UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
Home
How it Works
Ask a Question
Search Topics
Webcasts
Our Scientists
Science Links
Contact Information
Why do humans have fingers and toes? Are their scientific name phalanges?
Answer 1:

The quick answer is that we have fingers and toes because our ancestors have them and because they are useful for walking and grapping objects.

The earliest land animals that moved out of water and onto land had various numbers of toes (and/or fingers) which they needed to support their weight. Over time, the five toed creatures established the ancestral (primitive) pattern for all land dwelling vertebrates.

Humans belong to the group called primates, a group of animals that was initially adapted to living in trees. Our body design is determined by our evolutionary ancestry. All primates have 5 fingers on each hand. The first finger is actually called a thumb. The thumb is separated from the other fingers. This allows the thumb to be brought into opposition with the other fingers. An opposable thumb improves the ability of primates to securely grasp objects in their hands. It also enabled us and other primates to develop tools.We have toes because our ancestors had toes. Human toes have become shorter and more adapted to running on the ground. This adaptation was of advantage because running on the ground was more important to the early human than was climbing in the trees.

The bones in the finger are called phalanges. Fingers 2-4 are made up of three phalanges; the thumb has two phalanges.


Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2015 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use