This project was prepared as part of a BioQUEST faculty development workshop entitled BioQUEST Summer Workshop 2007 at Beloit College in June 2007. The BioQUEST Curriculum Consortium is committed to the reform of undergraduate biology instruction through an emphasis on engaging students in realistic scientific practices. This approach is sometimes characterized as an inquiry driven approach and is captured in BioQUEST's three P's (problem-posing, problem-solving, and peer-persuasion). As part of this workshop groups of faculty were encouraged to initiate innovative curricular projects. We are sharing these works in progress in the hope that they will stimulate further exploration, collaboration and development. Please see the following links for additional information:

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Click Clack - Milk Attack??
Authors          Audiences          Overview           Materials          Resources           Future Directions



Gretchen Koch
Goucher College

David Matlack
Earlham College

Paul Mangum
Midland College

Kristin Jenkins
Duke University


Possible Audiences:

Genetics, Biostatistics, Anthropology, Language studies  


Brief Overview:

Lactate persistence (also known as lactose tolerance) refers to adult expression of the lactase-phlorizin hydrolase (LPH) enzyme controlled by the LCT gene. The selection for this trait in the human population appears to be correlated with the domestication of cattle and utilization of milk. SNP linked alleles have been identified for European and African populations. The data set presented by Tishkoff et al. 2007 contained the genotype of the SNPs at 13907, 13915, and 14010 base pairs upstream from the LCT gene for 493 individuals. The data set further categorized each individual according to the country in which he or she resides as well as the language spoken. Based on the raw glucose rise after lactose digestion, each individual (for which measurements were available) was given a lactose tolerance phenotype. Those individuals that are lactose intolerant are Type 1; Type 2 individuals show a slight intolerance to lactose. Finally, individuals of Type 3 show a phenotype of lactose tolerance. The original research analyzed the data based on language spoken and country of origin. In contrast to the original paper, our analysis removed the geopolitical borders separating the sampled individuals and combined the samples as language groups. Alec Knight et al., 2003, used Y chromosome and mtDNA variation among African populations and concluded that the click (including Khoisan) languages are the most ancestral of the African languages groups.  


Project Materials:

Excel worksheet with dataset and macro code Google Lactose Demo kmz file requires Google Earth to be loaded on your computer.  


Resources and References:

Knight, Alec, et al. 2003. African Y Chromosome and mtDNA Divergence Provides Insight into the History of Click Languages. Current Biology, Volume 13, Issue 8, 15 April 2003, Page 705. Tishkoff, Sarah A, et al. 2007.Convergent adaptation of human lactase persistence in Africa and Europe. Nature Genetics, Volume 39, Number 1, Pages 31 40.