One Species, Many Vegetables – An Introduction to Artificial Selection

Brassica oleracea – An introduction to artificial selection

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A photo of Romanesco (also called Veronica) growing in our garden, just one of the many varieties of Brassica olereacea that thrive here in interior Alaska.

Subject area: Biological Science – 6-8th grade

Season: Best in early fall when Brussels sprouts attached to stem would be available and whole plants could be brought into classroom. Could be taught any time of year using vegetables from the grocery store.

Time: This lesson is a one class period introduction to the concept of artificial selection.

Suggested Materials: Samples of vegetables. Ideally these would include broccoli, Brussel sprouts, cabbage, cauliflower, collard greens, kale, kohlrabi and romanesco.  If possible it would be good to also bring in whole plants that would show where on the plant the different vegetables are located and how they relate to each other.

Other materials Data Collection handout,  Presentation.

Objective – Examine broccoli, romanesco, kale, kohlrabi, cauliflower, cabbage and Brussels sprouts to observe how traits of a single ancestor have been adapted to create very different vegetables. In the process students will also learn about the different parts of plants and how they grow.

State Standards:

State standards

Lesson Sequence – this lesson would be part of a unit on evolution that would include the concepts of both natural and artificial selection. Students would already be familiar with the way that traits are passed down from generation to generation by genes.

Activity:

*Students begin by working in small groups, observing vegetables provided by teacher. Observations and reflections are recorded on data sheet provided by teacher.
*After completing the activity, students share and discuss their observations.
*Teacher shares that these vegetables are all really a single species, Brassica oleracea.
*Present and discuss Presentation
*After viewing presentation, students again examine plants and continue discussion.
*This introduction to artificial selection would be followed by lessons on genetics and how both artificial and natural selection take place.
Extensions: Students could create a dichotomous key to the different Brassica oleracea varieties.
Cross-curricular connections –
Social Studies: Students could research the places where different Brassica oleracea varieties were domesticated, the roles that these vegetables play in different cultures, and other Brassica oleracea varieties that we are not familiar with in this country. This could culminate with a classroom Brassica oleracea feast.
Writing: Students could write and collate a recipe book for varieties of Brassica oleracea. This could culminate with a classroom Brassica oleracea feast. (Writing standard for grade 6: 2. Write informative/explanatory texts to examine a topic and convey ideas, concepts, and information through the selection, organization, and analysis of relevant content.

References
*Brassica oleracea. (n.d.). Retrieved June 20, 2016, from https://en.wikipedia.org/wiki/Brassica_oleracea
Source for some basic information on artificial selection of Brassica oleracea as well as some of the images in the presentation.
*Broccoli flower. (2011, February 5). Retrieved June 20, 2016, from http://bloominthyme.com/tag/broccoli-flower/
Source for broccoli flower image in presentation
*Defining a species. (n.d.). Retrieved June 20, 2016, from http://evolution.berkeley.edu/evolibrary/article/evo_41
One definition of “species” in presentation came from here.
*Definition of species in English:. (n.d.). Retrieved June 20, 2016, from http://www.oxforddictionaries.com     /us/definition/american_english/species
One definition of “species” used in presentation came from here.
*The Magical Brassica oleracea Plant. (2013, September 11). Retrieved June 20, 2016, from http://kottke.org/13/09/the-magical-brassica-oleracea-plant
Source for image showing adaptation of structures in different varieties of Brassica oleracea
*Osnas, J. L. (2012, November 05). The extraordinary diversity of Brassica oleracea. Retrieved June 20, 2016, from https://botanistinthekitchen.wordpress.com/2012/11/05/the-extraordinary-diversity-of-brassica-oleracea/
Source for some information on the artificial selection of different Brassica oleracea varieties.
*Reconstructing the Evolution of Cauliflower and Broccoli. (n.d.). Retrieved June 20, 2016, from http://serc.carleton.edu/genomics/units/cauliflower.html
Source for basic information on artificial selection of Brassica oleracea as well as some images in the presentation.
*Standards. (n.d.). Retrieved June 20, 2016, from https://education.alaska.gov/standards/
Source for Alaska State Standards

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