This document discusses vestigial structures as remnants of organs or characteristics that were once functionally important for ancestral organisms but have reduced or lost importance in present-day organisms. It provides examples of vestigial structures in humans like the tailbone and wisdom teeth. It also discusses how vestigial structures provide evidence for evolution by showing common ancestry between related species through homologous structures that have varied over time. Finally, it lists some vestigial structures found in other animals like whales, moles, and flightless birds.

1. Vestigial
Characteristics
Group 42
Ricky Baker
Kimberly Melara
Jay Paulson
Jessica Perry
Jamie Thomas

2. What Are Vestigial
Structures?
“Leftovers”
A structure of marginal importance to an
organism
Historical Remnants that once had important
functions in ancestors

3. How Do Vestigial Structures
Relate to Evolution?
Evidence for Evolution
Homology: shows a common ancestry
between related organisms
Closely related species = closely related
features
Homologous Structures: Represent Variations
of structural themes present in common
ancestors
Unlikely that such similarities will appear by
“chance” in different species

4. Examples of Vestigial Structures
in Humans
The coccyx, or tailbone(a
remnant of a lost tail) has lost its
original function in assisting
balance and mobility
Wisdom teeth are vestigial third
molars that human ancestors used
to help in grinding down plant
tissue to compensate for a lack of
ability to efficiently digest cellulose

5. Other Vestigial Characteristics in
Humans
Erector Pili, which form
goosebumps under stress.
The function was to raise the
body's hair, making one
appear larger to scare off
predators.
The ability to wiggle one's
ears
Used by ancestors to turn
their ears toward sounds.

6. Vestigial Structures in Other
Animals
Baleen whales have very small,
unformed hind legs that were
most likely used to walk on
land.
Blind Mole Rats have tiny eyes
that are covered by a thin
layer of skin, rendering the
eyes useless
The Emu, Ostrich, Cassowary
and Penguin are all
incapable of flight yet they
have wings.

7. Bibliograph
y
Cooper, Rachele. "Why Do We Have Wisdom Teeth? » Scienceline." Scienceline. 5
Feb. 2007. Web. 11 Oct. 2010.
Culluphid, Oolon. "The Human Coccyx and Appendix: A Study in Vestigiality." Oolon
Colluphid's Guide to Creation. 2007. Web. 11 Oct. 2010.
Spinney, Laura. "Five Things Humans No Longer Need." New Scientist. 19 May
2008. Web. 11 Oct. 2010.
"Top 10 Useless Limbs (and Other Vestigial Organs) | LiveScience." LiveScience |
Science, Technology, Health & Environmental News. Web. 12 Oct. 2010.
"Vestigiality." Wikipedia, the Free Encyclopedia. Web. 12 Oct. 2010.