Download Evolution connection: proteins, carbohydrates, and nucleic acids

Evolution connection: proteins, carbohydrates, and nucleic acids
Learning goals:
Students will understand that 1) our evolutionary history has affected our genes and proteins, 2) the availability of
particular carbohydrates in the environment has shaped the evolutionary history of different human populations, and
3) our evolutionary history matters in our everyday lives.
For the instructor:
This short slide set weaves together basic information about carbohydrates, proteins, and nucleic acids into one
evolutionary story that relates to students’ everyday lives. To integrate it best, use these slides immediately after
you’ve discussed the structure of these biological molecules. You may wish to prime students for this story by
using lactose and lactase as examples when discussing carbohydrates and proteins. Additional details about the
translation of nucleic acids into proteins could be incorporated into the last slide of this series, to the degree that
you cover this material in your discussion of the structure of nucleic acids. You may also wish to return to this story
as an example when you cover Mendelian genetics. The European version of the lactase persistence gene is
inherited as a dominant Mendelian trait.
Each of the following slides comes with a sample script for the instructor. To review this script, download the
PowerPoint file and view the Notes associated with each slide.
Evolution Connection slideshows are provided by Understanding Evolution (understandingevolution.org) and are
copyright 2011 by The University of California Museum of Paleontology, Berkeley, and the Regents of the University
of California. Feel free to use and modify this presentation for educational purposes.
Evolution connection: proteins, carbohydrates, and nucleic acids
Digesting lactose with an enzyme
Lactose
Galactose
Glucose
Evolution connection: proteins, carbohydrates, and nucleic acids
Lactose
Lactase to the rescue!
Galactose
Glucose
Lactase image is from BioMolecular Explorer 3D and is used under the conditions of a
Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.
Evolution connection: proteins, carbohydrates, and nucleic acids
Gene for
lactase
Evolution connection: proteins, carbohydrates, and nucleic acids
10,000 years ago:
Lactose tolerance
100% lactose intolerant
arises and increases
in frequency.
Lactose tolerance
arises several times
and increases in
frequency.
Photo of highland cattle is by the Scottish government and is used under the conditions of a
Creative Commons license. Photo of Masai with cattle is by Oxfam International and is used
under the conditions of a Creative Commons license.
Evolution connection: proteins, carbohydrates, and nucleic acids
1. Ancestral lactose
control gene on
chromosome 2
lactose intolerance
2. C nucleotide replaced
by a T nucleotide
lactose tolerance
3. One of three single
nucleotide changes
lactose tolerance
Milkshake photo by Svadilfari and used under a Creative Commons license.
Reference:
Tishkoff, S. A., Reed, F. A., Ranciaro, A., Voight, B. F., Babbitt, C. C., Silverman, J. S.
. . . Deloukas, P. (2006). Convergent adaptation of human lactase persistence in
Africa and Europe. Nature Genetics. 39: 31-10.
Evolution Connection slideshows are provided by Understanding Evolution
(understandingevolution.org) and are copyright 2011 by The University of California
Museum of Paleontology, Berkeley, and the Regents of the University of California.
Feel free to use and modify this presentation for educational purposes.