Genomics and Human Identity: Lesson 2
In Genomics and Human Identity, Lesson 1 introduced four easily observed human traits and their variations and identified differences between the DNA sequences of two individuals. Lesson 2, another free classroom resource, takes grades 9 through 12 students further into the human genome – and into the dark world of shark attacks and forensic analysis.
In late August 2010, two men from a boat marooned in the Bahamas disappeared while attempting to swim ashore. Several days later, fishermen in the area caught a tiger shark containing human remains: But whose remains were they? Forensic scientists soon identified them by comparing DNA from the remains with DNA from relatives of each missing man.
Materials for Lesson 2 include a narrative of the events, figures and tables explaining the data obtained by forensic scientists, and supplementary PowerPoint slides. Well-structured questions lead students through the findings to show how DNA analysis established the victim’s identity.
Starting with the narrative, the handouts progress through a figure showing 16 genetic loci obtained from one individual, and another figure listing the numerous variations found at each locus in the general population: specifically, differences between individuals in how many times a short DNA sequence is repeated.
Another table displays the number of repeats at each locus in DNA from the victim’s remains. The same table shows the number of repeats at each locus for two children of one missing man, and for the mother and half-brother of the other missing man. Step-by-step questions guide students through the logical progression from analyzing forensic data to identifying the remains. The PowerPoint slides simplify class presentations and are designed to stimulate classroom discussions about the data and possible interpretations.
This lesson portrays the practical use of genomic analysis, without emphasizing socially complex (and potentially distracting) issues such as paternity testing, birth defects, criminal profiling, etc. The lesson is structured in a way that encourages students to think logically and fully understand each step of the process before reaching their conclusion. For students who approach STEM classes groaning “What would anybody ever use this for?” this exercise answers that question, and then some. A whiff of the Bahamas and a hefty dose of mystery also add pizzazz to the genomic information presented in this exercise.
Lesson 1 of the Human Identity Lesson Plan series is available as a free download at https://unlockinglifescode.org/education-resource-profile/genomics-and-human-identity
About the Creator:
This inquiry-based lesson on Genomics and Human Identity is the second in a series created by the National Human Genome Research Institute, supported by the Promega Corporation, and inspired by the Smithsonian National Museum of Natural History exhibit Genome: Unlocking Life’s Code. NHGRI is developing these resources to expand genome research beyond the exhibit into classrooms and other learning venues.