind clear the gut not only of fluids and nutrients but also good bacteria. Their research suggests that those ILCs [innate lymphoid cells] housed in the appendix may be there as a reserve to repopulate the gut with good bacteria after a gut infection. ILCs are hardier than other immune cells, and thus vital to Read More ›

So says some new research. First, remember “vestigial organs”? We learned in high school that  vestigial organs, including the appendix, show that there is no design in nature. Being teens, we never considered the implications of the fact that the proposition is never supposed to work the other way. That is, now that almost all such organs have been found to be functional (so far), the no-design PR lobby just moved to other claims. For example, junk DNA! Oh wait, let’s check our notes here on junk DNA… whoops… Okay, and now the humble appendix has the floor: Immune cells make appendix ‘silent hero’ of digestive health “Popular belief tells us the appendix is a liability,” she said. “Its removal is one Read More ›