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 GalactoseGlucose

Evolution connection: proteins, carbohydrates, and nucleic acids Lactase to the rescue! GalactoseGlucose Lactose 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 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. Lactose tolerance arises several times and increases in frequency. Lactose tolerance arises and increases in frequency. 10,000 years ago: 100% lactose intolerant

Milkshake photo by Svadilfari and used under a Creative Commons license. 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 Evolution connection: proteins, carbohydrates, and nucleic acids

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: 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.