Expert: Dana Krempels, Ph.D. - 7/23/2008

Question
QUESTION:  Hi,
  Is it true that the human tailbone is vestigial? Are there any other parts that are vestigial?

ANSWER: Dear Amir,

A structure that is "vestigial" is simply one that had a use in an ancestral species, but is no longer obviously functional in the species you are observing.  The coccyx (tailbone) of the human (and other great apes) is an example.  In our close relatives, the tail bones are functional and help the animal maintain balance.  In great apes/humans, the tail has become reduced and no longer has any obvious function.

We have other structures that are somewhat vestigial, or at least have lost some of their ancestral function.  One example is the appendix.  In many primates and rodents, this performs important digestive functions.  In humans, this organ no longer contributes to digestion, but has some remaining immune system function.

Hope that helps.

Dana

---------- FOLLOW-UP ----------

QUESTION:  I'm sorry, that is not true. There are three muscles that connect to the tailbone. If you don't have the tailbone, you cannot perform a verry valuable function! I hope you figured out what it is!? And you are right about the appendix, it is part of the immune system but it has and had nothing to do with digestion. Therefore, there are no vestigial structures. Everything was DESIGNED to do something. Also, there is absolutely no evidence for evolution. It is a dumb religion and has nothing to do with science. PLEASE PUT IT IN THE RELIGION SECTION! Q: What is the evidence for evolution and WHY ARE YOU COMPARING HUMANS TO RODENTS AND APES?

ANSWER: Dear Amir,

Evolution is not a religion.  It is an observable phenomenon that we can witness happening today.  We can see the evidence for past evolution in the homologies of our own species and those of closely related species such as other primates and rodents.

The coccyx may have some very residual function, compared to what it does in vertebrates with a fully functional tail.  But the structure is still vestigial in comparison to that of the ancestral form.

You may not like to believe that you are descended from the same ancestor as other primates, but your simply saying "that is not true!" doesn't make evolution a falsehood.  It simply is a fact, and no fundamentalist religion is going to change that.

I could tell from your initial questions that you had a religious "agenda," but I still gave you the courtesy of a polite and educated answer.  If you are not willing to learn, then why did you write to me?  You are not going to convert me or make me abandon rational thought.  I am not going to go backwards to the level of an uneducated religious zealot simply because s/he tells me that what I know to be a fact is "not true."  Be serious.

This is not the place to seek religious converts, Amir.  This is a place to seek knowledge and learning.  I would suggest that if it is religion you seek, that you should go to a church, mosque, or synagogue--whichever you find appropriate for you.  Leave science and religion separate, as they must ever be.  

Science is the study of what can be observed and known for fact.  Religion takes up where that leaves off.  And that's that.

Sincerely,

Dana

---------- FOLLOW-UP ----------

QUESTION:  Hi,
  You said that there is evidence for evolution. What is it? Also you are trying to explain the origin of universe from the inside. It is just like asking: How did the computer form (And your answer cannot be intelligence or MAN which is outside the computer) How can you explain the existence of the computer?

Answer
Dear Amir,

If you are truly interested in learning about the evidence for evolution, then please go here for an excellent tutorial from the University of California at Berkeley Museum of Paleontology:

http://evolution.berkeley.edu/evolibrary/search/topicbrowse2.php?topic_id=46

It is an excellent, up-to-date site with all the most recent information.

Your computer analogy is broken, and I'm not going to try and fix it.  But please do help yourself to a big chunk of evolutionary education from the UCBMP.

Enjoy.

Dana