“Vestigial or not vestigial” - that is the question?
Target Audience
AS Biology students who wish to extend their knowledge of the development of the human body and
evolutionary effects
Key Concepts
Vestigial organs, evolution, creationism, human body, male nipples
The Activity
Vestigial organs were once considered passé but now we have discovered important biological
functions and a need for every one of them. For this activity you are going to focus on one, once
considered vestigial, organ - the male nipple. Or is it vestigial? Does an organ that has never been
seen to have a function, classify as vestigial in evolutionary terms? Or could it have a physiological
role in the nurturing of offspring – ultimately sharing the parenting role?
Background Knowledge
It would be useful if you have a rudimentary knowledge of human anatomy and a basic understanding of
the concepts of evolution and creationism. A basic knowledge of the effect of hormones would also be
advantageous to tackle the specifics of this activity.
Resources
• In order to start your investigation into the existence of the male nipple, use this website for initial
ideas http://www3.telus.net/csabc/Vestigial.html
• To identify the similarities between male and female nipples this website has important facts
http://www.emedicine.com/plastic/TOPIC214.HTM
• For initial ideas and key words to search for the reasons behind why males have nipples try this site
https://notes.utk.edu/Bio/greenberg.nsf/0/0765bb50d404455385256f0000680854
Outcomes
Once you have gathered information from the selected sites and others you find yourself, prepare a table
of arguments for and against the reasons for the existence of the male nipple. Use this to inform a
presentation of your findings in whatever form you think appropriate.
Helpful hints
A large amount of ‘fact’ available on many websites comes down to interpretation, therefore, when you are
researching this topic be mindful of differing opinions and form yours by your own interpretation.
• What is considered to be a vestigial organ? Why is this theory being challenged in the modern world?
• Male and female embryos are the same at early stages of development. What causes a foetus to
develop male characteristics?
• Investigate the roles of Sex determination and male hormones in the development of maleness.
• Creation vs evolution view:- http://creationontheweb.com/content/view/5248
• Medical interpretation of the existence of male nipples:- http://anatomynotes.blogspot.com/2006/02/male-nipplesand-round-ligaments-of.html
Going further
Find out about the differing views on other organs in the mammalian body e.g. goose bumps, the
appendix or the pineal gland. There are many creationist websites where vestigial organs and evolution is
challenged, for example http://www.creationinthecrossfire.com/documents/VestigialOrgans/VestigialOrgans.html.