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Lab Dissections

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Jennifer Parr Jennifer Parr 10 Points

I want to do a dissection for my biology students, but I do not want to do it with a focus on anatomy. I want to do it with a focus on evolution. I think I may have to have the students complete two dissections. Does anyone have any ideas on this, or any lesson plans that they have used to teach evolution through dissection? Thanks!

Barbara Searcy Barbara Searcy 630 Points

 One way to do dissection in regard to Evolution  is to use a worm,  sea squirt, frog,  fish, baby shark, and an egg of a chicken. Ask students to brainstorm how they are related . Answers may vary but you want notochord, gills, seperate mouth and anus,  notochord  lays in  dorsal position and / or have  bilateral symetry and  a head. Which are or not vertebrates, chordates?  Let them try to place them on phlogenetic tree. If older students , they can access Gen/Bank to get genomes and use SeaView to view the tree design.  How  or what was needed to help animal adapt in its shape? More information can be found on NSTA evolution videos or check outfree Coursera class- Evolution for Teachers, Vertebrates, etc. Hope this helps.   You can check out NSTA  book- Evolution in Perspective  and Conferences- on making a dichotomous key, patterns. Use theory of  Darwin natural selection-to find  differences in fish- carp and salmon and shark, , show there are varieties of fish, use two types of amphibians- leopard frog and toad to show variantion by genetics, and survival of fittest.  ask questions-Are these animals similar to past extinct species on the tree? Let the student research the fossil record for frogs, fish etc.. 

Usha KelleyMaharaj Usha KelleyMaharaj 30 Points

Hi Jennifer, I changed my approach to dissections to shift it from basic anatomy to a comparative anatomy lab in order to move the focus to evolution and to emphasise HOTS. To do this students are assigned to one of the following specimens for their dissection (listed in order of easiest to most challenging to dissect): frog; fetal pig; pigeon; shark; turtle. I do not tell them how to dissect the organisms or which organs/structures to expect in their specimen. They divided into teams of 4. Each student has a primary role (on the spot researcher; photographer; 2 dissectors). Before the lab, they are required to research dissections of their specimen so they have an idea how to proceed and what they may expect to find. They are not penalized in my lab for "non-traditional" dissection techniques so long as they do a thorough job effectively documenting the internal organs and structures of their specimen (the head is not dissected unless kids have time and wish to do so). For their "lab report" they produce a PowerPoint presentation of their organisms. As a class we pool our data on the presence or absence of key synamorphies in our specimens and then try to determine their relative evolution times by placing these synamorphies on a phylogeny tree. I have to update the files I use for this lab this year, but I have attached last years version for you to checkout.

Casey Nolan Casey Nolan 20 Points

One important piece of evidence in evolution is the similarities among embryos of different organisms. Perhaps dissecting a chick embryo and comparing it to embryos of another organism (either by dissecting or looking at photos, such as of human embryos) you can present this idea in the context of evolution. Another option would be finding homologous structures in different organisms, and having the students label them themselves. Hope this helps!

Cheryl Ralph Cheryl Ralph 1570 Points

I think I would use various organisms and focus on the homologous structures. Point out to the students that we use organisms similar to us to help with medical research. Also if budget is a concern I would do the fetal pig and point out how the pig's heart is similar to our heart.

Laura Pokrajac Laura Turek 1820 Points

My science team is in the middle of developing ways to teach about the Evidence of Evolution. In it we include: Fossil Study Comparative Anatomy Study of Embryos DNA We are a Jr. High and were not sure how students would handle actually embryos - like chicks, so we found online resources. This is an online resource we have used for the embryo study.

Meg Griffith Meg Griffith 130 Points

There are a couple of things that come to mind. I think it might be a great way to teach about osmoregulation and the evolution of different systems to keep solute concentration in check. You can also do the differences in the circulatory system. You would probably need some larger specimens to see the excretory systems, but I think it might be totally worth it because you would be integrating some many important concepts. Dogfish shark, maybe frog (bullfrogs), and a fetal pig. I am actually loving this idea and would love to develop a kit that takes this approach. Contact me if you would like to talk more about it. Thanks, Meg Griffith Staff Biologist Flinn Scientific 1-800-452-1261

Rachelle Travis Rachelle Travis 1255 Points

Thanks for this question because I'm looking into doing this with my 8th graders at the moment. They've been begging to do disections but Evolution is the only way to make this fit into my scope and sequence. Some of the ideas given here are excellent and I'll be sure to use them!

I'm working on some lesson plans/worksheets for this as I type this. And I know this question was posted a while ago, but I'll post my final product as well so that other teachers can make use of this as a resource. 

Marie Gipson Marie Gipson 20 Points

Hi Rachelle! I was wondering if you had any resources you used to do this for your 8th graders! I would love to be able to look at what you did with them.

Rachelle Travis Rachelle Travis 1255 Points

Hi Marie!

I used the Carolina disection kits and chose organisms that were both least expensive and had something to compare to another organism being dissected. I'm attaching the Comparitive Anatomy worksheet that I created for the lab report. Note that in my case this was a summative activity and I wouldn't necessarily do it the same way again. I'd probably want it in the Explore section rather than as an extension next year.


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