Making “Reptilobird” Babies: An Action Center Success Story

Sample birds

A selection of reptilobirds from Action Center.

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.”

Reptilobird body parts

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.


Reptilobird samples

A selection of reptilobird babies.

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.

Bird body with male/female

The latest modification to the reptilobird body, now with male and female indicators to color in.

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.


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.

This entry was posted in Active learning, Assignments, Collaboration, Engaging students, Evolution, Laboratory activities, Teaching and tagged , , , , , , , , . Bookmark the permalink.

98 Responses to Making “Reptilobird” Babies: An Action Center Success Story

  1. Toby says:

    Hi, I’d really love a copy of your modifications to Dr. Eliyahu’s activity: Thanks!

  2. Mary Rosenthal says:

    I plan to use this activity with my students soon. I would appreciate a copy of your “body part” bank. Thanks!

  3. Cynthia says:

    I would also appreciate a copy of your modified materials. Thanks!

  4. Julie Harless says:

    Wow, just what I’ve been looking for!! Could I have a copy of your modified parts? Thanks, Julie

  5. Jennifer Kneafsey says:

    I’d love to have access to your updates. Thank you!

  6. Katrina Fuller says:

    I really like the standardized body parts – brilliant. Would you send me a copy when you have time? Thanks, Katrina

  7. Dr. Karen Dorman says:

    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!

  8. Vera says:

    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

  9. Emily says:

    I would also love to have a copy of your modifications to this exercise. Thanks!

  10. Heather Scherr says:

    I’d like a copy of the modified materials. Thank you for sharing with us!

  11. 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!

  12. mleechen says:

    I’m always looking for better activities. Thank you in advance for sending the modifications!

  13. Laura says:

    I’d also love a copy! I pan on doing this activity as soon as possible!

  14. Pam says:

    I would like to try this with my AP Bio students this year. Would love a copy of your modifications to the activity.

  15. Bethann says:

    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!!

  16. Kelly Biddle says:

    Hello! I would appreciate having a copy of your modifications! Thank you very, very much!

  17. Pamela says:

    I’d love to do this activity with my non-majors this winter and would appreciate a copy of your modifications. Thank you!

  18. Jeremy says:

    What a great exercise! If you are still offering your modifcations, I’d love a copy. Thanks!

  19. Ching-Yu Huang says:

    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.

  20. Pingback: Reptilobirds revisited: An evolutionary connection | Teaching nonmajors biology

  21. jmlandin says:

    Could you send me a copy as well? Looks like a great activity!

  22. Tanya says:

    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!

  23. Karen Gerhart says:

    Yet another request for your activity — it sounds great!

  24. Chris B, says:

    Could I please receive a copy of your activity? Thank you!

  25. Tom Peri says:

    Could I please have a copy as well. Thank you for your ideas.

    Tom Peri at

  26. 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.

  27. thanks a lot for sharing! could you send me your updated materials?

  28. C. Roy says:

    thank you for sharing! could you please send me your updated materials?

  29. Kerry Valdez says:

    This looks like a great activity. Can you please send me a copy of your updated materials? Thanks!!!

  30. Kimberlie Forgey says:

    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!

  31. C. Slife says:

    May I please have a copy of your revised materials? Thank you for sharing!

  32. Norma Gonzalez says:

    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

  33. Pingback: Antibiotic-Resistant Bacteria: A Simple, Realistic Lab Activity | Teaching nonmajors biology

  34. Stephanie says:

    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!

  35. 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!

  36. Jeff Collins says:

    Hi I was hoping to get the modified portion of the activity. Thank you so much for your help with this! Best, Jeff Collins

  37. Pingback: Another Way to Connect Selection, Phenotype, and Genotype | Teaching nonmajors biology

  38. Terry Fitzpatrick says:

    Hi, I’d really love a copy of your modifications to Dr. Eliyahu’s Reptilobird activity: Thank you very much.

  39. Courtney H. says:

    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? 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.

  40. Nigel Laborde says:

    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

  41. Lena Abdrabbah says:

    Please send me your revised documents with body part banks. Thanks so much.

  42. I would love a revised copy of this lab! It sounds great!

  43. Melissa Graham says:

    Thanks so much for sharing all of your tips and tricks! Could I have a copy of your materials for this lab please?

  44. Dan Durr says:

    Could I please get a copy of your modified materials? Thank you.

  45. I just sent them your way.

  46. CY says:

    May I have a copy of your modified materials? I’m so happy to have found your blog! Thanks for sharing!

  47. Cassie says:

    This would be perfect for my students. They struggled with meiosis this year. I would love your modifications.

  48. Anne-Sylvie Crisinel says:

    Hi! I’d love to have your materials. Planning to do it with my students. Thanks!

  49. Joan McKearnan says:

    I also am interested in this lab. Can you send me materials? Thanks in advance.

  50. ajmaley says:

    These modifications look really neat and I’d love to use them. Would you be willing to share them with me? Thanks!

    (I apologize if this posts multiple times, I’ve been having some technical issues.)

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s