I have frequently struggled to help students connect the events of meiosis with the adaptive value of sexual reproduction; it’s hard to get students to look away from the stages of meiosis to see the “big picture” of genetic variability.
So I was interested to read a recent article by Dorit Eliyahu in The American Biology Teacher (full reference below). Eliyahu’s exercise leads students through a simulation of meiosis and reproduction in a fictional “reptilobird,” using paper chromosomes. Each student is issued a set of six chromosomes, including two pairs of autosomes and a pair of sex chromosomes. Each chromosome has 4 to 11 gene loci. The alleles for each gene are marked, and a key is provided for seven of the genes. For those seven genes, students can infer a reptilobird’s phenotype from its genotype.
I immediately liked that the students actually “do” crossing over between homologous chromosomes, at points that the students choose themselves. Already I saw an improvement over my own lab exercise, which uses paper chromosome cutouts but ignores crossing over.
The best part was yet to come, though. The students use their chromosomes to make gametes, then use those gametes to make and describe a baby reptilobird. In my current lab exercise students make a baby and characterize its features too, but the Eliyahu exercise goes one step farther. Students actually draw their reptilobirds and tape them to the board, so the whole class can see the variation that meiosis produces. Genius! As a bonus, the exercise incorporates clever questions that reinforce ideas of Mendelian genetics, codominance, incomplete dominance, sex linkage, gene linkage, epistasis, and pleiotropy. Bravo!
I tried this exercise for the first time, along with my husband/colleague Doug Gaffin, in his class Action Center a couple of weeks ago. About 35 students participated. It worked extremely well, with one exception: Students took a lot of artistic liberties with their reptilobirds. That turned out to be a problem, because a lot of the variation among the drawings came from the feather shapes, body colors, rainbows, and other decorations that were not specified in the instructions. (The photo at the top of this post reveals a small sample of our students’ artistic talents.)
We therefore decided to improve the process by adding a bank of cutout “reptilobird parts” for students to color and tape onto their reptilobird bodies, which should standardize the offspring phenotypes a bit more. We also changed the function of one gene: The X-linked phenotype of “color blindness” is impossible to draw onto the reptilobird body, so we changed that character to “beak color.”

Bank of cut-out reptilobird body parts. Note that the paper is printed in black and white, so the object colors are not relevant.
The article in The American Biology Teacher clearly lays out the instructions for the exercise, and Eliyahu’s handouts are freely available. However, I made some modifications to incorporate the “body part” bank and to adjust the content of the handouts to better suit our class needs; I also created a modified list of materials to assemble before each class. Please contact me via the comments section of this blog if you would like me to send my revised materials to you.
In the meantime, thank you to Dorit Eliyahu! We will definitely be chasing baby reptilobirds around the lab next fall.
Reference: Eliyahu, Dorit. 2014. “Chromoseratops meiosus”: A simple, two-phase exercise to represent the connection between meiosis and increased genetic diversity. The American Biology Teacher 76 (1): 53-56.
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Update, 10/14/14: We used the reptilobird activity for the first time in last week’s lab. As you can see from the photo at right, they were much more consistent in format, making it much easier to see the variation among the birds. This photo shows some of the birds scattered on the floor. In the classroom, however, my TAs arranged the four birds that corresponded to the four possible parental phenotypes along the top of the bulletin board. The students pinned their own birds below. The huge number of offspring phenotypes were a great illustration of the potential variation that comes from meiosis.
Only one thing was missing: an easy way to tell male from female. The next time we do this activity, the sheet with the reptilobird body will sport two new additions: large male and female symbols, which students can color in to indicate the sex of their bird. Other than that, I am very satisfied with this activity and can highly recommend it as a way to connect meiosis with genetic variation and natural selection.
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Update 2, 10/19/15: We did this lab again last week, and we made an important discovery. We thought it would be a good idea to save student time by having our undergraduate assistant cut out all of the chromosomes ahead of time and deliver them to students in coin envelopes. BIG MISTAKE! The students no longer understood what was homologous to what, mass confusion ensued, and the activity did not go well. Things went much better in the next lab session, when students had to cut out their own chromosomes as usual.
Also, if you want to incorporate an evolutionary connection into this activity, check out my followup blog post from June 2015.
Hi, I’d really love a copy of your modifications to Dr. Eliyahu’s activity: tdalyengel@uwf.edu. Thanks!
Thanks for asking! I’ve just sent them to you.
I plan to use this activity with my students soon. I would appreciate a copy of your “body part” bank. Thanks!
They are on their way!
I would also appreciate a copy of your modified materials. Thanks!
Thanks for responding; I just emailed them to you.
Wow, just what I’ve been looking for!! Could I have a copy of your modified parts? Thanks, Julie
Ha ha, I’m glad to be of service! I just emailed them your way.
I’d love to have access to your updates. Thank you!
Thanks for asking — I just sent them off to you.
I really like the standardized body parts – brilliant. Would you send me a copy when you have time? kfuller@lowercolumbia.edu Thanks, Katrina
Absolutely! They’re on their way.
Marielle, Would love a copy of your modifications. I teach Developmental Biology to upper level bio majors but they still have trouble with meiosis. I have been using a pipe cleaner exercise to demonstrate but this sounds like more fun!
Karen
I think it will be more fun than the pipe cleaners — good luck with it! I just emailed you my modifications.
Hi Marielle, Please send me the modified versions and Thanks so much for sharing this activity. My problem with teaching meiosis is they think they already know it from high school and so bring lots of misconceptions. I do like the follow up sheet showing all the genetics. Excellent. Thanks, Vera
They are on their way. I hope the activity works for you!
I would also love to have a copy of your modifications to this exercise. Thanks!
No problem! I just sent them to you.
I’d like a copy of the modified materials. Thank you for sharing with us!
They are on their way — sorry I missed this comment until today.
I found this activity while searching for options for the meiosis lab I’ll be teaching next week. I liked this activity so much I subscribed to your blog as well. Could you send me a copy of the modifications you made? Great ideas here!
I’m sorry I didn’t see this comment until now. I have just sent you the modifications and hope they are still useful to you.
I’m always looking for better activities. Thank you in advance for sending the modifications!
So sorry for the delay; they are on their way!
I’d also love a copy! I pan on doing this activity as soon as possible!
They’re on their way!
I would like to try this with my AP Bio students this year. Would love a copy of your modifications to the activity.
Hi Pam, I’d be happy to send it along, but I don’t see your email address. Can you please send it to me at hoefnagels@ou.edu? I’ll reply with the modifications.
I would love to have a copy of your revised documents. This is exactly what I want to drive home to my nonmajor Biology students, and is a perfect way to visualize the effects of genetic variation on phenotype! Thank you for offering your materials!! bbalazsi@fairfield.edu
They are on their way — I hope it works for you!
Hello! I would appreciate having a copy of your modifications! Thank you very, very much!
You are very welcome. They are on their way!
I’d love to do this activity with my non-majors this winter and would appreciate a copy of your modifications. Thank you!
I just emailed them to you. Good luck with the activity! I’d love to hear how it goes for you.
What a great exercise! If you are still offering your modifcations, I’d love a copy. Thanks!
I just emailed them to you. Enjoy!
Thanks for sharing this and the update. I’d love to have a copy of your modified materials for my class in Fall. Thank you.
They are on their way. I hope they work for you!
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Could you send me a copy as well? Looks like a great activity!
You bet! They’re on their way.
I’m hoping to incorporate this activity into my nonmajors course this fall. Could you please send me a copy of your modified materials? Thanks!
No problem! I hope it works for you.
Yet another request for your activity — it sounds great!
I will send them to you this morning. Enjoy!
Could I please receive a copy of your activity? Thank you!
You bet! I’ll email the materials shortly.
Could I please have a copy as well. Thank you for your ideas.
Tom Peri at perit@notredameprep.com
Certainly! I will send it along soon.
thanks a lot for sharing your experiences! I would like to try this activity with my class, and would really appreciate if you could send me your updated materials.
thanks a lot for sharing! could you send me your updated materials?
Sure! They’ll be on their way soon.
thank you for sharing! could you please send me your updated materials?
You bet! You should receive them soon.
This looks like a great activity. Can you please send me a copy of your updated materials? Thanks!!!
You bet! It’s on its way.
I feel like I’m late to the game, here, but I would love to have a copy of your updated materials. I can’t wait to try this activity. Thank you!
kforgey@shschools.org
Better late than never! I will send them to you right away.
May I please have a copy of your revised materials? Thank you for sharing!
I am so sorry for the delay! I will send them out to you shortly.
Hi! I am searching literature on meiosis for a book chapter I intend to write. I came across the Chromoseratops meiosus activity, and latter, to your modifications. I would like to include both parts in my classes for students teachers. Could you mail me a copy of your materials?
Thanks from Argentina, Norma
Certainly! I will send it to you in an email shortly.
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Your write up on “Antibiotic-Resistant Bacteria” left me wanting more 🙂 I would greatly appreciate a copy of your updated materials. This would be a perfect activity for a non-majors genetic course I will be teaching aboard. Thanks!
Hi Stephanie,
I will be emailing it to you shortly. Thanks for your interest!
Marielle
Thank you for your thoughtful post about this activity! This reptilobird activity, along with your modified antibiotic resistance activity, seem like a great starting point for some activities I’d like to use in my own course. Would you please email me a copy of these two activities? Thank you for sharing!
You bet! They will be on their way soon.
Hi I was hoping to get the modified portion of the activity. Thank you so much for your help with this! Best, Jeff Collins
You’re welcome! I just emailed you the materials.
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Hi, I’d really love a copy of your modifications to Dr. Eliyahu’s Reptilobird activity: TFITZPAT@depaul.edu. Thank you very much.
Sure, no problem! I will send you an email shortly.
Hello! This seems like a great activity! I wonder if it is too advanced for a high school class. We don’t really cover pleiotropy or gene linkage. Are these a big part of the lesson? And would you mind sending your body parts bank? chardin@crispschools.org Thank you!
Hi Courtney, thanks for your comment! It would be very easy to take out the questions about the traits related to pleiotropy and gene linkage; there are only a couple. I will send you all of the materials shortly.
Thanks for all of the feedback on this activity. If possible, please send me the body part banks so I coulld give it a try. Much thanks in advance
You bet! I’ll email them to you shortly.
Please send me your revised documents with body part banks. Thanks so much. abdrabl@dearbornschools.org
You bet! I’ll send them to you right away.
I would love a revised copy of this lab! It sounds great!
I will send them to you very shortly!
Thanks so much for sharing all of your tips and tricks! Could I have a copy of your materials for this lab please?
Absolutely! I’ll send it right out.
Could I please get a copy of your modified materials? Thank you.
I just sent them your way.
May I have a copy of your modified materials? I’m so happy to have found your blog! Thanks for sharing!
I’m so glad you’re finding the site helpful! I will email you the materials in a few minutes.