Поставите питања везана за еволуциону биологију

[winux59]

Bez ulazenja u diskusiju... posto pojedini genijalci pricaju da su pronadjene "savremene ptice" pozivajuci se na clanak koji ocigledno nisu ni videli... samo ovo:

http://www.nature.co...df/322677b0.pdf

http://en.wikipedia.org/wiki/Protoavis

evo fosila protoavisa

Navodno nema dovoljno kostiju da se sto posto utvrdi da je to ptica, jer se to ne uklapa u model evolucije.

A sada slika Lucy

Ovde ima i vise nego dovoljno kostiju da se vidi da je to prelazna forma, i jos koleno je nadjeno 1,5 klimoetar dalje od ostatka kostiju. Naravno ovo bi se uklapalo u teoriju.

Moje pitanje je koga bre vi to za.ebavate? Jel to vasa ozbiljna nepristrasnsa nauka?

Odgovor na protoavisa, na tvrdnje iznete na talkorigins.

So Called Bird Evolution

(Talk.Origins quotes in blue)

• Coelophysis (late Triassic)-- One of the first theropod dinosaurs.
  

The big problem here is that there is a 'true' bird (there is only one paper describing it) called Protoavis that would be older than Coelophysis thus eliminating Coelophysis as an ancestor to birds, unless one assumes Coelophysis is older than there is evidence to suggest.

• Deinonychus, Oviraptor, and other advanced theropods (late Jurassic, Cretaceous) -- ... The particular fossils listed here are are not directly ancestral, though, as they occur after Archeopteryx.
  

So they know that they do not have an actual ancestor here. and hence no real evidence that this alleged ancestor actually existed. The fact Deinonychus and Oviraptor are dated as younger than the birds Protoavis and Archaeopteryx.

Evolutionists will claim that there is an implied relationship, like resembling your brother, mother or cousin, but they do so without objective evidence. To conclude that a relationship exists in such case requires assuming that there is a common ancestor and thus the argument is circular.

• Lisboasaurus estesi & other "troodontid dinosaur-birds" (mid-Jurassic) ... These really could be ancestral.
  

Lisboasaurus is dated as younger than the bird Protoavis thus eliminating Lisboasaurus as an ancestor to birds, unless one assumes 'Lisboasaurus is older than there is evidence to suggest.

GAP: The exact reptilian ancestor of Archeopteryx, and the first development of feathers, are unknown.

Translation: they really do not have a clue about the origin of feathers.[1] The Bible however dose have one. "In the beginning God created..."

Early bird evolution seems to have involved little forest climbers and then little forest fliers, both of which are guaranteed to leave very bad fossil records (little animal + acidic forest soil = no remains).

Here is a nice excuse for the lack of evidence. It is interesting that this gap occurs right where any evidence of the development of flight would occur. It is right where Creationists would predict it to be.

• One possible ancestor of Archeopteryx is Protoavis (Triassic, ~225 Ma) -- A highly controversial fossil that may or may not be an extremely early bird. Unfortunately, not enough of the fossil was recovered to determine if it is definitely related to the birds.
  

Given the fact that many so called transitional forms are based on extremely fragmented evidence, the most likely cause of the controversy is the fact that by predating its alleged ancestors, it blows the entire dino to bird evolution scheme to bits.

Another possible source of controversy is that the fossil has only been examined by ornithologists (Bird experts); however the fact that they found it to be a bird is a plus.

Some have claimed that the bones of Protoavis are actually from more than one animal, however even if that were true some if not all of the bones would still most likely be from birds, otherwise it is unlikely that ornithologists would have concluded that Protoavis was a bird. So in any case Protoavis is a strong argument against dinosaur to bird evolution.

The Protoavis was clearly a bird. In fact Protoavis is more like living birds than Archaeopteryx. What makes it a problem for dinosaur to bird Evolution is that it is dated as older than all its alleged dinosaur ancestors, unless one assumes the alleged dinosaur ancestors are older than there is evidence to suggest.

Reference: Protoavis

Reference: Protoavis - Wikipedia, the free encyclopedia

Reference: Bird evolution: discontinuities and reversals

• Archeopteryx lithographica ([ Late Jurassic, 150 Ma]) ...
  

Archaeopteryx was a fully flying and perching bird; with no apparent relationship to Protoavis. Recent discoveries seem to have shown that there are enough similarities betweenArchaeopteryx and Dromaeosaur that they can be considered varieties of the same kind of animal. This includes evidence from Dromaeosaur's feathers, that it could fly.

Furthermore Archaeopteryx is dated as 20 million years older than Dromaeosaur. Archaeopteryx could not have evolved from Dromaeosaur. In fact Archaeopteryx is older than most of its alleged ancestors; which is a BIG problem for evolutionists, unless one assumes the alleged dinosaur ancestors are older than there is evidence to suggest.

Evo ovako izgleda odgovor naucnika na vase tvrdnje.

[winux59]

o tome mu ja i pricam svo vreme. Ja iskreno nisam procitao clanak pa nisam hteo ni da ulazim u diskusiju o tome. Ali problem kreacionista je to sto nikad ne pogledaju drugu stranu price. A kada o evoluciju slusas samo od strane kreacionista i antievolucionista naravno da ces da je dozivis kao bogus. Tako sam je i ja dozivljavao ali nije trebalo puno evolucionista da procitam da shvatim da nije tu sve onako kako predstavljaju kreacionisti.

Secam se da mi je jedan tekst igrom sluchaja u nacionalnoj geografiji skrenuo paznju po pitanju cele price koju kreacionisti serviraju.

Dakle, slusas li ti sam sebe?

Ja navedem citat iz odredjenog clanka, kako ja znam sta pise u clanku ako ga nisam citao? da nisam gledao u pasulj ili u solju kafe?

Zato ti avocado kaze da ja nisam citao taj clanak, ti mu naravno poverujes jer to avocado kaze.

Pogledao sam ja i drugu stranu to jest vas izvor informacija talkorgins, i na to sam odgovorio.

[grigorije22]

Da, citao sam te "najverovatnije" pricice vec na sestodnevu... ali mi nije jasno kako bilo ko moze da ih uzme za ozbiljno.

Postoji mnogo sisara koji su veoma spori i ne mogu da beze... recimo lenjivci.

Sa druge strane postojali su mnogi veoma agilni dinosaurusi, pa i leteci dinosaurusi a i oni koji su ziveli u morima.

Takodje, ne nalazimo sisare samo na planinama.

Nema nista od te pricice... nije interesantna ni na prvi pogled.

A sto se tice "ekoloske zonacije", bar onako kako je objasnjena u Roth-ovoj knjizi, to je potpuna budalastina... slicna ovoj prici o bezanju... ali jos gluplja... cak i da dinosaurusi jesu svi ziveli u nizim predelima a svi sisari na planinama, poplava koja bi prekrila planinu ne bi tim redosledom slozila leseve tj. fosile... voda kada se podize, ona nosi stvari sa sobom, voda ne zatrpava (sta god pojedini genijalci pricali)... a ako neko pozeli detaljnije objasnjenje, dacu ga...

Ne znam za debate... odgovor naucne zajednice je ocigledan u cinjenici da Sanford svoja pisanija ne moze da objavi u peer reviewed casopisima... Babic vam je vec postavio par tekstova u vezi sa Sanfordom a ovaj se meni najvise dopao:

http://letterstocrea...ess.com/stan-4/

(prvo gazi Behe-a, skroluj nize da stignes do Sanforda)

Ali u sustini... ne znam ni zasto bismo raspravljali o teoriji kada su cinjenice lako proverljive... teoretisati o lako proverljivim cinjenicama je besmisleno... to sto vi radite sa Sanfordom, je kao kad bi me godinama ubedjivao da tu, odmah iza ugla postoji pekara sa najboljim burekom na svetu, ali nikada nisi otisao da probas taj burek niti mozes da mi ga doneses... kao sto rekoh, imamo sekvencirane gene ljudi starih nekoliko hiljada godina... po ovoj teoriji njihovi geni bi bili daleko savrseniji, odnosno nasi bi imali ogroman broj negativnih mutacija naspram njih... medjutim, mi vidimo da to nije tako... case closed... nice try... have another beer...

Za ovo u vezi potopa i Sanforda znas vec gde su odgovori.

[Avocado]

Za ovo u vezi potopa i Sanforda znas vec gde su odgovori.

Ne vidim ni jedan normalan... a buncanje ludaka ne zelim da tumacim... ako ti mozes to da prevedes na jezik normalnih ljudi, slobodno napisi ovde... koliko god se sa tvojim stavovima ne slazem... ti se bar izrazavas kao normalna osoba...

[grigorije22]

Ne vidim ni jedan normalan... a buncanje ludaka ne zelim da tumacim... ako ti mozes to da prevedes na jezik normalnih ljudi, slobodno napisi ovde... koliko god se sa tvojim stavovima ne slazem... ti se bar izrazavas kao normalna osoba...

Ne mogu nisam kompetentan dovoljno u vezi genetike i geologije. Mogu samo da postavim sta si pisao ovde na sta ce on da

odgovori i to je to. I ono sto najvise mogu je da te obavestim da ti je odgovoreno, pa ako te zanima mozes da procitas odgovor ma kakav da je.

[Млађони]

Ja navedem citat iz odredjenog clanka, kako ja znam sta pise u clanku ako ga nisam citao? da nisam gledao u pasulj ili u solju kafe?

Idalje potvrdjujes da nisi procitao ceo clanak .

[Avocado]

Ne mogu nisam kompetentan dovoljno u vezi genetike i geologije. Mogu samo da postavim sta si pisao ovde na sta ce on da

odgovori i to je to. I ono sto najvise mogu je da te obavestim da ti je odgovoreno, pa ako te zanima mozes da procitas odgovor ma kakav da je.

Nije ni on kompetentan u oblasti genetike i geneologije + nije normalan... tako da zaista nema potrebe da mi prenosis bilo sta... a to sam te vec vise puta zamolio...

[grigorije22]

Nije ni on kompetentan u oblasti genetike i geneologije + nije normalan... tako da zaista nema potrebe da mi prenosis bilo sta... a to sam te vec vise puta zamolio...

Pa i ne prenosim ovde direktno zato sto ne smem, a sto se tice kompetentnosti on je ipak zavrsio odredjeni fakultet ima diplome i bavi se istrazivanjem. E sad druga je stvar ako ti mislis da on laze da nije zavrsio nista da nema nikakvu diplomu,da jednostavno nema veze sa genetikom zato sto podrzava kreacionizam i govori nesto sto nije opsteprihvaceno u naucnim krugovima.

[Млађони]

Pa i ne prenosim ovde direktno zato sto ne smem, a sto se tice kompetentnosti on je ipak zavrsio odredjeni fakultet ima diplome i bavi se istrazivanjem.

Daj kad se toliko hvali time, gde se tachno bavi istrazivanjem? U kom centru/laboratoriji i gde mu je ta diploma?

Jel ima to negde da se vidi?

[Avocado]

Pa evo Grišo da ti odgovorim ovde na ovaj tekst... posto tamo to nije tema...

Nemoj da kupis lose navike od onog vaseg genijalca... tako i on ako se neki pojam pomene kao deo argumenta samo iskopira kreacionisticki tekst o tom pojmu bez obzira da li to ima ikakve veze sa tim argumentom...

Tekst koji ti kopiras samo tvrdi da mutacija gena koji sluze za sintezu vitamina C predstavlja negativnu mutaciju i da kao takva nije dokaz napretka nego nazadovanja i dokaz tzv. genetske entropije... (inace, niko i ne tvrdi da je to dokaz napretka, tekst koji kopiras je tipican primer straw-man argumenta)

Taj tekst nije odgovor na argument koji sam ovde napisao... naprotiv ja ovde i navodim tu mutaciju kao "pokvareni deo" gena... a argument je da inteligentni dizajneri ne stavljaju pokvarene delove u svoj dizajn... nece niko da dizajnira automobil i da kaze, ovde u gepeku ce da budu neki farovi koji ne rade... to je besmisleno...

Doduse, za ovaj primer, ti mozes da tvrdis da je taj gen nekada bio funkcionalan kod svih stvorenih zivotinja, pa i coveka... ali onda moras da objasnis zasto se pokvario potpuno identicno, istom vrstom mutacije na istom mestu u genu kod jedne grupe vrsta koje su po TE srodne a na sasvim drugom mestu kod druge grupe vrsta koja je opet po TE srodna... onda tu vise nemas samo Tvorca koji je stvarao "po temama" vec Kvaritelja koji je kvario "po temama"...

TE to jednostavno objasnjava... taj gen je pokvaren u toj grupi (Haplhorini) na identican nacin jer se pokvario kod pretka i svi dalji potomci su ga nasledili tako pokvarenog... u drugoj grupi (Cavidae) je pokvaren na sasvim drugom mestu a opet identicno medju clanovi te grupe iz istog razloga... to ti je upravo dobar primer tzv. ugnjezdene hijerarhije...

[grigorije22]

Molecular Biologist Daniel Criswell

"In 1994, a group of Japanese scientists identified a DNA sequence in humans that had many similarities to the rat gene that codes for the enzyme (L-gulono-γ-lactone) that catalyzes the last step of vitamin C synthesis (Nishikimi et al. 1994). The human pseudogene sequence discovered has four of these 12 exons. (Exons are the modular coding regions of a gene.) These four human exon sequences have many characteristics of a pseudogene. There is a 70-80% sequence homology between the rat and human sequences depending on the exon, and two stop codons. Later analysis confirmed that these four exons are present in other primates as well (Inai, Ohta, and Nishikimi 2003). Humans are missing only the final enzyme for the last step in synthesizing vitamin C, but have all of the other enzymes necessary to convert glucose into vitamin C.

It would seem from the evidence of a potential human pseudogene for L-gulono-γ-lactone and the presence of the other enzymes necessary for synthesizing vitamin C that humans have lost the ability to make vitamin C. However, there is more to this story. There are only four exons for the gene encoding L-gulono-γ-lactone in humans. Two-thirds of the homologous rat gene is completely missing. Most pseudogenes represent 90% of the entire functional gene. This DNA sequence, labeled as a pseudogene, might have an entirely different function than the rat gene.

Stating that only the last enzyme is missing for the pathway to convert glucose to vitamin C might imply to the untrained individual that there is a biochemical pathway that leads to a dead end. Actually, the biochemical pathway that leads to the synthesis of vitamin C in rats also leads to the formation of five-carbon sugars in the pentose phosphate pathway present in virtually all animals (Linster and Van Schaftingen 2007). There are several metabolic intermediates in this pathway illustrating that these substances can be used as precursors for many compounds in the cell. In the pentose phosphate pathway, five-carbon sugars are made from glucose (a six-carbon sugar) to be used in the synthesis of DNA, RNA, and many energy producing substances such as ATP and NADPH (Garrett 1999). Animals that synthesize vitamin C can use both pathways illustrated in the simplified diagram below. Humans and the other animals "less fortunate" than rats only use the pentose phosphate pathway.

There is no dead end or wasted metabolic intermediates, and there is no need to have the enzyme to make vitamin C since humans are able to get all of the vitamin C they need from food substances.

Thousands of human pseudogenes have been catalogued, but in spite of the similarities to functional genes, the exact role of pseudogene sequences in the genome are not known by any scientist. It is not necessary to assume that pseudogenes are remnants of once functioning genes that have been lost and now clutter the genome like junk in a rubbish heap. It is possible that these regions of DNA do have a role in human and animal genomes and this role has not been discovered yet. Over 100 years ago, Robert Wiedersheim hypothesized that the human body had more than 80 organs that lacked any function simply because it was unknown at the time what these organs did (Wiedersheim 1895). They were assumed to be vestigial or "junk" leftovers from evolutionary history and several of these organs are still presented this way in biology textbooks today. The science of genomics is in the same position today. Just because scientists do not currently know the function of a portion of DNA does not mean that it does not have any function and therefore it is an evolutionary leftover. It has been reported that pseudogenes play a regulatory role in yeast for the functional genes that they share sequence homology with (Hirotsune et al. 2003). There needs to be more research in this area to verify these claims, but at least there are some indications of a functional role for pseudogenes in the human genome."

http://truthmatters.info/2007/05/28/dr-max-on-vitamin-c-and-plagiarism/

[grigorije22]

Shared Errors in the DNA of Humans and Apes

David A. Plaisted

It has been claimed that there are shared "errors" in the DNA between humans and apes, and that this shows that humans and apes must have a common ancestor, because the Lord would not have inserted common errors in their DNA. These errors are generally in the form of pseudogenes, which are genes that have lost their function for some reason, often because control sequences around them are not present. Here are some thoughts about these shared "errors" in DNA. The following material has extensively been modified since Edward Max's first response to it.

1. At first glance, this appears to be a strong argument for evolution. Indeed, I found it troubling for a while.

2. However, we are still learning, and it is hard to know when a part of the DNA is beneficial or harmful. How do we know for sure what is an error? Even the so-called junk (nonfunctional) DNA may have a function that we do not yet understand. For example, an article in Science (4 April 1997, page 39) suggests that "satellite DNA," which some researchers regard as nonfunctional, may have a function. See also Science 1994, Feb 4 pp. 608-610. This whole area is sufficiently new that it is best to wait a little longer. We should also look at shared properties of the DNA between many species, and see if they can consistently be placed in an evolutionary tree. If not, then this calls into question the human-ape connection.

3. Mutations are not completely random. It's possible that the same kinds of mutations tend to occur in the same way (for example, where the DNA folds, or whatever. Dan Hughes also suggests that DNA might tend to adopt a low energy state.) This could explain many common errors. Note that mutations in a population can be expected to obey more regularities than those among individuals, because of the similarities in survival benefits and the laws of large numbers.

4. Maybe the Lord inserted those similarities for a reason we do not understand. They could even have been inserted as tests of our faith. The Lord does not force any to believe, but gives opportunity to doubt for those who are seeking it.

5. Another possibility is that the Lord, when he cursed Adam and Eve after the fall, also cursed all life by introducing errors into the DNA. One could expect that similar species were cursed in a similar way, out of fairness.

6. Edward Max's argument is based on the fact that these shared sequences are really errors, that is, mistakes. It seems strange to call something an "error" when it occurs in a nonfunctional part of the DNA. Since that part of the DNA is nonfunctional, it doesn't matter what occurs there, so there is no justification for calling some of the sequences errors.

7. Something has to appear in the nonfunctional part of the DNA. Why should it be one thing rather than another? Just by chance (accident) there are likely to be sequences that resemble genes, but this says nothing about their origin. Do we expect that the Lord would have deliberately avoided common subsequences at common locations just so that we would not think there was common descent?

8. Let us consider humans and apes. Since they are so similar, one would expect that they had many similar genes at the creation in similar locations in the genetic material. Also, with the change in environment since then, one would expect that some of these genes would no longer be necessary, such as the gene for synthesizing vitamin C, and that there would be a few such genes in common between apes and men. Now, point mutations arise all the time, and if they are fatal or harmful, they will disappear from the population (have a small frequency). If they are neutral, they can be passed on. So it is reasonable that point mutations inactivating the vitamin C synthesizing genes would occur in both humans and apes, and be preserved in both, since these genes have little benefit now. Thus we would get a pseudogene in the same location in humans and apes. It could have been present in the individuals on the ark, for example. This probably would occur for a few other genes, as well. For organisms that are less similar, this still could happen, but less often. So we would expect to find a pattern of common pseudogenes that reflects the similarity between organisms, but not as an evidence of common descent.

Actually, the LGGLO pseudogene (an inactivated Vitamin C synthesis gene) has been found in one human so far and no apes, according to Edward Max, but in his essay he predicts that it should be found in apes, too. In fact, given the similarity in the DNA of humans and apes, that is a reasonable prediction. There are other examples of common pseudogenes that he says have been found in humans and apes, but I do not know yet if they occur in exactly the same form in humans and apes, or in how many individuals they have been found, or how many base pairs they have. Even if they do occur in the same form, this would be a problem for evolutionary theory, I think, because neutral mutations tend to be eliminated from populations, according to the talk.origins archive, and one would not expect a neutral mutation to persist for so long. Some neutral mutations can spread to the whole population, but this generally takes a very long time and has a low probability. (The chance that this will happen is proportional to the frequency of a neutral mutation in the population.) By seeing how much variation exists between copies of the mutated region in different organisms, one could estimate its time of origin and in this way check evolutionary timetables, since non-functional DNA probably mutates at constant rates. One would not expect to find a large number of shared neutral mutations among all humans and apes, in any event. Also, one would expect to find neutral mutations that had only spread to half or a fourth of the population, too, since they spread so slowly when they do spread. Furthermore, one would expect a gene to be inactivated in many different ways, so that exactly the same form should not be found today in all individuals. This would seem to imply a very severe population bottleneck at some time in the past.

9. It is even possible that the lack of ability to synthesize vitamin C could be an advantage in certain situations, although this appears unlikely. It could be that individuals without this ability would be forced to move to a different location, and this new location could turn out to be a more favorable habitat. The same could be true for the loss of some other genes.

10. Before being created, life was an idea in the mind of God. The relationship between the created life forms reveals something about how ideas develop in the Divine mind. We cannot say in advance how these ideas develop, which makes it difficult to draw conclusions about how the various life forms were interrelated at the creation.

By the way, concerning the junk DNA, it should also be mentioned that this DNA helps to concentrate certain kinds of mutations (crossovers, recombinations) at certain places in a protein molecule, and this can be a valuable function. The recombinations are likely to occur between the pieces of a gene, and not in the midst of it. This could have a useful function. However, this should only be dependent on the length of the junk sequence, and not its content.

The talk.origins site about this subject is carefully reasoned and does a fairly good job of presenting the creationist side, by the way, although it becomes somewhat biased and sarcastic at the end, in my opinion.

I wanted to comment in more depth about the effects of the curse. One of the purposes of the Creation is to illustrate spiritual truth. Before the entrance of sin, a perfect creation could faithfully represent spiritual reality. After the fall of man, this was no longer so. Now it would be necessary for the plants to bear thorns and thistles to teach spiritual lessons, and for the soil to be difficult to work. Jesus in his parables often referred to the things of nature as illustrations of the workings of good and evil. It is sad that the innocent animals had to bear the effects of sin which they had not caused, but their sufferings do help to bring to the mind of man the terrible effects of evil and lead him back to God.

[Avocado]

Molecular Biologist Daniel Criswell

Krisvelove tvrdnje su naivne... potpuna relativizacija znanja... kao, tacno je da taj gen skroz izgleda kao da je u pitanju mutirani gen koji je nekad sluzio za sintezu vitamina C i kojeg imaju ostali sisari ali MOZDA to uopste nije taj mutirani gen nego ima neku svoju funkciju koju mi ne znamo, te je potrebno dalje da istrazujemo... pa istrazi Krisvele... a dok ne istrazis ne pricaj stvari poput: mozda moj deda samo izgleda kao moj deda a u stvari je preruseni mrmot i necemo to znati dok detaljno ne istrazimo...

[Avocado]

Shared Errors in the DNA of Humans and Apes

David A. Plaisted

Ovaj tekst je vec prilicno lupetanje... ne zasluzuje odgovor... sta ti je u njemu interesantno Griso?

[grigorije22]

Ovaj tekst je vec prilicno lupetanje... ne zasluzuje odgovor... sta ti je u njemu interesantno Griso?

Pa recimo ovo pod 8 gde pokusava da objasni zasto se mutacija nalazi na identicnoj lokaciji.