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Post by Tiger on Aug 23, 2009 13:01:38 GMT -5
That means it lost its original function, in this case that was to break down plant matter that we can no longer digest. So it used to house bacteria that digested cellulose? Why would we lose something like that?
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Post by yojetak on Aug 23, 2009 13:06:18 GMT -5
That means it lost its original function, in this case that was to break down plant matter that we can no longer digest. So it used to house bacteria that digested cellulose? Why would we lose something like that? Because meat is easier to digest.
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Post by Caitshidhe on Aug 23, 2009 13:50:21 GMT -5
*sighs* Just as the fundies cherry-pick their bible for things that defend or condemn whatever it is they support or dislike themselves--and discard whatever they find inconvenient (Leveticus springs to mind...)--they will cherry-pick science and technology for things that they find convenient for their own agendas and disregard or dismiss anything that contradicts their cherry-picked holy book. Which, in fact, is most of it.
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Post by ironbite on Aug 23, 2009 15:18:24 GMT -5
Even though the appendix houses some good bacteria....IT STILL HOUSES BACTERIA! Which, if I remember correctly, likes to make organs swell.
Ironbite-Vene correct me cause I'm pretty sure I'm wrong.
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Post by secularskeptic on Aug 23, 2009 15:18:58 GMT -5
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Post by Vene on Aug 23, 2009 15:25:16 GMT -5
That means it lost its original function, in this case that was to break down plant matter that we can no longer digest. So it used to house bacteria that digested cellulose? Why would we lose something like that? Because the loss of function didn't change the fitness of our ancestors and, likely, genetic drift was responsible for its loss. Genetic drift is the aspect of evolution where when traits don't alter survivability they can be gained or lost, it's completely random. But that doesn't mean it won't have effects on their ancestors. Remember, mutations are random, and at times the selection of traits can be random. Even though the appendix houses some good bacteria....IT STILL HOUSES BACTERIA! Which, if I remember correctly, likes to make organs swell. Ironbite-Vene correct me cause I'm pretty sure I'm wrong. Nah, housing bacteria is fine, our guts hold all kinds of them anyways and it's good that they have them. We have something like 100 trillion bacteria cell in our intestines. It's when pathogenic bacteria infect the appendix that there's a problem. They grow uncontrollably and that's when there's inflammation and bad things happen. Bad things like death. We really don't need the appendix, the cost of having it is currently greater than any benefit it provides.
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Post by ironbite on Aug 23, 2009 15:33:05 GMT -5
I WAS CORRECTED!
Ironbite-also...can bacteria go bad and also lead to them infecting the appendix and causing death?
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Post by Jedi Knight on Aug 23, 2009 15:43:55 GMT -5
...PZ is right, as usual. Someone writes an article with the title "Darwin was wrong!", which blows it out of proportions and makes the article seem very important. In this case, Darwin was wrong about a minor detail. Suddenly, the creationists interpret it as "Darwin was wrong altogether!" and have something to fap over.
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Post by catanon on Aug 23, 2009 16:48:11 GMT -5
...PZ is right, as usual. Someone writes an article with the title "Darwin was wrong!", which blows it out of proportions and makes the article seem very important. In this case, Darwin was wrong about a minor detail. Suddenly, the creationists interpret it as "Darwin was wrong altogether!" and have something to fap over. They're projecting. Their mindset with the bible is that it has to either be all right or all wrong. They're projecting that mindset onto Darwin, thinking that if a single little thing is incorrect, then his entire theory is bunk. Of course, that's entirely false, but don't tell them that or they'll get all defensive.
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Post by yojetak on Aug 23, 2009 17:42:28 GMT -5
I WAS CORRECTED! Ironbite-also...can bacteria go bad and also lead to them infecting the appendix and causing death? I was listening to a TED talk and the woman was a bacteria specialist. She said that mass wise, we're only 10 percent human and 90 percent bacteria. If you compared DNA, we're only 1 percent human. Ewwww.
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Post by Vene on Aug 23, 2009 18:50:15 GMT -5
I WAS CORRECTED! Ironbite-also...can bacteria go bad and also lead to them infecting the appendix and causing death? Yes and no. There are a lot of bacteria that are simply harmless, but others that can become very dangerous if there are too many of them. For example, Clostridium difficile is typically found in the intestines, but when the levels of bacteria get out of whack, they can overpopulate and cause disease. But, this isn't them infecting the appendix as much as it is having too many of them.
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Post by Tiger on Aug 23, 2009 19:13:49 GMT -5
So it used to house bacteria that digested cellulose? Why would we lose something like that? Because the loss of function didn't change the fitness of our ancestors and, likely, genetic drift was responsible for its loss. Genetic drift is the aspect of evolution where when traits don't alter survivability they can be gained or lost, it's completely random. But that doesn't mean it won't have effects on their ancestors. But the ability to digest grass would still be very useful in times of famine, even if meat is better. It doesn't seem like the trait would be actively disadvantageous, since housing bacteria doesn't take up much if any energy. Actually, how would you have housing bacteria in your genome? Maybe there wasn't any genetic change at all, the bacteria just moved out after grasses stopped being a major part of our diet?
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Post by Vene on Aug 23, 2009 19:40:57 GMT -5
Um, the change wasn't bacteria in our genome, those are called mitochondria and they have their own DNA. The change was the appendix itself, it's nearly nonexistant now, in herbivores it's another tract, similar to our intestines. But, you seem to think for some reason a trait has to be disadvantageous to be lost. This is not true. If it was we also wouldn't have a broken gene for making vitamin c.
That's why I mentioned genetic drift, it is random, it can do good and bad. Just, only so much and when the species isn't living off of cellulose, the organ can be lost.
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Post by Deimos on Aug 23, 2009 19:46:43 GMT -5
Quote from Scrubs
If this hospital were a human body, you'd be the appendix because at one time you served some function, but it was so long ago nobody's quite sure what that was anymore." Dr. Cox to Dr. Kelso
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tempus
Full Member
Alien Ant Farmer
Posts: 212
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Post by tempus on Aug 23, 2009 19:50:24 GMT -5
www.rr-bb.com/showthread.php?t=105791Apparently, Darwin was wrong when he said the appendix was left over from our ancestors, and it has no function. That's like saying Frankenstein isn't a good book because it has a typo. Sure, it has a function. "Vestigial" doesn't necessarily mean "useless." The appendix can store bacterial to repopulate the gut in the event gut flora are knocked out, and in countries where diarrhea is a frequent cause of death, that may be useful from time to time. It has a somewhat minor role in the function of the immune system. But these are not necessary or essential functions in most people. A few people are actually born without an appendix, and never feel the lack of one. In all the annals of medical science, there are no reports of people whose immune function and/or the proper functioning of the digestive system has been compromised by its removal. Nor has anyone ever died from the lack of an appendix, as far as anyone knows. In fact, losing it is frequently more beneficial than ever having one in the first place--it's primary purpose now seems to be to keep abdominal surgeons gainfully employed, by swelling up and occasionally exploding. The appendix is a good example of a mostly-unneeded organ that has been partially repurposed, but is still something of a hindrance that will eventually be lost. Rather than disproving evolution, it actually shows descent with modification to be still at work in our own species.
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