Exploring Our World

Do Our Textbooks Need to Be Accurate and Up to Date?

Subject: Vestigial Organs

“Vestigial organs are organs of the body which are smaller and simpler than those in related species. They have lost, or almost lost their original function. An unused organ usually degenerates and becomes smaller or vanishes altogether.”


Examples Given for Vestigial Organs:

1. Boa constrictors and pythons have tiny rear leg bones.

2. Whales have hind-limb bones left over from having legs.

3. The human appendix has no remaining function.

4. Humans have tail bones left over from when they had tails.

Vestigial Organs in Snakes?

Pelvic spurs in Boa Constrictors and Pythons Serve a Purpose.

It has been understood for over 30 years that these tiny claw-like structures near the base of the tail, are related to the snake’s sexual functions. The male actually uses them to sexually stimulate the female.

The Role of Pelvic Spurs – Raymond T. Hoser HERPTILE (UK), 10 (3), 1985, PAGE 95

They aren’t useless, and there is no evidence they used to be anything different than they are now.  Why are students still being taught they are useless and serve no purpose?

Vestigial Organs in Whales?

"...sometimes bones are present in an organism but are reduced in size and either have no use or have a less important function than they do in other, related organisms. Such structures, which are considered to be evidence of an organism's evolutionary past, are called vestigial structures. For example, the hind limbs of whales are vestigial structures." HOLT BIOLOGY - Holt, Rinehart and Winston, 2006, Pg. 286

Science Fact:

Those bones in whales are deeply embedded in muscle tissue, are not connected to the vertebral column, show no evidence they ever were, serve as a support to the pelvic wall, and also have muscle groups attached to them and serve as an organ anchor.  These whales cannot reproduce without them. See Science - July 1990.

Why are students still being taught these bones are useless and serve no purpose?

Vestigial Organs in Humans?

Human Appendix

Loren G. Martin, professor of physiology at Oklahoma State University, believes that early in development the appendix serves as an important function of the immune system.  He believes that the appendix "teaches" the immune system to distinguish dangerous pathogens from harmless food particles. Science Magazine

“During the early years of development, however, the appendix has been shown to function as a lymphoid organ, assisting with the maturation of B lymphocytes (one variety of white blood cell) and in the production of the class of antibodies known as immunoglobulin A (IgA) antibodies.” Scientific American – Oct. 21, 1999

Why are students still being taught these organs are useless and serve no purpose?

Human Tailbone

"Without the coccyx (the tailbone) and its attached muscle system, humans would need a radically different support system for their internal organs which would require numerous design changes in the human posterior, ..." Vestigial Organs are Fully Functional - By Dr. Jerry Bergman & Dr. George Howe

“Despite its small size, the coccyx has several important functions. Along with being the insertion site for multiple muscles, ligaments, and tendons, it also serves as one leg of the tripod—along with the ischial tuberosities—that provides weight-bearing support to a person in the seated position.”

National Library of Medicine – Spring 2014

Why are students still being taught the tailbone is useless and serves no purpose?