Joined: Feb 02, 2006
Posts: 1745
Location: Colorado
Posted:
Wed Feb 20, 2008 5:56 am
I have posted this question on atheistforums as well.
So far no theist has been able to explain how they fit into their world view. Any attempt has been to deny they exist by stating they HAVE a use, or to ignorantly call them random mutations.
Vestigial organs do NOT have to be useless to be a vestige. They may also have taken on a new use or have gone through several new uses over time.
IF we were created in the garden of Eden a few thousand years ago, why are these organs around today?
For instance a Dolphin is born with hind flippers where feet would be on their land ancestors, or a human is born with a boney FUNCTIONAL tail. Never mind the damn appendix, we KNOW it has a new use today.
sfanetti Just Arrived
Joined: Feb 06, 2008
Posts: 9
Posted:
Wed Feb 20, 2008 8:04 am
The only theist argument I have ever heard for vestigial organs was that they did not exist. That they all actually have a function - we just don't understand it yet. Obviously not a positive definition, but it is rather hard to argue with willful ignorance.
baddogma Grand Poster
Joined: Feb 02, 2006
Posts: 1745
Location: Colorado
Posted:
Thu Feb 21, 2008 1:32 am
THey DO exist though. We have a dolphin in Japan that has hind flippers, we have whale skeletins with hind limbs, we have live humans with boney tails, we have reptiles and fish in caves with vestigial non-functional eyes, we have thousands. To simply deny they exist is sticking your fingers in your ears, closing you eyes and singing JESUS LOVES ME THIS I KNOW CUZ THE BIBLE TELLS ME SO at the top of your lungs.
Raligan Post Noob
Joined: Sep 10, 2007
Posts: 55
Location: Almost Texas, but still Oklahoma
Posted:
Thu Feb 21, 2008 2:59 pm
I've heard the snake's spurs explained as- get this- a remnant from when god cursed the devil (in "serpent" form) to crawl on his belly and eat the dust of the earth. Now, while most would agree that snakes don't eat dust, they do have vestigial legs.
So apparently, serpents had legs and were not called lizards by the ancient Hebrews. Good to know.
baddogma Grand Poster
Joined: Feb 02, 2006
Posts: 1745
Location: Colorado
Posted:
Thu Feb 21, 2008 11:56 pm
The neat thing is they ONLY have rear legs, the front are completely and for ever gone. The gene that makes them is altered, the are basically a neck and a backbone.
infidelguy Site Admin
Joined: Feb 21, 1999
Posts: 5137
Location: Atlanta, GA
Posted:
Fri Feb 22, 2008 1:11 am
Raligan wrote:
I've heard the snake's spurs explained as- get this- a remnant from when god cursed the devil (in "serpent" form) to crawl on his belly and eat the dust of the earth. Now, while most would agree that snakes don't eat dust, they do have vestigial legs.
So apparently, serpents had legs and were not called lizards by the ancient Hebrews. Good to know.
Interesting.. so this means then that there are over: 2,700 species of Satan. ha!
baddogma Grand Poster
Joined: Feb 02, 2006
Posts: 1745
Location: Colorado
Posted:
Fri Feb 22, 2008 1:44 am
And none of them talk!
Mr_C Intern
Joined: Jun 27, 2006
Posts: 202
Location: Dallas, TX
Posted:
Fri Feb 22, 2008 2:07 am
baddogma wrote:
And none of them talk!
Vestigial speech! Ha!
baddogma Grand Poster
Joined: Feb 02, 2006
Posts: 1745
Location: Colorado
Posted:
Fri Feb 22, 2008 2:47 am
I lold
Kelreth Graduate Thinker
Joined: Mar 04, 2006
Posts: 843
Posted:
Fri Mar 14, 2008 3:53 am
They have no way of proving it from their view with out heresy or making up some strange arguement
duderonomy Newbie First Class
Joined: Jun 30, 2004
Posts: 28
Posted:
Tue Apr 15, 2008 2:32 pm
"baddogma wrote:
And none of them talk!"
Fossils, Dead Sea Scrolls, History, Dinosaurs bones...none of them talk either, other than in what they leave behind as clues.
The whole argument that "remains' speak volumes" by what they are can go either way. God could have created animals and then left them behind to be found, as well as science can spawn anger in some of you that are less articulate then dirt.
Sorry all, I'm just playing fundie's advocate, as it were. I hope this isn't lost on you. I intend no offence!!
coeur Newbie First Class
Joined: Apr 13, 2008
Posts: 28
Posted:
Tue Apr 15, 2008 11:59 pm
(translated from french article)
"Paris, October 21, 2004
Our ancestors fish
Thanks to the sequencing of the genome of the fish Tetraodon nigroviridis, an international consortium coordinated by the group of Jean Weissenbach (CNRS-Genoscope) reveals the structure of the genome of the ancestor common to the man and fish, probably made up of only 12 chromosomes. These results are published in the nature magazine of October 21, 2004. They reveal moreover a duplication complete and very old, but posterior with separation fish/mammalian, genome of the ancestor of the fish, from which are resulting the near total from current fish.
Tetraodon nigroviridis is a small well-known fish of Southeast Asia of the aquarists, which has the effect of having the smallest genome known among the vertebrate ones. Although the human genome is eight times larger, the genes of the man and Tetraodon share great similarities of sequences. These characteristics, small size of the genome and homologies of sequence with the human genome, are at the origin of the choice of Tetraodon as model for the comparative analysis of the human genome by the team of Jean Weissenbach in Genoscope (Genopole® d' Evry).
Indeed, the similarities of sequences are a tool for the biologists, who know that the reasons preserved during the evolution generally correspond to genes. Thus, by comparing the sequence of two very distant animal organizations, they can recognize the sequences corresponding to genes in the middle of the enormous mass of “not signposted” information which the sequence of a genome of several million pairs of bases represents.
The first results of the sequencing of Tetraodon, started in 1997, had allowed, as of the year 2000, the researchers of Genoscope to estimate the number of human genes at 30.000 genes, whereas the majority of the estimates of the time even bordered exceeded 100.000. This result since was amply confirmed by the analyzes of the human genome.
The sequencing published this week in Nature by the international consortium, which includes/understands a big number of French groups associated with CNRS , covers approximately 90% of the genome of Tetraodon. For the first time in a fish, the majority of genes identified by sequencing were identified and located on the 21 chromosomes of Tetraodon. The researchers characterized genes which one thought absent in fish. They also could identify 900 new genes not yet identified at the man thanks to the comparison with the genome of Tetraodon.
The positioning of genes on the chromosomes of Tetraodon allowed, for the first time, to compare the chromosomal organization of the genomes of mammals and of fish, two lines whose last common ancestor lived at the Paléozoïque era, approximately 450 million years ago. The examination of genes of Tetraodon, initially within the genome then by comparison with human genes, indicates that the fish with radiated fins, i.e. the majority of the fish which we know today, duplicated their genome, this shortly after the separation of the two lines which will lead to fish and the mammals. “This evolutionary mechanism is well-known at the plants but it is very rare in the animals, and a fortiori at the vertebrate ones”, Jean Weissenbach comments. “Its consequences are very important because this mechanism confers on a species an important potential for the invention of new biological functions”.
By pairing the chromosomes duplicated at Tetraodon, the researchers could reconstitute the structure of the genome of the ancestor of fish with radiated fins. They thus discovered that the genome of this species now disappeared comprised 12 chromosomes and was probably also very compact. “This genome resembles that of modern Tetraodon much, which is surprising taking into account the hundreds of million years past between the two species”, Jean Weissenbach indicates. “On the other hand for the same period, the genome of the line which leads to the mankind underwent considerable rehandlings”.
This analysis of the genome of Tetraodon made it possible to the researchers of Genoscope to highlight the mosaic of the ancestral segments which compose the human genome, and to reveal part of the evolutionary history of the mankind since our last common ancestor with fish."
I've heard the snake's spurs explained as- get this- a remnant from when god cursed the devil (in "serpent" form) to crawl on his belly and eat the dust of the earth. Now, while most would agree that snakes don't eat dust, they do have vestigial legs.
So apparently, serpents had legs and were not called lizards by the ancient Hebrews. Good to know.
VESTIGIAL organs have long been a source of perplexity and irritation for doctors and of fascination for the rest of us. In 1893, a German anatomist named Robert Wiedersheim drew up a list of 86 human "vestiges", organs "formerly of greater physiological significance than at present". Over the years, the list grew, then shrank again. Today, no one can remember the score. It has even been suggested that the term is obsolete, useful only as a reflection of the anatomical knowledge of the day. In fact, these days many biologists are extremely wary of talking about vestigial organs at all.
This may be because the subject has become a battlefield for creationists and the intelligent design lobby, who argue that none of the items on Wiedersheim's original list are now considered vestigial, so there is no need to invoke evolution to explain how they lost their original functions. While they are right to question the status of some organs that were formerly considered vestiges, denying the concept altogether flies in the face of the biological facts. While most biologists prefer to steer clear of what they see as a political debate, Gerd Müller a theoretical biologist from the University of Vienna, Austria, is fighting a rearguard action to bring the concept back into the scientific arena. "Vestigiality is an important biological phenomenon," he says.
Part of the problem, says Müller, is semantic: people have come to think of vestigial organs as useless, which is not what Wiedersheim said. In an attempt to clear up the confusion, he has come up with a more explicit definition: vestigial structures are largely or entirely functionless as far as their original roles are concerned - though they may retain lesser functions or develop minor new ones. Müller points out that it is useful to know if a given structure is vestigial, both for taxonomic purposes - understanding how different species are related to one another - and for medical reasons, as in the case of an organ that has no obvious use in adults but turns out to be crucial in development.
Nobody doubts that some human structures that were once considered vestigial have proved to be far from redundant in the light of growing medical knowledge. For example, Wiedersheim's original list included such eminently useful structures as the three smallest toes and the valves in veins that prevent blood from flowing backwards. It also contained several organs we now know to be part of the immune system, such as the adenoids and tonsils, lymphatic tissues that produce antibodies, and the thymus gland in the upper chest, which is important for the production and maturation of T-lymphocytes.
Some of Wiedersheim's vestiges have since been identified as hormone-secreting glands - notably the pituitary at the base of the brain, which regulates homeostasis, and the pineal located deep in the brain, which secretes the hormone melatonin. Melatonin is best known for synchronising the activity of our internal organs, including the reproductive organs, with the diurnal and seasonal cycles, but it is also a potent antioxidant that protects the brain and other tissues from damage, so slowing down the ageing process.
Why men have nipples
Then there is the male nipple. The most showily useless of all human structures would seem to be a dead cert for continued inclusion on Wiedersheim's list. However, evolutionary biologist Andrew Simons of Carleton University in Ottawa, Canada, says any claim that it is vestigial is bogus. To be vestigial, an organ or something from which it is derived must have had a function in the first place. "There is no reason to believe that male nipples ever served any function," says Simons. Instead, they persist because all human fetuses share the same basic genetic blueprint and males retain a feature that is useful in females because there is no adaptive cost in doing so.
Natural selection shapes living organisms to survive, Müller points out. Once their survival is ensured, the organism may very well retain non-adaptive or non-functional features, provided they are not a burden. This is one reason why we shouldn't expect anatomical structures to be perfectly adapted to their function (or lack of one), says Simons. It also complicates the identification of truly vestigial structures.
Another problem arises when trying to show that a modern structure has lost function with respect to its ancestral form. Take the appendix, a small worm-like pouch that protrudes from the cecum of the large intestine. It was long thought to be a shrivelled-up remnant of some larger digestive organ - primarily because it is a lot less prominent than its counterpart in rabbits, with which it had previously been compared. In 1980, G. B. D. Scott of London's Royal Free Hospital put that assumption to the test. He compared the appendix in different primate species and found the human appendix to be among the largest and most structurally distinct from the cecum. "It develops progressively in the higher primates to culminate in the fully developed organ seen in the gorilla and man," he wrote.
Scott concluded that the appendix is far from functionless in apes and humans. Recent evidence from another quarter seems to support his finding. A study published last year in the Journal of Theoretical Biology (vol 249, p 826) by a group at Duke University School of Medicine at Durham, North Carolina, led by R. Randal Bollinger, found that the human appendix acts as a "safe house" for helpful, commensal bacteria, providing them with a place to grow and, if necessary, enabling them to re-inoculate the gut should it lose its normal microbial inhabitants - for example, as a result of illness. Although people who have had their appendix removed seem to suffer no ill effects, team member Bill Parker points out that the operation is mainly performed in the developed world. "If you lived in a traditional culture, any time before 1800, or in a developing country where they don't have a sewer systems, you are going to need your appendix," he says. Parker suspects that far from being vestigial, the specialised appendix evolved out of a cecum that had the more general twin functions of housing good bacteria and aiding digestion.
That would explain Scott's finding. However, there is an alternative explanation that allows for the possibility that the appendix is a vestigial organ. Ten years ago evolutionary theorists Randolph Nesse of the University of Michigan and George Williams, of the State University of New York at Stony Brook argued that while you might expect natural selection to eliminate the annoying human appendix if it could, we might paradoxically be stuck with it (Scientific American, vol 279, p 86). They pointed out that a smaller, thinner appendix would be more likely to become blocked by inflammation and inaccessible to a cleansing blood supply, increasing the risk of life-threatening infections. "Larger appendices are thus actually selected for," they concluded, even though they may no longer have a role.
The jury is still out on the human appendix, but examples from other animals leave no doubt that vestigiality is a real phenomenon. Look no further than wings in flightless birds for an unequivocal example of a vestige, says palaeontologist Gareth Dyke of University College Dublin in Ireland. The loss of flight in large, ground-living birds happened relatively recently - within the past 50 million years - usually as a result of the birds being restricted to an island, or because of the loss of terrestrial predators. The ostrich is an extreme case, because its wings have already lost some of the bones that were present in its airborne ancestors. "The feathers too are really modified," Dyke says. "They are not flight feathers any more. There's no structure to them. They are just really fluffy, downy feathers."
So, with the benefit of modern scientific knowledge, what are the most convincing examples of vestigial structures in humans? The New Scientist top-five list (see below) runs as follows: the vomeronasal organ, goose bumps, Darwin's point, the tail bone and wisdom teeth. There are undoubtedly more, however. It depends how wide you cast your net, says Müller. Some blood vessels have become reduced in size and function over time, and thinking smaller still, there must be chemical messengers and genes that qualify.
As evolutionary biologist Stephen Jay Gould pointed out, nobody ever said evolution was perfect. The existence of something as spectacularly de trop as the ostrich wing is only a problem for those who believe in an intelligent designer. On the other hand, the list of vestigial organs should still be considered a work in progress. Anything that appears to be entirely without function is suspicious, says Müller, and probably just waiting to be assigned one. Whether we are talking about useless vestiges or anatomical structures that have taken on a new lease of life, however, it is hard to ignore the evidence that human beings are walking records of their evolutionary past.
New Scientist's top five human vestiges
THE VOMERONASAL ORGAN
Rodents and other mammals secrete chemical signals called pheromones that carry information about their gender or reproductive state, and influence the behaviour of others. Pheromones are detected by a specialised sensory system, the vomeronasal organ (VNO), which consists of a pair of structures that nestle in the nasal lining or the roof of the mouth. Although most adult humans have something resembling a VNO in their nose, neuroscientist Michael Meredith of Florida State University in Tallahassee has no hesitation in dismissing it as a remnant.
"If you look at the anatomy of the structure, you don't see any cells that look like the sensory cells in other mammalian VNOs," he says. "You don't see any nerve fibres connecting the organ to the brain." He also points to genetic evidence that the human VNO is non-functional. Virtually all the genes that encode its cell-surface receptors - the molecules that bind incoming chemical signals, triggering an electrical response in the cell - are pseudogenes, and inactive.
So what about the puzzling evidence that humans respond to some pheromones? Larry Katz and a team at Duke University, North Carolina, have found that as well as the VNO, the main olfactory system in mice also responds to pheromones. If that is the case in humans too then it is possible that we may still secrete pheromones to influence the behaviour of others without using a VNO to detect them.
GOOSE BUMPS
Though goose bumps are a reflex rather than a permanent anatomical structure, they are widely considered to be vestigial in humans. The pilomotor reflex, to give them one of their technical names, occurs when the tiny muscle at the base of a hair follicle contracts, pulling the hair upright. In birds or mammals with feathers, fur or spines, this creates a layer of insulating warm air in a cold snap, or a reason for a predator to think twice before attacking. But human hair is so puny that it is incapable of either of these functions.
Goose bumps in humans may, however, have taken on a minor new role. Like flushing, another thermoregulatory mechanism, they have become linked with emotional responses - notably fear, rage or the pleasure, say, of listening to beautiful music. This could serve as a signal to others. It may also heighten emotional reactions: there is some evidence, for instance, that a music-induced frisson causes changes of activity in the brain that are associated with pleasure.
DARWIN'S POINT
Around the sixth week of gestation, six swellings of tissue called the hillocks of Hiss arise around the area that will form the ear canal. These eventually coalesce to form the outer ear. Darwin's point, or tubercle, is a minor malformation of the junction of the fourth and fifth hillocks of Hiss. It is found in a substantial minority of people and takes the form of a cartilaginous node or bump on the rim of their outer ear, which is thought to be the vestige of a joint that allowed the top part of the ancestral ear to swivel or flop down over the opening to the ear.
Technically considered a congenital defect, Darwin's point does no harm and is surgically removed for cosmetic reasons only. However, the genetics behind it tells an interesting tale, says plastic surgeon Anthony Sclafani of the New York Eye and Ear Infirmary in New York City. The trait is passed on according to an autosomal dominant pattern, meaning that a child need only inherit one copy of the gene responsible to have Darwin's point. That suggests that at one time it was useful. However, it also has variable penetration, meaning that you won't necessarily have the trait even if you inherit the gene. "The variable penetration reflects the fact that it is no longer advantageous," Sclafani says.
THE TAIL BONE
A structure that is the object of reduced evolutionary pressure can, within limits, take on different forms. As a result, one of the telltale signs of a vestige is variability. A good example is the human coccyx, a vestige of the mammalian tail, which has taken on a modified function, notably as an anchor point for the muscles that hold the anus in place. The human coccyx is normally composed of four rudimentary vertebrae fused into a single bone. "But it's amazing how much variability there is at this spot," says Patrick Foye, director of the Coccyx Pain Service at New Jersey Medical School in Newark. Whereas babies born with six fingers or toes are rare, he says, the coccyx can and often does consist of anything from three to five bony segments. What's more, there are more than 100 medical reports of babies born with tails. This atavism arises if the signal that normally stops the process of vertebrate elongation during embryonic development fails to activate on time.
WISDOM TEETH
Most primates have wisdom teeth (the third molars) but a few species, including marmosets and tamarins, have none. "These are probably evolutionary dwarfs," says anthropologist Peter Lucas of George Washington University, Washington DC. He suggests that when the body size of mammals reduces rapidly their jaws become too small to house all their teeth, and overcrowding eventually results in selection for fewer or smaller teeth (International Congress Series, vol 1296, p 74). This seems to be happening in Homo sapiens.
Robert Corruccini of Southern Illinois University in Carbondale, says the problem of overcrowding has been exacerbated in humans in the past four centuries as our diet has become softer and more processed. With less wear on molars, jaw space is at an even higher premium, "so the third molars, the last teeth to erupt, run out of space to erupt", he says. Not only are impacted wisdom teeth becoming more common, perhaps as many as 35 per cent of people have no wisdom teeth at all, suggesting that we may be on an evolutionary trajectory to losing them altogether.
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