LEARNING ABOUT AGENTS OF MICROEVOLUTIONARY CHANGE IN A REMOTE ENVIRONMENT

This exercise is based on the activities described in
Lee, T.W., Grogan, K.E. and Liepkalns, J.S., 2017. Making evolution stick: using sticky notes to teach the mechanisms of evolutionary change. Evolution: Education and Outreach, 10(1), pp.1-13.
https://evolution-outreach.biomedcentral.com/articles/10.1186/s12052-017-0074-2
that I used for inspiration for some in-class activities in my BI111 Biological Diversity & Evolution Class. Since we've move to online tutorials, I have had to rethink how this can be done. These slides illustrate what I've come up with for this year.

Transcript

1. BI111: Biological Diversity & Evolution Tutorial 2: Population Genetics Exercise
2. Welcome to the “Stationary Islands”, an archipelago of land masses • Each research team (breakout room) will be spending a “field season” based on one pair of “islands” which consists of a large and a small island (the shapes below). These islands are home to members of “Stickies” a haploid species (which reproduces clonally). • Please makes sure you have downloaded this ppt file (and the Stickies_Data.ppt file for recording your data (there is also a copy on the next page), and that one person in each research shares this presentation on their screen.
3. SMALL ISLAND BIG ISLAND Generation Blue Pink Yellow Green Blue Pink Yellow Green 1 0 0 0 0 2 2 2 2 2 3 4 5 6 7
4. • In this species there are 4 possible haplotypes (and thus 4 phenotypes). Initially there are 2 “Stickies” individuals of each phenotype on the large island, and no “Stickies” on the small island. • Record the frequency of the initial phenotypes in your large island population (Generation 1) • You will now be sent off to your pair of islands with your research team! See you soon!
5. • (Remember that one person in each team should share their screen & do the manipulations described below & on the following slides) • An unusually low tide has revealed a (temporary) sandbar, allowing a few curious “Stickies” to migrate to the smaller island before the rising tide cuts them off. • The researcher who is sharing their screen should move (no more than 3) “Stickies” from the large island to the small island. • All “Stickies” will then reproduce clonally. (Select the organisms, copy & paste) • Record frequency of phenotypes on both the small and the large islands (Generation 2). • Copy all the stickies on the two islands and paste them on the blank island in the next slide
6. • Later in the season, favourable currents allows a handful of individuals to move from the large island to the small island (and vice versa). • Move (up to) 5 “Stickies” from one island to the other. • Once the migration between island is over, the “Stickies” will reproduce clonally (copy, then paste). • Record frequency of phenotypes on both the small and the large islands (Generation 3). • Copy all the stickies on the two islands and paste them on the blank island in the next slide
7. • Tragedy strikes again! A few unfortunate “Stickies” have perished before they had the chance to reproduce. • Without looking, remove 2 individuals from each island before a round of clonal reproduction (copy, then paste). Record frequencies of phenotypes (Generation 4) • Copy all the stickies on the two islands and paste them on the blank islands on the next slide
8. • Tragedy strikes again! A larger number of unfortunate “Stickies” have perished before they had the chance to reproduce. • Without looking, remove and additional 8 individuals from each island before a round of clonal reproduction (copy, then paste). • Record frequency of phenotypes on both the small and the large islands (Generation 5). • Copy all the stickies on the two islands and paste them on the blank island in the next slide
9. • A flying predator arises has arrived on the archipelago… and it’s hungry (& also a picky eater)! • Let one member of the team “fly” between the islands, predating on 10 (total) “Stickies” of their TWO favourite colours (use the annoation tool)! • After the predator has left, the surviving “Stickies” undergo a round of clonal reproduction (copy, then paste). • Record the frequency of phenotypes on both the small and the large islands (Generation 6). • Copy all the stickies on the two islands and paste them on the blank islands in the next slide
10. • It’s a (natural) disaster! A massive event of mass destruction (use your imagination) wipes out all but 10 “Stickies” on the island pair. • As a group (using the annotation stamp) remove all but 10 of your stickies based on an appropriate mortality rule (e.g. If it‘s a tsunami, higher mortality near one (or all) of the coasts, if it‘s a volcano, 1st to die are near the centre of island, if it‘s a meteor, closest to your site of impact, etc...). Decide how your 10 survivors will be distributed across the 2 islands. • Let all the surviving “Stickies” undergo one round of reproduction (copy, then paste). • Record the frequency of phenotypes on both the small and the large islands (Generation 7). • Take a screencap of the two islands • Wait to be returned to the main tutorial Zoom session (if you are bored of waiting, look ahead at the questions on the last page – you can start working on the 1st question)
11. Congratulations on the end of your field season! • Take a look at the final distribution of the phenotypes of “Stickies” on your big and small islands, and then once back in the main Zoom room look at (and take a screenshot of) the distribution of the “Stickies” on the other islands of the archipelago. • Now it’s time to write your end-of- season reports!
12. Before you leave the archipelago (i.e. the tutorial) please submit a report (each section ~1/2 page) to the dropbox • Describe what happened to each colour of “Stickies” over the course of the field season (on both islands), and how migration, genetic drift and/or selection each contributed to these evolutionary changes. What characteristics could have caused one phenotype to survive and/reproduce more than another phenotype? • How similar or different were your group’s results from those populations studied by the other teams? What conclusion(s) can you draw from this exercise regarding the repeatability of the effects of various “agents of micro-evolutionary change”, and their consequences to a species’ gene pool?