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Postoji li naziv za evolucijski gubitak vestigijalnih struktura?

Postoji li naziv za evolucijski gubitak vestigijalnih struktura?


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Razmotrimo biološku strukturu koja više nema koristi za organizam, poput očiju organizma čija populacija sada živi u potpunom mraku. Mogu se sjetiti tri razloga zašto bi takva struktura mogla nestati:

0) Slučajne promjene strukture tijekom vremena ne bi bile ispravljene odabirom koji bi favorizirao funkcionalnu verziju strukture, što bi dovelo do šire varijacije u kojoj većina verzija strukture više ne djeluje učinkovito.

1) Resursi koje struktura zahtijeva mogli bi se bolje utrošiti na strukture koje se stvarno koriste; npr. ljudskim očima potrebno je mnogo krvi koja bi se mogla upotrijebiti drugdje.

2) Možda postojanje vrlo složene strukture dovodi do bioloških problema koji više ne bi bili problem da struktura nije prisutna; npr. ljudske grudi i hormoni dojke često dovode do raka.

Jesu li ova tri primjera razumna sredstva pomoću kojih bi značajka nestala? Postoje li drugi mogući razlozi?

Postoji li opći naziv za fenomen evolucijskog uklanjanja tragova zbog toga što te značajke više nisu korisne za populaciju?


Ovaj fenomen može se (i opisan je) opisati kao regresivna evolucija (gubitak fenotipske osobine). Postoji nekoliko razloga zašto se to događa:

  • Neutralne mutacije koje se fiksiraju genetskim zanosom.
  • Pozitivan odabir regresivnih mutacija koje su korisne.
  • Pleiotropni antagonizam: pozitivna selekcija za jednu osobinu može imati za posljedicu narušavanje druge osobine za koju nije jako odabran.

Primjer degeneracije oka koji ste odabrali dobar je jer je dobro proučen kod špiljske ribe (koja je nastala iz vidljive površinske ribe i ima degenerirane oči). Normalni razvoj oka je pod kontrolom transkripcijskog faktora Pax6. Ekspresija drugog transkripcijskog faktora, Shh, smanjuje ekspresiju Pax6. Shh ekspresija duž embrionalne srednje linije odgovorna je za obostrano cijepanje očnog polja. Prekomjerna ekspresija Shh u površinskoj ribi dovodi do degeneracije oka i doista je otkriveno da špiljske ribe imaju prošireni obrazac Shh izražavanja.

Pećine su također doživjele promjenu ponašanja na hranjenje na dnu i postale su manje agresivne da se više usredotoče na pronalaženje hrane. Kako se to događa, prošireni Shh izraz također uzrokuje proširenje čeljusti i pojačavanje okusnih pupoljaka, a oba pomažu u hvatanju i uzorkovanju riječnog dna. Nadalje, povećana ekspresija Shh tijekom razvoja mozga utječe na smanjenje agresivnosti i prelazak na hranjenje.

Ovo je primjer pleiotropnog antagonizma: pozitivna selekcija za poboljšanja čeljusti i promjene ponašanja putem proširenog Shh izraza, koji povećavaju sposobnost u špiljskim okruženjima, može objasniti zašto je oko degeneriralo.


Takozvane "zaostale" značajke definirane su na post-hoc način kao značajke koje nemaju pozitivnu korelaciju s sposobnošću stanovništva u trenutnim životnim uvjetima. Ne postoje posebni nazivi evolucijskih procesa koji dovode do njihovog gubitka, budući da se radi o potpuno istim evolucijskim procesima koji djeluju na bilo koju značajku koja ima neutralan/negativan učinak na kondiciju.


Biologija II

10 komentara:

Riječ vestigial potječe od koncepta tragičnosti koji se odnosi na genetski određene strukture ili atribute koji su očito izgubili većinu ili cijelu svoju predačku funkciju u datoj vrsti. Vestigijalne strukture uglavnom se odnose na organ koji je bio koristan u evolucijskoj prošlosti životinja.
Vestigijalne strukture smatraju se dokazima evolucije jer prikazuju ostatke strukture koja je nekad imala primjenu u podrijetlu organizma. Vestigijalne strukture postale su prvo nepotrebne zbog promjena u okolišu i s vremenom su se povukle u populacijama do te mjere da postaju nefunkcionalne. Ove strukture na bilo koji način nemaju utjecaja na organizme pa nema potrebe za evolucijom da ih se riješi.

Jedan primjer vestigijalnih struktura mogao bi biti mišić plantaris, koji je dug i čvrst mišić na ljudskom stopalu i teletu koji više nema značajnu svrhu. Ovaj se mišić nekad koristio za pružanje proprioceptivnih povratnih informacija središnjem živčanom sustavu u vezi s položajem stopala, ali nema važnu funkciju, a liječnici ga redovito uklanjaju kako bi ga uzeli za rekonstruktivnu kirurgiju srca. Uklanjanjem ovoga nema gubitka funkcije pri hodanju ili ravnoteži.

Drugi primjer mogao bi biti ljudski slijepo crijevo koje danas nema funkciju, ali se vjeruje da je u ranijim organizmima pomoglo u razgradnji hrane poput biljaka.

Konačno, posljednji primjer mogli bi biti udovi i zdjelice zmija, koji sugerira da su njihovi preci u jednom trenutku morali imati noge, ali su tijekom evolucije postali samo još jedna tragična funkcija i nemaju funkciju u modernim zmijama. Međutim, to ih ni na koji način ne narušava pa se zdjelične kosti neprestano prenose na sljedeće generacije.

Miller, B. (2005, 02 09). 10 najboljih beskorisnih udova (i drugih tragova organa). Preuzeto sa http://www.livescience.com/11317-top-10-useless-limbs-vestigial-organs.html

Scoville, H. (2013). Vestigijalne strukture kod ljudi. Preuzeto sa http://evolution.about.com/od/evidence/tp/Vestigial-Structures-In-Humans.htm

Abedon, S. (n.d.). Vestigijalna struktura. Preuzeto sa http://www.biologyaspoetry.com/terms/vestigial_structure.html

Vestigijalne strukture jedan su od najvećih dokaza da je evolucijska teorija točna. Vestigijalno doslovno znači kada se misli na organ koji je degeneriran, rudimentaran ili atrofiran, koji je tijekom evolucije postao nefunkcionalan (Novi Oxfordski rječnik). Dakle, ostaci strukture su dijelovi našeg tijela koji ostaju tamo, ali se više ne koriste i ostaju kao dokaz kako smo se razvili i prestali ih koristiti.

Neki daždevnjaci koji žive u špiljama i dalje imaju oči iako je vrsta slijepa, pa bi to bila ruševna građevina. http://bioweb.cs.earlham.edu/9-12/evolution/HTML/live.html

Slijepo crijevo je još jedna tragična struktura, izvedeno je iz većeg caceuma koji je organ koji ima bakterije i pomaže biljojedima da probave hranu. http://www.talkorigins.org/faqs/vestiges/appendix.html

Dlake na tijelu također su ružičasta struktura i iako su njihovi dijelovi korisni poput obrva kako bi slatkiši bili podalje od naših očiju, većina ih je beskorisna jer ne ovisimo o dlakama na tijelu koje nas grije http: //science.howstuffworks. com/life/human-biology/vestigial-organ1.htm

Vestigijalne strukture su oznake koje pokazuju da smo s vremenom doista evoluirali. Kako je definirano u oxfordskom rječniku, riječ ostatak znači: (ili se odnosi na organ ili dio tijela) degeneriran, rudimentaran ili atrofiran, postajući nefunkcionalan tijekom evolucije. Prva poznata riječ bila je 1880.-1885., Kada je izvedena iz latinske riječi vestigium što znači trag ili korak. Nadalje, ruševna struktura više nije potreban dio tijela koji služi kao oznaka ili trag za prikaz našeg podrijetla.
Zubi mudrosti, koji su ljudski treći skup kutnjaka, a posljednji izlaze iz zubnog mesa, ostaci su strukture. Najčešća je pretpostavka da je ljudska mandibula bila veća i da je stoga zahtijevala više zubi. Kako se ljudska lubanja smanjivala, kutnjaci su ostali. U životu ovog zajedničkog assentera umnjaci su trebali žvakati i gnječiti biljke. Trenutno se u našim tijelima većina umnjaka mora kirurški ukloniti zbog straha od infekcije i udara, a to je nedostatak prostora u čeljusti. Johnson, dr. George B. & quotDevidens for Evolution & quot. 8. lipnja 2006
Plica luminaris je mali dio tkiva s unutarnje strane oka koji je ružičast. Smatra se da je ovo ruševna struktura ostaci opne koja stvara nit, neka vrsta kapka trećeg oka koji se kreće oko oka kako bi ga navlažio ili zaštitio od opasnosti. Iako mnoge životinje još uvijek imaju potpuno funkcionalne membrane sa nititacijom, ljudi imaju samo plica luminaris koja nema nikakvu svrhu. Vestigijalne strukture kod ljudi // & quot Evolucija - prirodni odabir, // Povijest života na Zemlji, darvinizam ,.
Maslačak ima prašnike i tučke koji se u većini biljaka koriste za spolno razmnožavanje s drugim biljkama. U slučaju maslačka, umjesto da koristi ove organe, maslačak koristi aseksualnu reprodukciju, stoga u osnovi stvara klon sebe. U prošlosti se maslačak vjerojatno razmnožavao nespolno i s vremenom je postao samodostatan. Posljedično tome, prašnici i tučci u maslačku ostaci su strukture jer više ne služe maslačku u korisne svrhe.
& quotVestigial Structures. & quot Objavljeno: 30.1.2011
http://www.livescience.com/11317-top-10-useless-limbs-vestigial-organs.html
Izvori
.
http://darwinsdarlings.blogspot.com/2013/02/vestigial-structures-by-alia-bhimji.html
http://en.wikipedia.org/wiki/Human_vestigiality#cite_note-18
http://www.livescience.com/11317-top-10-useless-limbs-vestigial-organs.html
http://gartlerwritingstudio.blogspot.com/2013/05/vestigial-organs.html

Vestigijalne strukture su dijelovi organizma koji su naizgled izgubili sve ili većinu svojih funkcija za tu vrstu. Znanje o postojanju spomenutih nefunkcionalnih dijelova sudjeluje od davnina, budući da je njihovo postojanje bilo mnogo prije evolucije darvinizma, ali ovaj put je dalo široko prihvaćeno objašnjenje. Čak je i Aristotel raspravljao o neobičnom postojanju tragova očiju madeža u svojoj knjizi “History of Animals ”.
Izraz Vestigial structure potječe od … Charles Darwin objasnio je kako su vestigijalne strukture tragovi prošlih razdoblja, pa su ti beskorisni dijelovi vrsta fosila iz onoga kako su naši preci izgledali i koji su im dijelovi tijela potrebni za preživljavanje rudimentarni dijelovi način su na koji možemo saznati kakav je nekada bio život i koliko smo mi i druge vrste došle do com.
Mogli bismo reći da postoje tri vrste vestigijalnih značajki, a to su: one koje su opstale s ovim statusom kroz dugogodišnja istraživanja, poput trtice (repna kost) ili umnjaka (krajnici), zatim postoje prolazni embrionalni organi, koji polako blijede zbog nedostatka svrhe, poput embrionalnog repa i konačno postoje strukture pogrešno identificirane kao ostaci, poput endokrinih žlijezda.
Najpoznatije vestigijalne strukture kod ljudi su krajnici, slijepo crijevo i umnjaci. Iako za njima nemamo istu potrebu kao za homolognim organima, oni imaju svoje donekle “funkcije ” ili jesu. Znanstvenici vjeruju da su raniji oblici ljudskih bića imali krajnike kako bi jeli određenu hranu koja im je na raspolaganju. Dr. Maeda i Mogi su napisali da krajnik funkcionira i u proizvodnji antitijela i u stanično posredovanom imunitetu. [Maeda] Drugi suradnici ovog dodatka rekli su da je krajnik važan kao limfoidni organ u gornjim dišnim putovima. Slijepo crijevo drži bakterije “crijeva#, što je vrlo korisno, no redovito se može zaraziti i ubiti ako pukne.
Što se tiče dokaza da imamo neke gene zajedničke sa životinjama, jedna bi tragična funkcija bila naježanje, postoji vrlo mali mišić u podnožju svakog folikula dlake koji će se skupiti i povući kosu prema gore, a za pticu ili pas, koji bi mu mogao pomoći da dobije veličinu i držanje kako bi uplašio grabežljivce i zadržao više zraka kako bi mogao ostati topao, ali i mi ih imamo.


Kreacionistička objašnjenja za ostatke struktura

Imao sam malu raspravu s ovim kreacionistom na Quori, koji je bio moderator (ili barem jedan od njih) tamošnjeg & quotMutation/Creation & quot. Smiješno je kako je pokušao objasniti ostatke strukture, ali ja##277 imam problema s odgovaranjem na neke od njih. Evo njegovih objašnjenja, a on je izjavio & quotreal science & quot razotkrivena tragična uvjerenja davno:

& quotVestigial je vjerska riječ. Vjera u ostatke organa dovela je do raznih jadnih zaključaka koje je znanost kasnije odbacila. Krila koja više ne funkcioniraju, ili kornjaši bez krila. Gubitak strukture i funkcije suprotan je smjer od onog koji darvinizam zahtijeva. (Da, zajedničko podrijetlo zahtijeva smjer), To je u skladu s biblijskim modelom stvaranja.

* Muške bradavice razvijaju se kao rezultat spolne diferencijacije. To nema veze sa zajedničkim porijeklom.

* Ljudska repna kost / trtica jednostavno je krajnja kost naše repne kosti. To nema veze sa zajedničkim porijeklom. Trtica je zamišljena kao mjesto za sidrenje nekoliko mišića koji pomažu u držanju naših organa na mjestu i pomažu nam da sjedimo uspravno i obavljamo nuždu.

* Naježanje na ljudima nema nikakve veze s dlakavim precima. Gusje su dio našeg sustava borbe ili bijega. Također, & quot čak i s malom količinom dlake koju imamo, kad stane na kraj, pomaže u očuvanju tjelesne topline hvatajući više zraka. Također, mišići povezani s naježanjem kože istiskuju ulje na kožu, a dlačice sprječavaju začepljenje uljnih žlijezda. Štoviše, mišićne kontrakcije stvaraju toplinu, od koje se više može stvoriti drhtanjem. & Quot

Također je tvrdio da su naše oči savršene takve kakve jesu, stoga su dizajnirane: & quotObrnuta mrežnica daleko je superiorniji dizajn od svih organizama koji je imaju. (Orlovi i ljudi imali bi velikih problema s rasporedom mrežnice glavonožaca).

Rekao je i ovo: Upotrebljavate evolucionistički argument prošlosti za koji je znanost prije više od 20 godina dokazala laž. Još u prošlom stoljeću evolucionisti, poput Richarda Dawkinsa, koristili su obrnutu mrežnicu kao dokaz protiv tvorca. Nije znao za dizajn optičkih vlakana.

Upravo sam mu odgovorio da, iako bi neke ruševne strukture mogle još imati koristi, poanta je u tome da su izgubile svoju izvornu funkciju.

Vestigial je vjerska riječ. Vjera u ostatke organa dovela je do raznih jadnih zaključaka koje je znanost kasnije odbacila. Krila koja više ne funkcioniraju, ili kornjaši bez krila

Ne, to je opažanje, predviđanje evolucije koje je potvrđeno.

Gubitak strukture i funkcije suprotan je smjer od onog koji darvinizam zahtijeva. (Da, zajedničko porijeklo zahtijeva smjer),

Ovo je samo očito lažno.

U skladu je s biblijskim modelom stvaranja.

Čekaj, mislio sam da je upravo rekao da ostaci strukture ne postoje. Sada oni postoje i podržavaju kreacionizam? Odluči se. Kreacionisti nikada nisu predvidjeli da ćemo pronaći tragove struktura, to su učinili biolozi.

Muške bradavice razvijaju se kao rezultat spolne diferencijacije. To nema veze sa zajedničkim porijeklom.

To je beskorisna, ponekad štetna struktura koja je posljedica neučinkovitog, rasipničkog razvojnog sustava. Je li riječ o vestigijalnoj strukturi ili spandrelu, semantička je razlika.

Ljudska repna kost / trtica jednostavno je krajnja kost naše repne kosti.

Ovo čak nema ni smisla. Repna kost je kraj repne kosti? Što?

Trtica je zamišljena kao mjesto za sidrenje nekoliko mišića koji pomažu u držanju naših organa na mjestu i pomažu nam da sjedimo uspravno i obavljamo nuždu.

To je krhak, nepotrebno kompliciran način za to, jer se temelji na spojenim segmentima repa.

Gusje su dio našeg sustava borbe ili bijega.

Točno, ali potpuno beskoristan dio jer, za razliku od životinja s više dlake, ne čine da izgledamo veće. To je doslovno cijela poanta.

Čak i s malom količinom kose koju imamo, kad stane na kraj, pomaže u očuvanju tjelesne topline hvatajući više zraka

Gluposti. Samo ih pogledajte. Ne mogu 't i don 't.

Također, mišići povezani s naježanjem kože istiskuju ulje na kožu, a dlačice sprječavaju začepljenje uljnih žlijezda.

Čak i da je to istina, za to ne moraju stvarati gadnu kožu.

Štoviše, mišićne kontrakcije stvaraju toplinu, od koje se više može stvoriti drhtanjem.

Dakle suvišni su. Drhtavica čini istu stvar bolje. Hvala vam što ste dokazali naše mišljenje.

Obrnuta mrežnica daleko je superiorniji dizajn od svih organizama koji je imaju. (Orlovi i ljudi imali bi velikih problema s rasporedom mrežnice glavonožaca).

Primjećujem da se ne trudi potkrijepiti ovo. Svaka kreacionistička tvrdnja koju sam o tome vidio završava lažnim predviđanjima kad ih gurnete dovoljno daleko, poput one da bi dubokomorske ribe trebale imati mrežnice poput glavonožaca (nemaju 't).

Upotrebljavate evolucionistički argument prošlosti za koji je znanost prije više od 20 godina dokazala laž.

Ne, stvarni stručnjaci to još uvijek dobro razumiju na području užasnog dizajna.

Nije znao za dizajn optičkih vlakana.

Dizajn & quot optičkih vlakana & quot rješenje je koje ga čini nešto manje loše. Da imamo sustav glavonožaca, za početak bi nam trebala#kvotoptička vlakna, koja pokrivaju samo mali dio retine, a i dalje iskrivljuju i prigušuju svjetlost.

Izvrsni kontrapunkti. Možete li preporučiti neku knjigu o evoluciji? Biologiju sam zadnji put imao u srednjoj školi i tamo sam pohađao samo prvi tečaj (imali su dva). Prošlo je 7-8 godina, pa sam malo zahrđao što se tiče biologije općenito. Čitao sam o 2/3 Sebični gen sad, trebam li nastaviti Prošireni fenotip poslije? Nisam čitao 't Zašto je evolucija istinita ipak, pretpostavljam da je to dobro polazište?

Vjera u ostatke organa dovela je do raznih jadnih zaključaka koje je znanost kasnije odbacila.

UVIJEK provjerite kreacioniste. Zato jednostavno pitajte: & quotkoje je ružne zaključke nauka oborila kad i od koga & quot. & quotIzvori molim & quot. Savjet: ne dopustite prebacivanje ciljeva i druge preusmjeravanja. U takvim situacijama uvijek inzistiram postavljajući pitanje: "Koji, kada, od koga, izvori molim".

Najvjerojatnije će cijela rasprava biti gotova. Jedini oskudni izvori do kojih će doći bit će kreacionistički članci. Ali to se ne računa jer nisu znanstveni.

Jedini znanstveni izvori do kojih bi na kraju mogao doći su uvijek o pronalaženju neke funkcije vestigijalnog organa ili funkcije. Na primjer: ljudsko slijepo crijevo igra ulogu u imunološkom sustavu. Ovo je zabluda slamača jer iskrivljuje definiciju tragičnosti.

Darwin je o ostacima (koje je nazvao & quotrudimentary & quot) pisao u Podrijetlo vrsta:

Orgulje koje služe u dvije svrhe mogu postati rudimentarne ili potpuno pobačene za jednu, čak i važniju svrhu, a za drugu ostati savršeno učinkovite.

Od tada se nije mnogo promijenilo.

Dakle, ljudsko slijepo crijevo uistinu ima slab doprinos imunološkom sustavu (nitko tko je izgubio slijepo crijevo zbog njegovog kirurškog uklanjanja nikada nije imao vidljivih problema s borbom protiv infekcija više nego kad je još imao organ), ali to uopće nije važno, njezina tragičnost proizlazi iz činjenice da više ne radi & quotapendix & quot stvari - što je: probavljanje celuloze.

Zato pokušajte izbjeći ulazak u tu zamku.

Osobno ne bih nazvao muške bradavice primjerom tragičnosti jer ih je teško razlikovati od spolne diferencijacije tijekom embrionalne gestacije. Nije prikladno za komunikaciju s kreacionistima koji glupe i koji se obično vole švrljati unatrag.

Kao i obično, kreacionisti VOLE izostaviti ogromne dijelove promatračkih dokaza. Laganje i zavaravanje njihova je druga priroda. Dokazi su izostavljeni: rep kralježnjaka lako se i nepogrešivo identificira među kopnenim životinjama. To je produžetak leđne moždine rastom dodatnih kralježaka iza anusa zatvorenih prilično tipičnim tkivima poput sekundarne živčane cijevi (leđne moždine), nohorda, mezenhima i repnog crijeva.

Na kraju Carnegie faze 15 ljudskom embriju izrastao je rep koji se proteže izvan anusa, što čini oko 10-20% ukupne duljine embrija. Ne pokazuje razlike s anatomijom i fiziologijom repa životinja i sastoji se od 10-12 repnih kralježaka u razvoju. Ovdje su slike ljudskog embrija na Carnegiejevoj 15. fazi.

Nakon Carnegiejeve 15. faze, šesti do dvanaesti kralježak postupno nestaje zbog fagocitoze - bijela krvna zrnca razgrađuju tkivo, kao i druga tkiva koja ih zatvaraju. Ovaj proces završava u novorođenčadi s izvornim repom svedenim na malu kost sastavljenu od četiri spojena kralješka lijevo (trtica) koji ne vire sa stražnje strane, kod nekih ljudi čak opremljeni pričvršćenim "mišićima repa" - koji ipak ne mogu pomaknite ga (ti su mišići također sami po sebi ostaci).

Ovaj tijek izrastanja tkiva u embrionalnoj gestaciji koji na kraju nazaduje i ostavlja novorođenčetu samo tragove ostataka, ono što je nekad započelo u potpunosti, ima smisla u svjetlu evolucije. Evolucija podrazumijeva da neki organi ili anatomske ili fiziološke strukture mogu zastarjeti zbog promjena u životnim uvjetima koje izaziva okolina u kojoj živi vrsta. Kada se to dogodi, DNK mutacije koje utječu na ovu osobinu više nisu pod selektivnim pritiskom. Osobina koja je zastarjela ne treba se održavati. Tako štetne mutacije postupno počinju utjecati na osobinu. Osobina obično zahtijeva kaskadu gena za uredan rad. Mutacije koje pogađaju DNA na tim mjestima onemogućit će jedan od koraka u kaskadi nasumično. Ostali koraci i dalje mogu uspjeti. To je razlog zašto ljudski embriji počinju razvijati repove, ali je proces u nekoj fazi prekinut jer jedan bitan korak više nije funkcionirao.

Gubitak strukture i funkcije suprotan je smjer od onog koji darvinizam zahtijeva.

Ovo je zabluda slamarice. Kao što sam rekao: laganje i zavaravanje druga je priroda kreacionista. Gubitak strukture i funkcije je CENTRALNI RAZVOJ teorije evolucije i njome je izravno predviđen. Evolucija je to gotovo neizbježan evolucijski fenomen.

Gubitak strukture i funkcije suprotan je smjer od onog koji darvinizam zahtijeva. . U skladu je s biblijskim modelom stvaranja.

Kada pokušate pomiriti mitologiju kasnog brončanog doba sa znanstvenom stvarnošću 21. stoljeća, neizbježno ćete pasti u kontradikciju. Ovo je lijep primjer: prvo poricanje tragičnosti ne postoji, a zatim odjednom postavljeno da je u skladu s stvaranjem. Pravo.

Dakle, u jednom retku teksta imamo slamaricu i oksinoron.

Richard Dawkins upotrijebio je obrnutu mrežnicu kao dokaz protiv tvorca. Nije znao za dizajn optičkih vlakana.

Čudno jer u svim svojim izlaganjima o lošem dizajnu oka kralježnjaka opširno spominje dizajn optičkih vlakana.

Kao što sam rekao: laganje i zavaravanje druga je priroda kreacionista.

Nekako mi pobježe i zašto se ovaj primjer pojavljuje u diskursu o tragičnosti.

Krila koja više ne funkcioniraju, ili kornjaši bez krila.

Nitko nije tvrdio da su krila nefunkcionalna. Ovdje opet vidimo slamača iskrivljujući definiciju vestigijalnosti kao jednaku nefunkcionalnosti. Nije bilo 't i nije 't. Nijedan ɾvolutionnist ' nikada nije izjavio da su krila nefunkcionalna. Sve knjige iz biologije napisali su ɾvolucionisti ' i opširno opisuju funkcije krila (prikaz, održavanje ravnoteže tijekom trčanja, komunikaciju).

Vrlo dobri bodovi. Budući da dokazi ne podržavaju njihove kreacionističke stavove, oni moraju iskriviti dokaze. To i laganje, rudarenje citata itd. Trebao bih se kloniti Quore, pretpostavljam da toliko kreacionista tu izbacuje gluposti.

Tamo se s njima teže raspravljati jer iznose svoje & citate & quot svjedočanstvom. ne čini uopće uvjerljivim one koji znaju svoje stvari, ali mnogi će vjerojatno pasti na njihovu retoriku.

Srećom, većina YEC -a prevladava samo u SAD -u, ali povremeno sam ga vidio i ovdje u Europi. Nadajmo se da se neće širiti. Ako jest, to je#zabrinjavajuće.

Pogledajte neke kreacionističke odgovore na Quori, frustrirajuće je pročitati koliko gluposti mogu izbaciti.

Je li uopće predstavio neke izvore?

Ne, nije 't. Ne bih se trebao čuditi, kreacionisti se nikada ne mogu pozivati ​​na recenzirane znanstvene radove koji podržavaju njihovo gledište.

Iako se u drugom pitanju o Quori, on ipak pozvao na neke izvore, od kojih su dva kreacija.com i evoluisamyth.com. potpuno nema pristranosti u tim izvorima.

Upravo sam mu odgovorio da, iako bi neke ruševne strukture mogle još imati koristi, poanta je u tome da su izgubile svoju izvornu funkciju.

Točno. Naš dodatak ne radi ono što radi kod drugih vrsta - djeluje kao komora za fermentaciju za probavu žilavih tvari. Bakterije još uvijek žive tamo - to je uvijek bio slučaj za taj odjeljak. No probava se tu više ne javlja. Vestigial.

Također, sugerira li ova osoba da su mužjaci razvili bradavice neovisno o ženama?

Također, sugerira li ova osoba da su mužjaci razvili bradavice neovisno o ženama?

To je bio i moj stav o tome, iako je često teško razumjeti što kreacionisti misle (jednako često daju nejasne izjave koje se mogu tumačiti na različite načine, što može otežati suprotstavljanje onome što govore). Kreacionisti mentalne gimnastike kroz koje prolaze su smiješni.

Bi li to ostao vestigalni organ ako bi se prešlo na prehranu koja se sastojala isključivo od tvrdog biljnog materijala?

Bio sam zbunjen i oko muške bradavice. Sigurno možda "loš dizajn" ako ne učine puno, ali pružaju dodatnu osjetljivost i možda se pobrinu da muškarci mogu dobiti i rak dojke. Ljudi ih ponekad navode kao loš dizajn, ali ne bih ih nazvao tragovima iako ne (obično) pružaju pristupnu točku za hranjenje beba, ali na neki način mi smo ih naslijedili, a oni to zapravo ne čine mnogo.

Zvuče kao uobičajeni argumenti. & quotBog je upravo tako uspio & quot, & quotthe fall & quot, & quotit 's all just broken gene & quot, & quotvestigial znači beskorisno & quot itd.

Zanima me zašto se čini da je Quora takav magnet za ove stvari? Je li to samo šačica korisnika koji puno objavljuju ili postoji samo hrpa kreacionista? Pretpostavljam da vaše odgovore dobiva na vrhu Google pretraživanja, što je vjerojatno dobar način za promicanje publiciteta.

I ja sam se pitao isto: Zašto su kreacionisti toliko zastupljeni u Quori? Tamo ih doista ima jako puno. Pretpostavljam da to ima veze s načinom na koji tamo prikazuju odgovore (a također i s onim što ste spomenuli o tome da odgovori idu na vrh Google pretraživanja).

Mogao bih ga pozvati na raspravu ovdje na Redditu, ali svaki put kad sam zamolio kreacionistu da dođe ovamo, nađu neki izgovor da se ne pridruže.

Mislim da bih istaknuo neke dokaze iz embriologije. Na primjer, ljudi razvijaju rep, koji se na kraju apsorbira (to je poput četiri ili pet kralježaka). Također razvijamo punu dlaku koja također nestaje. Mi smo placentalni sisavci, ali se uz bok razvijamo žumanjčana vreća.

Postoji i smiješno tortourus put grkljanskog živca. Ima smisla u ribama, a ne u primatima. Ljudski genom sadrži mnogo pseudogena. To su geni s invaliditetom koji više ne kodiraju proteine. Na primjer, naš genom sadrži gen za kodiranje žumanjka.

Da. Kako to da nikad ne promatramo organe prije postoje? s/

Nije uspio iznijeti sve gene koji su ostaci i mnoge primjere u embriologiji koji pokazuju da su oni tragovi. Iste strukture napravljene od istih bjelančevina izgrađenih od istih gena odgovorne su za ptice koje razvijaju zube dinosaura, ljudi za rast trećeg niza kapaka, ptice i majmuni u razvoju više dugih repova u razvoju (prvo stil koji dijelimo s ribama prije nego što ptice razviju dinosaura repovi i majmuni razvijaju repove sisavaca prije nego što im se smanji duljina i spoje i imobiliziraju). S vremena na vrijeme deaktivirani geni ne funkcioniraju i te se značajke nastavljaju razvijati tako da majmuni imaju repove, ljudski mužjaci imaju kosti penisa, ptice imaju zube, kitovi imaju analne peraje, a kitovi u bijeloj boji imaju zube kao atavizam. Kad se u potpunosti ne formiraju, očito im je smanjena funkcija ako uopće postoje u odrasloj dobi. Najbolje objašnjenje za te zajedničke gene čak i kod organizama kojima nedostaje funkcija je zajedničko nasljeđivanje.

Muške bradavice mogu biti i "ostaci", ali manje jer s ženskim hormonima mogu rasti grudi i proizvoditi mlijeko baš kao i trudnice ili nedavno trudne ženke. Obično ne rade ništa osim pružaju dodatnu osjetljivost u prsnom području. Naježanje kože isto kao i male strukture mišićnog tipa u koži uzrokuju da nam kosa stane ravno na kožu, ali nemamo dovoljno debele folikule dlake niti dovoljno dugu dlaku na tijelu da bismo izgledali veće ili pružili neku dodatnu toplinu. Ovo ima više smisla ako su naši preci imali malo više krzna - i na temelju genetike Jesu.

Užasno je neuko ili nepošteno od njega govoriti bilo što što je rekao. "Bolji" dizajn koji ima slijepu točku u našem vidnom polju u organima koji se prvenstveno koriste za vid? Sigurno da bi privlačenje više svjetla moglo učiniti stvari svjetlijima i fizički bolnima za gledanje, ali da se naši treći kapci i dalje pomiču, pružili bi dodatnu zaštitu od svjetla i prašine. Ali kako stoji, naši veliki obrubi majmunskih obrva s našim čupavim obrvama mi limenka žmiriti kako bi se prilagodio i ne treba zadržati funkcionalnost predaka. Tako evolucija ne biti usmjeren ima najviše smisla.

Potpuno si proturječi izjavljujući da bi evolucija trebala biti vođen proces prema "evolucionistima", a zatim spominje sve oblike dokaza koje smo iznijeli kako bismo dokazali da nije. Kao što bi nas vođena evolucija lako mogla natjerati da postignemo najbolje moguće rezultate na temelju prijašnjih uvjeta poput respiracije ptica, perja i optičkih živaca orijentiranih na glavonošce umjesto našeg manje učinkovitog disanja kontroliranog dvosmjernom membranom, kose i slijepih mrlja. Zato što mi nemojte imaju sve te stvari unatoč tome što su započeli isto kao i organizmi koji su s njima završili prije više od 700 milijuna godina, to je jasan dokaz da populacije opstaju unatoč genetskoj raznolikosti unatoč tragovima gena unatoč očito "lošem" dizajnu. Možemo graditi samo od onoga što nasljeđujemo, ali slomljenost je dobar znak da nas nitko ne tjera da postanemo određeni način. Nitko nas ne čini takvima kakvi smo na kraju postali a da se ne oslanjamo ni na evolucijske procese.

Još samo jedan primjer izobličenih dezinformacija koje pokušavaju podržati lažno uvjerenje krivim predstavljanjem samo jedne moguće alternative, a zapravo nikada ne uzimaju u obzir što se zapravo događa (treća opcija).


UVOD

A fundamental step in the life cycle of any virus is encapsidation of the viral genome within a protein shell, or capsid, which protects the genome from environmental assault as the virus transits between hosts. There are two basic strategies that viruses use for genome packaging. In one strategy, the genome first condenses, typically via interaction with virally encoded positively charged proteins. The virus capsid then assembles around the condensed genome. This strategy is used by many enveloped RNA viruses such as alpha viruses and flaviruses. In a second strategy, an empty virus shell is first assembled, and the genome is then actively packaged into this pre-formed container. This is the strategy used by some double-stranded (ds) RNA ( 1) and single-stranded (ss) DNA viruses ( 2, 3) and virtually all dsDNA viruses such as herpes virus, pox virus, adenovirus and all the tailed dsDNA bacteriophages ( 4). This second strategy is remarkable considering the enthalpic, entropic and DNA bending energies that must be overcome to package DNA to near crystalline densities within the confined space of the capsid.

The molecular motors that power genome encapsidation are some of the most powerful molecular motors in nature, capable of producing forces in excess of 50 piconewtons ( 5). To provide a frame of reference, ∼5 pN are necessary to break a hydrogen bond, and ∼200 pN are required to break a weak covalent bond. For comparison, myosin and kinesin each operate at ∼5–10 pN ( 6, 7). Thus, viral dsDNA packaging motors operate at high forces, as they must to overcome the ∼20 atm of pressure estimated to be present within fully packaged capsids. The energy for packaging is provided by a virus-encoded ATPase that converts the chemical energy of ATP hydrolysis into the mechanical translocation of DNA. These ATPases belong to a large ancient family of ring ATPases involved in various polymer movement/manipulation tasks such as cell division, protein degradation, chromosome segregation, DNA recombination, strand separation and conjugation. Hence, the operation of viral DNA packaging ATPases may also reflect the mechanistic principles of a broad class of molecular motors responsible for basic macromolecular partitioning processes.

Further, successful DNA packaging requires that motors carry out several related yet functionally distinct tasks. During initiation, the packaging motor must self-assemble at a unique vertex of the capsid and recognize its own DNA amongst the multitude of other DNAs present in the cell. During translocation, the motor must coordinate the activities of multiple components to efficiently translocate DNA. During termination, the motor transitions from a translocation-mode to a termination-mode, wherein the highly pressurized DNA is retained in the head, and the motor disengages to initiate packaging on another empty procapsid. Thus, dsDNA viruses must execute a complex sequence of carefully orchestrated molecular tasks to successfully encapsidate their genomes. While each of these tasks have been examined individually to varying extents, very little is known regarding how dsDNA packaging motors transition between them.

Bacteriophage phi29 has long served as a model system for investigating genome packaging, and a highly efficient in vitro phi29 DNA packaging system has been developed that has allowed packaging to be interrogated via multiple experimental approaches ( 4, 8, 9). Genetic, biochemical, and structural studies indicate that the motor is comprised of three macromolecular components (Figure 1A) ( 4, 10): (i) a dodecameric portal, or connector protein (gene product 10 (gp10)) ( 11) (ii) a pentameric ring of a phage encoded structural RNA molecule (pRNA) ( 11–15) and (iii) a pentameric P-loop ASCE ATPase ring (gene product 16 (gp16)), analogous to the large terminases in other phage systems, and which provides the energy for packaging ( 10, 11, 16). These three components are arranged as three co-axial rings, and the dsDNA genome is translocated into the phage capsid through a continuous channel along their common central axis (Figure 1A). Note that unlike other bacteriophages that produce a concatemeric genome, polymerases from phi29-like phages use a protein-priming mechanism to produce a unit-length genome capped at both 5′-ends ( 17). Hence, phi29-like phages would not seem to need the additional nucleolytic machinery that is present in other phages, and which is used to cut the concatenated genome at the beginning and end of packaging.

Packaging Motor of the Bacteriophage phi29. (A) A cryoEM reconstruction of the phi29 ATPase motor complex attached to the procapsid ( 24) (EMDB: EMD-6560). The connector, pRNA, CTD, NTD and dsDNA are colored red, yellow, cyan, magenta and green, respectively. (B) Schematic model of a single dwell-burst packaging event in the mechanochemical cycle of the phi29 packaging motor. During the dwell phase (green line), the ATPase motor is charged with ATP. During the subsequent burst phase (blue line) hydrolysis of the ATP results in the translocation of 10 bp of dsDNA in four 2.5 bp sub-steps associated with four hydrolysis events ( 21).

Packaging Motor of the Bacteriophage phi29. (A) A cryoEM reconstruction of the phi29 ATPase motor complex attached to the procapsid ( 24) (EMDB: EMD-6560). The connector, pRNA, CTD, NTD and dsDNA are colored red, yellow, cyan, magenta and green, respectively. (B) Schematic model of a single dwell-burst packaging event in the mechanochemical cycle of the phi29 packaging motor. During the dwell phase (green line), the ATPase motor is charged with ATP. During the subsequent burst phase (blue line) hydrolysis of the ATP results in the translocation of 10 bp of dsDNA in four 2.5 bp sub-steps associated with four hydrolysis events ( 21).

Biochemical and single molecule analysis indicate that the phi29 genome packaging motor operates in a complex, highly coordinated fashion during translocation ( 18–21), and that the mechano-chemical cycle is separated into a dwell phase and a burst phase (Figure 1B) ( 21). No translocation occurs during the dwell, as all five gp16 subunits release ADP from the previous hydrolysis cycle and load ATP in an interlaced manner. More recent laser tweezer experiments show that two distinct regulatory mechanisms coordinate nucleotide exchange during the dwell ( 22). During the subsequent burst, four gp16 subunits sequentially hydrolyze ATP, resulting in translocation of 10 bp of DNA in four 2.5 bp sub-steps. The role of the fifth subunit is not entirely clear, but it has been proposed to play a functionally unique regulatory role in aligning the motor with DNA for the next translocation burst ( 18, 20). Using altered DNA substrates, additional single molecule experiments suggest that the motor makes two distinct types of contact with the translocating DNA ( 23) during the dwell phase, the motor makes specific electrostatic contacts with the phosphate backbone of the DNA, whereas the motor uses non-specific contacts during the burst to actively translocate the DNA. It has also been shown that DNA rotates 14° during each 10 bp translocation burst, likely to maintain motor/substrate alignment, and that the magnitude of this rotation is coupled to the changing step-size of the motor as the head fills ( 20).

While extensive biochemical and single molecule analysis have provided a detailed kinetic scheme describing what happens during packaging, the molecular motions that underlie force generation and subunit coordination during translocation remain largely unknown. Additionally, how the motor transitions between translocation, termination, and initiation mode is similarly poorly understood. To visualize these events, we have thus been pursuing a hybrid structural approach wherein individual motor components are solved to atomic resolution via X-ray crystallography and then fitted into more moderate resolution cryoEM reconstructions of the entire complex ( 12, 24). We have previously determined atomic resolution structures of every component of the motor except for the ∼120 amino-acid C-terminal domain (CTD) of the packaging ATPase gp16 ( 11, 13, 24). Here, we describe the atomic structure of the CTD as determined by solution NMR. This structure, along with atomic structures of the connector, the pRNA, and the NTD of gp16, was fitted into a cryoEM map of phi29 particles stalled during packaging ( 25), resulting in the first complete near-atomic resolution model of an actively packaging motor. Additionally, analytical ultracentrifugation, fluorescence-based binding assays, and NMR chemical shift perturbation (CSP) experiments were used to characterize ATPase assembly and nucleic acid binding by the CTD. Together, these results show how the CTD interacts with other motor components and the translocating DNA and provides insight into how viral dsDNA packaging motors transition between genome processing and translocation functions.


Common descent and evolutionary theory

Vestigial structures are often homologous to structures that are functioning normally in other species. Therefore, vestigial structures can be considered evidence for evolution, the process by which beneficial heritable traits arise in populations over an extended period of time. The existence of vestigial traits can be attributed to changes in the environment and behavior patterns of the organism in question. Through examination of these various traits, it is clear that evolution had a hard role in the development of organisms. Every anatomical structure or behavior response has origins in which they were, at one time, useful. As time progressed, the ancient common ancestor organisms did as well. Evolving with time, natural selection played a huge role. More advantageous structures were selected, while others were not. With this expansion, some traits were left to the wayside. As the function of the trait is no longer beneficial for survival, the likelihood that future offspring will inherit the "normal" form of it decreases. In some cases the structure becomes detrimental to the organism (for example the eyes of a mole can become infected). In many cases the structure is of no direct harm, yet all structures require extra energy in terms of development, maintenance, and weight, and are also a risk in terms of disease (e.g., infection, cancer), providing some selective pressure for the removal of parts that do not contribute to an organism's fitness. A structure that is not harmful will take longer to be 'phased out' than one that is. However, some vestigial structures may persist due to limitations in development, such that complete loss of the structure could not occur without major alterations of the organism's developmental pattern, and such alterations would likely produce numerous negative side-effects. The toes of many animals such as horses, which stand on a single toe, are still evident in a vestigial form and may become evident, although rarely, from time to time in individuals.

The vestigial versions of the structure can be compared to the original version of the structure in other species in order to determine the homology of a vestigial structure. Homologous structures indicate common ancestry with those organisms that have a functional version of the structure. Douglas Futuyma has stated that vestigial structures make no sense without evolution, just as spelling and usage of many modern English words can only be explained by their Latin or Old Norse antecedents.

Vestigial traits can still be considered adaptations. This is because an adaptation is often defined as a trait that has been favored by natural selection. Adaptations, therefore, need not be adaptive, as long as they were at some point.


Evolution&rsquos &lsquoUnnecessary&rsquo Organs

W hy do you have an appendix? Or wisdom teeth? Or something called a coccyx? Since the days of Darwin, numerous scientists and educators have argued that “useless” or “vestigial” organs prove the theory of evolution. These organs, they say, are like leftover scaffolding that had previously performed vital functions in mankind’s “pre-human ancestors.” They just haven’t evolved their way into oblivion quite yet.

“Organs or parts … bearing the plain stamp of inutility are extremely common, or even general, throughout nature,” Darwin explained in O podrijetlu vrsta. “It would be impossible to name one of the higher animals in which some part or other is not in a rudimentary condition.” His prime examples: the appendix and the coccyx (tailbone).

Subsequent specialists greatly expanded Darwin’s original list of useless organs. In 1895, German anatomist Robert Wiedersheim compiled a list of human structures he considered vestigial, which came to be regarded as the official one. How many human body parts were on it? More than 180.

American zoologist Horatio Newman said this staggering number was “sufficient to make of a man a veritable walking museum of antiquities.” These organs represented “evidence that man has descended from ancestors in which these organs were functional,” he said. “Man has never completely lost these characteristics he continues to inherit them though he no longer has any use for them.”

Textbook publishers quickly joined the pack, saying the human body—with its myriad useless relics—is like an “old curiosity shop,” full of “showpieces” proving evolution.

The rapid embrace of the vestigial organ belief deepened the traction of the evolutionary theory, and also spawned new trends in the medical community. “There are undoubtedly cases where we know that certain vestigial structures are not only useless to man but worse than useless,” Henry Drummond wrote in The Ascent of Man. He called the appendix “a veritable death trap,” and also cautioned readers of the perils of other organs lurking inside of their bodies. Throughout much of the 20th century, medical practitioners removed appendixes, tonsils and other “dangerous” organs as routine operations.

The idea of vestigial organs is not a fringy, peripheral support of the evolutionary theory, but lies at its very heart. And the most frequently mentioned examples of these organs in mankind remain the appendix and the coccyx.

Appendix: The Last Shall Be First

The wormlike abdominal structure called the appendix has long occupied the lowest position on the organ totem pole. Darwin called it a leftover piece from mankind’s leaf-eating, pre-human predecessors. Many experts swallowed the theory, hook, line and sinker. The organ’s primary importance seemed to be only for the financial support of surgeons, and to provide fodder for tv sitcom writers.

For that reason, experts took note in 2009 when immunologist William Parker at Duke University Medical Center said, “Maybe it’s time to correct the textbooks. Many biology texts today still refer to the appendix as a vestigial organ” (LiveScience, Aug. 24, 2009).

Parker suggested the correction after he and his colleagues discovered that the appendix serves as a storehouse where good bacteria can lie in wait until they’re needed to repopulate the stomach after an episode of diarrhea or other intestine-emptying illness.

A separate recent study showed that the appendix conducts operations similar to those of the tonsils at the opposite end of the alimentary canal, which increase resistance to throat infections. (The tonsils, too, were long branded by evolutionists as useless and problematic.) A 2011 study showed that the appendix also helps generate, guide and train white blood cells, especially for fetuses and children. Valerie O’Loughlin, a professor of medical sciences at Indiana University, said it is “the site where a type of white blood cell called b-lymphocytes can be recognized and where the newborn and young child’s body can start to recognize certain pathogens that are in the [gastrointestinal] tract.”

The organ is far from useless, and removal of a healthy appendix under most circumstances today is considered medical malpractice.

The Tale of the Tail

Most of the evolutionary faithful maintain that the human tailbone is a leftover, useless part from mankind’s ape-like ancestors. Darwin explained: “[T]he os coccyx corresponds with the true tail in the lower animals. … [I]n many monkeys the basal segments of the true tail are embedded … [and] plainly correspond with the four coalesced vertebrae of the human os coccyx” (The Descent of Man, 1871).

Some later evolutionists argued that the human coccyx was more of a reptilian relic than a mammalian one: “The human coccyx is an evolutionary remnant of an ancestral, reptilian tail …” (William D. Schraer and Herbert J. Stoltze, Biology: The Study of Life).

Though evolutionists disputed whether it descended from a simian ancestor or a reptilian one, they agreed that the tailbone is largely useless and, therefore, a proof of evolution.

In 1994, however, renowned anatomy professor David Menton produced evidence disproving the idea that the coccyx is vestigial. “[M]ost modern biology textbooks give the erroneous impression that the human coccyx has no real function other than to remind us of the ‘inescapable fact’ of evolution,” Menton wrote in Essays on Origins.

He explained that among the key functions of the coccyx is its acting as an anchor point for several converging muscles from the ring-like arrangement of the pelvic bones. “The incurved coccyx with its attached pelvic diaphragm keeps the many organs in our abdominal cavity from literally falling through between our legs” (ibid). Removal of the coccyx often causes incontinence and serious difficulties with sitting, standing or giving birth.

The evolutionary faithful long considered the tailbone vestigial and pointed to it as evidence against creation. But the tailbone, too, was placed in the body for a purpose.

The Body Is One

Biomedical research made great strides in the latter half of the century, and experts shortened the list of “functionless organs” considerably. Research yielded more and more understanding about the importance of organs once called mere “accidents of nature.” One by one, they were proven to serve vital functions in the human body. For many biologists, Wiedersheim’s list—that once included over 180 vestigial human organs—is now down to zero.

Again, the idea of vestigial organs lies at the heart of the evolutionary theory. As recently as 2004, prominent evolutionist Douglas Theobald said, “Some of the most renowned evidence for evolution are the various nonfunctional or rudimentary vestigial characters, both anatomical and molecular, that are found throughout biology” (29+ Evidences for Macroevolution).

Yet, the idea of “vestigial” organs is deeply flawed even in strictly scientific terms.

The argument claims that the organs in question have no function. But such a conclusion cannot be arrived at scientifically. Without infinite knowledge, it is impossible to prove that something has no function. The most a scientist could say would be that, despite rigorous efforts, no clear function was discovered for a certain organ, but that a future experimenter may well uncover one.

The heart of the vestigial organ argument, then, is either an acknowledgment of ignorance (“I wasn’t able to discover the function”), or a scientifically flawed statement (“It has no function”). Observational or experimental science allows no place for such a statement. Reputable scientists acknowledge that the teaching of “vestigial organs” actually retarded the progress of science for years. Rather than experiment to discover the purpose of structures like the appendix or tonsils, they were called “vestigial” and removed.

So, how did such a flawed theory gain widespread acceptance? The idea is the product of men groping for evidence to back the theory of evolution.

Adherents of this theory didn’t immediately see a use for certain body parts, so they hastily, blithely branded those organs as useless—or even harmful. The notion was based on a lack of knowledge about how the human body functions. Even vitally important organs such as the parathyroid and thymus glands were considered vestigial until fairly recently, simply because experts didn’t understand their crucial purposes. And, despite the fact that modern science has found purposes for all organs in the body—and that future experimentation will certainly reveal even more—evolutionists still cite “vestigial organs” as one of the sturdiest proofs for evolution and against design by an intelligent Creator.

Why are these scientists willing to compromise their objectivity, which is one of the foundations of science?

Done With a Purpose

In the centuries leading up to the Scientific Revolution, the Catholic Church reigned as the primary authority and knowledge source for much of the world. The clergy often viewed scientists and their discoveries as a threat to Catholic doctrine, and sometimes embarrassed the church by striving to defend erroneous church teachings like geocentrism, which science offered empirical evidence against.

Competition intensified between science and the church, and, for some scientists, the desire to undermine the church’s authority became a primary motivation. Some scientists aimed to challenge God’s very existence as a way to discredit the underpinnings of religion. Takvo razmišljanje iznjedrilo je evolucijsku teoriju. Proponents of the evolutionary theory have sometimes undertaken studies with that conclusion already firmly in mind. Zadržavaju sve što mogu doprinijeti podržavanju argumenata za evoluciju. Sve ostalo često odbacuju ili umanjuju.

Long before the evolutionary theory was hatched, the Apostle Paul labeled such movements “science falsely so called” (1 Timothy 6:20). True science upholds objectivity and seeks truth free of any agenda. A person’s understanding of the human body will be incomplete until he accepts that it is “fearfully and wonderfully made” by a Supreme Being (Psalm 139:14). This Creator designed mankind after His own image (Genesis 1:26-27). He placed organs within the body in a specific way and for a specific purpose, and He called His design “very good” (verse 31).

The advancement of science only brings the perfection of the Creator’s designs more clearly to light. Evolutionists strive to present plausible-sounding arguments to the contrary, but this only reveals how blind and irrational the evolutionary religion truly is. The astonishing perfection and purpose in every element of the body’s design should deepen man’s faith in the divine intelligence behind our existence (Romans 1:20). But when evolutionists are confronted by proof of this Divinity, they instead resort to extremes of ludicrousness, striving to attribute the wonders of the human body to blind coincidence. In so doing, they unknowingly exercise a blind, deceptive and irrational religious faith.

Christians face a difficult battle against this blind faith in science, which is often found even among religious adherents. We must be able to recognize this blind faith in order to weigh evidence objectively. If we resist the vain, intellectual allure of this blind but fashionable faith, then we make it possible for the wonderment of God’s masterful biological designs to boost our faith in the Omnipotent Creator. And His purpose for our lives is as perfect as the bodies He designed to sustain us!

Sidebar: The Appendix Why So Disease Prone?

If the appendix was created for a purpose and is indeed functional, why do many suffer from appendicitis, requiring the organ to be surgically removed?

Disease and degeneration do not reflect on the suitability of God’s original design, but are the result of man rejecting God’s law, and instead living by his own ideas. Additionally, appendicitis is common only in populations that subsist on a very highly processed and refined modern diet. Societies enjoying a high-fiber diet of vegetables, fruits and unrefined grains have very low instances of the disease.


Vestigial traits

When an anatomical structure appears frankly inept, it is probably a vestigial trait. This is a feature that no longer does whatever made it advantageous enough to evolve in the first place. If we could embody evolution as a person, then he or she would be creative but inherently lazy. If something is not being used then why bother maintaining it? It’s hard to say why they haven’t disappeared altogether but give it another million years and perhaps they will.

Some snakes, for example, still show vestigial traits harking back to their four-legged ancestry. Male pythons have little claw-like structures towards the tail, which, although they aid courtship, are all that remain of their hindlimbs.

Cave fish have lost most of their eyes. Vladimir Wrangel/Shutterstock

Some cave fish have, over generations, lost most of the components of their eyes because sight uses up a lot of energy and isn’t helpful when you live in complete darkness. Many flightless birds, such as penguins and Galapagos flightless cormorants, have wings so small that they are effectively redundant in terms of flying.

Closer to home, the human appendix is a good example of a vestigial trait (although there’s now some evidence it may not be useless after all). But there is a weirder one, the plica semilunaris. The next time you look into the eyes of a loved one (it’s more awkward with a stranger on the bus), look at that little pink, triangular bit on the inside of each eye.

It’s not completely vestigial, as it helps ensure that tears drain properly and gives a slightly greater range of movement, but that’s not its original function. Long ago, when we shared a recent ancestry with birds and other reptiles, this little structure would have formed a nictating membrane, or “third eyelid”, to provide further protection to our eyes. So, although we have lost this clear, extra eyelid, evolution has upcycled it for another use.


Is there a name for the evolutionary loss of vestigial structures? - Biologija

State Standard Objectives and Codes

1) Identify the following components of natural selection, which can lead to speciation: potential for a species to increase its numbers, genetic variability and inheritance of offspring due to mutation and recombination of genes, finite supply of resources required for life, and selection by the environment of those offspring better able to survive and produce offspring. [S4-C4-PO1]

2) Explain how genotypic and phenotypic variation can result in adaptations that influence an organism’s success in an environment. [S4-C4-PO2]

3) Describe how the continuing operation of natural selection underlies a population’s ability to adapt to changes in the environment and leads to biodiversity and the origin of new species. [S4-C4-PO3]

4) Predict how a change in an environmental factor (e.g., rainfall, habitat loss, non-native species) can affect the number and diversity of species in an ecosystem. [S4-C4-PO4]

5) Analyze how patterns in the fossil record, nuclear chemistry, geology, molecular biology, and geographical distribution give support to the theory of organic evolution through natural selection over billions of years and the resulting present day biodiversity. [S4-C4-PO5]

° Can create or negate potential for a species to increase its numbers.

° Genetic variability and inheritance by offspring is the result of mutation and recombination of genes à recessive lethal traits, heterozygous advantage, disease/parasite resistance.

° Availability of resources determines the success of a species.

° The environment determines those organisms best able to survive and produce offspring.

° Fitness is the ability to survive and reproduce.

° Comprehend how natural selection leads to Biodiversity.

° Define and identify adaptations for each ecosystem (i.e., plants à waxy coating, spines, root systems, leaf size, ability to store water AND animals à burrowing, nocturnal, water tight skin, primary water source is the food they eat, adaptive camouflage)

° Population reduction à species extinction (genetic bottlenecks, etc) Possible examples include: California Condors, Cheetahs, Grizzly Bears and Lemurs, Panda, Florida Panthers (constantly changing).

° Environmental factors impact parental survival which determines the makeup of the next generation.

Fitness (reproductive success)

Disease and/or parasite resistance

Changes in environment (examples: drought, rainfall, habitat loss, non-native species, etc.)

° Biochemical similarities – DNA, protein similarities.

° Fossils, transitional forms

° Geographical distribution of species

Nuclear Chemistry – radioactive dating

Questions and Facts to think about and incorporate into your website.

1. When did individuals start to think about evolution? Give some examples of individuals including what was thought.

People have been thinking about evolution since BC ages and have gradually changed their perspectives about evolution:

  • Anaximander wondered about changes from fishlike organisms to land ones
  • In the 1700s, Carl von Linne believed that species were fixed and unchanged
  • JB de Lamarck was one of the first to come up with the idea of evolution, changes in species
  • Charles Darwin made the theory of evolution famous and promoted Natural Selection

2. What three basic premesis did Darwin propose to support his argument of evolution? Give a brief explanation of each.

  • Members of any species increase in number naturally à due to high reproductive potential
  • Competition for declining resources à resources are scarce, and organisms are kept in check when they contend for them
  • The survival of the few à only the strongest can get necessary resources (Natural selection), so weaker organisms die off

3. For the following scientists, summarize their view and mechanism of action concerning evolution:

· Created the system of organization for naming animals (genus species), that is the basis of taxonomy

· He believed in the biblical view that all organisms were as they were created, they were fixed and did not change

b. Jean Baptiste de Lamark

· Fact à believed that species change over time

· Course à progressive change, along the course of a ladder

· Mechanism à animals must adapt to changes in environment, through inheritance of acquired characteristics

4. How did both Charles Darwin and Alfred Wallace both come to the conclusion of evolution via natural selection? What and/or who influenced Darwin and Wallace to come to such conclusions?

Wallace wondered why some animals lived and others died. He realized that only the strongest animals lived to continue a species and settled on the idea of survival of the fittest. Darwin connected the variations in species in the Galapagos to evolution, and his reasoning for these differences was that only the strongest organisms would be able to adapt and survive, and their traits would be carried on. Both Wallace and Darwin used the essay on Population by Malthus to come to the conclusion that natural selection was involved in evolution.

5. Why did Darwin delay publication of his book “On Origin of Species?”

Darwin waited years before actually publishing his ideas. He had waited a couple years before writing a small first draft and then took more time to expand it. Because religion was so important at the time, he knew he had to expand his findings and explanation, and provide more evidence for his theories. He told few people about his ideas, and planned for his wife to publish his work should he die. But after about 20 years, he received Wallace’s work, which convinced him to publish his book, knowing that someone else had similar ideas.

Despite evolution's potential for controversy, it remains an essential element of any biology course. As Theodosius Dobzhansky said in his 1973 article of the same name, in American Biology Teacher, "Nothing in biology makes sense except in the light of evolution." Based on this article and on your work thus far in the course, think about why evolution is considered the cornerstone of biology.


Vestigial Structure Examples

Vestigial Structures in Fruit Flies

The common laboratory organism Drosophila melanogaster (the fruit fly) was one of the first to have its small genome mapped. During the mapping of the genome, scientists found many genes that if inactivated would cause vestigial mutations in the fruit flies. Hundreds of mutations were found that could produce vestigial structures. The wings, eyes, feet, and many organs could become vestigial through the deactivation of different genes. Using these flies as a model, scientist were able to accurately and clearly show how vestigial structures can arise through simple sexual reproduction, and how these vestigial structures could become frequent in a population.

Populations of fruit flies have been developed to have different vestigial structures for different purposes. Flies with vestigial wings are bred and used as feeder insects for pet frogs. Because humans supply an environment with plenty of food and no predators, the flies can still grow and reproduce. When it is time to feed the pet frogs, the flies can be easily tapped out of their culture tube. With no wings, the flies cannot fly away or otherwise escape the frog’s enclosure. In other cases, scientists may want to test the sensory organs of flies. By producing flies with vestigial eyes, for instance, the other senses can be tested without the variable of sight being added in.

Vestigial Limbs

Before the days of fossil records, x-rays, and DNA analysis, it was long assumed that snakes gave rise to lizards, not the other way around. When scientist started really observing the anatomy of snakes, they began to realize that many snakes still have vestigial structures where a lizard’s limbs would have been. Other vestigial structures in snakes, such a vestigial lung, were also evidence that snakes evolved from an ancestor that used two lungs and walked with 4 limbs. This, coupled with a fossil record that showed a decline in limb size leading to snakes and mounting DNA evidence revealed that the opposite was true: snakes came from lizards and not the other way around.

Loss of limbs is also seen in whales. The ancestors of whales were organisms somewhat like hippos, which slowly moved into the water. In the water, limbs create drag and making swimming less efficient. Slowly, the front limbs were changed to fins, and the back limbs were lost entirely. However, the skeleton of a whale will reveal a set of bones, not attached to the main skeleton, where the hind-limbs used to be. The bones do not leave the body and seem to only provide minor support to the muscles. These vestigial structures are a clue that like snakes, whales came from a 4-legged ancestor.

Vestigial Structures in Humans

Humans have a wide range of traits that are considered vestigial structures. One of the most obvious is the tailbone, or trtica. The coccyx is a small series of fused vertebrae that exist at the base of the pelvis. In our ancestors, it probably formed a large prehensile tail, capable of grabbing branches. As we evolved into bipeds, less time was spent in the trees and more time spent walking and sitting on the ground. As seen in the transition from monkeys to great apes, the loss of a tail represents a less arboreal, or tree-based lifestyle.

If you’ve ever had your wisdom teeth removed, you know that vestigial structures can be more than useless. In the case of wisdom teeth, the human skull has been shrinking as we evolve. Part of the reason is that our diet has become much softer and easier to chew because we cook or otherwise process our food. While our jaw has become smaller, the last tooth in the jaw has not been lost. In most people, this tooth will cause pain as it comes in and may deform the other teeth in the jaw.

Have you ever gotten goose-bumps when you get cold? When this happens, small vestigial muscles at the base of your hair follicles pull the hair so it stands upward. In our ancestors, this created a much fluffier and thicker coat, which could hold more air. An animal’s coat functions by trapping air and heating it up. Humans have lost the coat but retained the muscles that make hairs stand up. The pathways that cause the hair to stand up can also be considered vestigial. While they do help us know we’re cold, they certainly don’t help warm us up.


Most recently, evolutionists have proposed that so-called pseudogenes are vestigial, but whether such “junk” DNA has no function at all is hotly debated. Yet even if these pseudogenes were in fact nonfunctional, why would that be evidence against Biblical Creationism which expects diminished functionality and mutation in a Fallen world?

I realize that other examples of the vestigial argument could be examined and I hope to do so at some later date, but here I only wish to establish that this line of argumentation is based on a logical fallacy [or two]…

Each time the evolutionists puts forth the claim that an organ or structure is vestigial, t faithful evolutionist commits one of two erros:

1] When no function is presently evident [and our present ignorance is typically remedied later], the evo presumes that a nonfunctional structure or organ is an “evolutionary leftover” of some proposed ancestor when nonfunctional organs [like the eyes of blind cave fish] are better explained by the degenerative trend of a world affected by the Fall.

2] When the function of a “vestigial” organ or structure is known AND the organism is presumed to have evolved, the evo further presumes that these organs or structures evidence dimished functionality from the proposed ancestral organism. It’s a lot of presumption, or what I typically term imagineering.

The problem then with vestigial arguments is that the evo has to beg the question of whether microbes-to-man evolution occurs in order to suggest that some organs and structures are vestigial so that he can use vestigial oragns and structures as evidence for the goo-to-you evolutions he’s presuming to begin with! Which makes it all a rather circular argument: The evo must beg the question of microbes-to-man evolution in order to beg the question of vestigiality in order to support his claim of darwinian evolution [and for vestigial organs for that matter!]. It’s very much a chicken and the egg scenario.

Which begs the question of why they have to resort to such weak arguments to begin with….