Notices
Results 1 to 14 of 14
Like Tree1Likes
  • 1 Post By icewendigo

Thread: The Appendix?

  1. #1 The Appendix? 
    New Member
    Join Date
    Jan 2012
    Posts
    2
    What use does the appendix actually provide?
    Many people i ask have said that it has no function, but this seems unusual, as why would something evolve in our bodies that is completely useless?
    any thoughts would be great


    Reply With Quote  
     

  2.  
     

  3. #2  
    Suspended
    Join Date
    Oct 2008
    Posts
    1,847
    It has some role in immune system function, and other digestive related stuff.

    The appendix did not necessarily evolve from nothing into its current roles and structure - it may very well be the ineradicable residue of a usefully functioning organ of some sort. The problem may be that getting rid of it completely in one step might be the only way - shrinking it increases, rather than decreases, its costs and risks (smaller appendixes get infected more easily). And one step major change is very unlikely.


    Reply With Quote  
     

  4. #3  
    Forum Bachelors Degree
    Join Date
    Jul 2008
    Posts
    420
    I think it's pretty much a vestigial organ.

    Tri~
    Reply With Quote  
     

  5. #4  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,840
    It has been postulated that the appendix today is a reservoir of beneficial bacteria. If most of our useful bugs are expelled by a terrible bout of diarrhoea, then the appendix seeds a new lot into our guts.

    This may or may not be true, and more research is needed. However, the origins of the appendix are clear. It is the vestigial remains of an organ (caecum plus appendix) that, in some of our early mammalian ancestors, which permitted digestion of cellulose.

    Humans today have a very small gut for our total size, compared to any other primate. Because we cook our food, digestion is easy, and we no longer need these digestive organs.

    It is also a possible interesting exercise in evolutionary theory. The appendix can lead to fatal appendicitis. So, without an overwhelmingly important function, why has evolution not removed it completely? The reason appears to be related to the effects of micro-evolution. If the appendix could be eliminated in one go, it would probably be an advantage. However, that is not how evolution works. Evolution operates by small incremental changes - not massive alterations. Thus, the appendix would have to evolve into smaller and smaller size before being lost.

    Some researchers have found that a smaller appendix actually increases the odds of getting appendicitis. A larger appendix is less likely to get blocked with an infection inside. Therefore, it is an advantage to have a larger appendix, instead of a smaller one, and evolution maintains an appendix of fair size.
    Reply With Quote  
     

  6. #5  
    Forum Bachelors Degree
    Join Date
    Jul 2008
    Posts
    420
    It is also a possible interesting exercise in evolutionary theory. The appendix can lead to fatal appendicitis. So, without an overwhelmingly important function, why has evolution not removed it completely? The reason appears to be related to the effects of micro-evolution. If the appendix could be eliminated in one go, it would probably be an advantage. However, that is not how evolution works. Evolution operates by small incremental changes - not massive alterations. Thus, the appendix would have to evolve into smaller and smaller size before being lost.
    Yep, and the right suite of mutations necessary for this to happen may well have never occurred, even if the potential selection pressure was present.
    Reply With Quote  
     

  7. #6  
    Suspended
    Join Date
    Nov 2011
    Posts
    276
    Quote Originally Posted by tridimity View Post
    I think it's pretty much a vestigial organ.

    Tri~
    Just curious. If it is a vestigial structure, what was its purpose in our ancestors? Doesn't seem as obvious as a tail bone :P
    Reply With Quote  
     

  8. #7  
    Forum Bachelors Degree
    Join Date
    Jul 2008
    Posts
    420
    I will answer one quote with another!

    Just curious. If it is a vestigial structure, what was its purpose in our ancestors? Doesn't seem as obvious as a tail bone :P
    Brody

    However, the origins of the appendix are clear. It is the vestigial remains of an organ (caecum plus appendix) that, in some of our early mammalian ancestors, which permitted digestion of cellulose.
    Skeptic
    Reply With Quote  
     

  9. #8  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,222
    Research tells us it's like having money in the bank. Only it's digestive bacteria rather than money. You only go and get it when you've overspent your normal allowance.
    Scientists discover true function of appendix organ - ABC News (Australian Broadcasting Corporation)
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  10. #9  
    Forum Freshman
    Join Date
    Feb 2012
    Location
    Montevideo, Uruguay
    Posts
    5
    The appendix produces and protects good germs for the gut and reboots it with good germs when others have been destroyed or expelled.
    Reply With Quote  
     

  11. #10  
    Forum Ph.D.
    Join Date
    Jul 2010
    Location
    Australia
    Posts
    792
    The stuff of which we are made is so multifunctional that for some part to be wholly functionless is exceptional.

    Appendicitis kills, but so does diarrhoea. If the appendix aids recovery after serious gut infections the overall balance may be more advantage than disadvantage and lead to, ultimately, greater reproductive success. Which is the true test of evolutionary 'fitness'.
    Reply With Quote  
     

  12. #11  
    Forum Cosmic Wizard icewendigo's Avatar
    Join Date
    Jun 2006
    Posts
    2,150
    I have a question that might be related.
    ~What is the survival of the fitest evolutionary advantage of having exactly 153 hairs in my left eye brow instead of 152 or 154?~
    tridimity likes this.
    Reply With Quote  
     

  13. #12  
    Forum Bachelors Degree
    Join Date
    Jul 2008
    Posts
    420
    Quote Originally Posted by icewendigo View Post
    I have a question that might be related.
    ~What is the survival of the fitest evolutionary advantage of having exactly 153 hairs in my left eye brow instead of 152 or 154?~
    LOL



    Tridimity~
    Reply With Quote  
     

  14. #13  
    Forum Ph.D.
    Join Date
    Jul 2011
    Posts
    984
    Gorillas, who look a lot like us, have very different guts. They have, I believe, a fully functioning Appendix as a additional stomach to handle their completly vegetarian diet. Digetively a Gorilla has much in common with a cow.
    Reply With Quote  
     

  15. #14  
    Time Lord
    Join Date
    Apr 2008
    Posts
    5,328
    Since we now appreciate the appendix's use, I think we need another metaphorically useless body part. The little toenail?
    A pong by any other name is still a pong. -williampinn
    Reply With Quote  
     

Similar Threads

  1. Appendix
    By verzen in forum Biology
    Replies: 2
    Last Post: March 26th, 2009, 01:31 PM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •