To engage cohorts of life science students, we have designed a mock-up experiment about the parallel evolution of humans and dogs. This experiment is presented at the beginning of the semester in an introductory genetic laboratory course. We reasoned that an experiment involving dogs would foster interpersonal interactions and provide a framework for reviewing basic laboratory skills, learning a quantification technique (enzyme-linked immunosorbent assay or ELISA), and integrating core concepts in genetics and evolution. In this case study, students perform an indirect ELISA and measure amylase in simulated samples allegedly obtained from Gray Wolves (Canis lupus) and 8 dog breeds. Dogs have been living with humans for thousand years and may share evolutionary traits with us. Here, we focus on a dietary trait, the digestion of starch by amylase. In humans, production of salivary ??-amylase is high and associated with the duplication of the gene AMY1 that encodes ??-amylase. Humans possess variable numbers of AMY1 gene: populations that have adopted high-starch diet for a long time have high AMY1 copy numbers, whereas populations that have been living on low-starch diet (hunter-gatherers) have on average low AMY1 copy numbers. Since dogs have been exposed to human???s diets for a long time, would they also display the same evolutionary pattern? To answer this question, students measure the concentration of amylase in pancreatic juices of unknown canids using ELISA and standard curve calibration. Once data are validated, students obtain sample information and pool their data to increase sample size. Students then test if the positive association between AMY copy number and amylase production is present in dogs like in humans.
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