- DNA to Darwin
- Classroom activity
Time: 2-3 hours
Students investigate the evolution of taste receptors by using protein sequence data to generate a phylogenetic tree of sweet, umami and bitter taste receptors from six animal species. In a second, more advanced activity, the evolution of bitter taste receptors by gene duplication is studied using DNA sequence data. The unusual case of the giant panda, which has lost the ability to taste meaty flavours, is also introduced.
- [History of life: Grades 13-16] Present-day species evolved from earlier species; the relatedness of organisms is the result of common ancestry.
- [History of life: Grades 13-16] Biological evolution accounts for diversity over long periods of time.
- [Evidence of evolution: Grades 13-16] Features sometimes acquire new functions through natural selection.
- [Evidence of evolution: Grades 13-16] The patterns of life's diversity through time provide evidence of evolution.
- [Evidence of evolution: Grades 13-16] An organism's features reflect its evolutionary history.
- [Evidence of evolution: Grades 13-16] There is a fit between organisms and their environments, though not always a perfect fit.
- [Mechanisms of evolution: Grades 13-16] Evolution results from natural selection acting upon genetic variation within a population.
- [Mechanisms of evolution: Grades 13-16] Traits that confer an advantage may persist in the population and are called adaptations.
- [Studying evolution: Grades 13-16] Scientists use multiple lines of evidence (including morphological, developmental, and molecular evidence) to infer the relatedness of taxa.
- [Studying evolution: Grades 13-16] Evolutionary trees (i.e., phylogenies or cladograms) portray hypotheses about evolutionary relationships.
- [Studying evolution: Grades 13-16] Evolutionary trees can be used to make inferences and predictions.
There are no NGSS/DCI concepts currently linked to this resource.
Be sure to test the free software used in this lab before attempting it with students. Some users have reported trouble, while others have had none. Also, be sure to fully test the activity yourself before using it. Some students may find the directions confusing. However, with a few clarifications, these activities are worthwhile.