How Did Horses Evolve?

A new study published in the peer-reviewed journal Science on February 10, 2017 is challenging long-held ideas about how horses evolved. Paleontologist Juan Cantalapiedra and team compiled decades of previous research into an evolutionary tree of 138 horse species (seven of which exist today), spanning roughly 18 million years. Continue reading

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What do lizards, finches, and fossils have in common? Dry Labs for Evolution

Curriculum Connection: Grade 11, Biology, Evolution

Teachers may find themselves in a bind when it comes to developing lab activities for the evolution unit in grade 11 biology. While working as a student teacher at Albert Campbell C.I., I strove to incorporate a series of creative and relevant evolutionary biology lab activities for my students to work on. The dry labs that I selected were both enjoyable and valuable to their learning.

At this point, you may be asking, “What do lizards, finches and fossils have in common?” Not only are they all connected to aspects of evolutionary biology, (biogeography, adaptive radiation, paleontology, phylogeny, etc.) they also play the starring roles in the following collection of dry labs.

Activity #1 Great Fossil Find

            The Great Fossil Find was a Nature of Science activity that required students to play the role of paleontologists as they “dug up” fossilized bones out of a paper envelop and attempted to reconstruct skeletons of ancient species. Students pulled out their cut-out bones and arranged them on their tables. With furrowed eyebrows and puzzled expressions, they realized how difficult it was to discern the identity of fossilized animals with incomplete fossil evidence. Despite their confused demeanour, they worked in pairs to try to identify the uncovered bones in reference to fossil handbooks they were given.

As students put together their skeletal puzzles, every “aha” moment was evident. From the moment a student discovered that the bone they found was not a hand bone, but actually a wing bone, to when they realized that they could identify their fossil even though the skull was missing, the piecing together of students’ knowledge of fossil evidence and their progressive understanding of the process by which scientists make sense of that evidence mirrored the piecing together of their fossils.

Activity #2 Anolis Lizards of the Greater Antilles

            Following a lesson on island biogeography, I asked my students to complete a dry lab on the evolution of the Anolis Lizards of the Greater Antilles. The activity involved a data table containing information on the characteristics of different species of lizards, their habitats, and their geographic locations. Using the data, my students cut out different lizards and pasted them on a map of the Greater Antilles. The students worked in pairs as they cut, pasted, and then observed patterns among lizards living on the same islands or in similar habitats. They did so by answering questions on the accompanying handout.

My students enjoyed working on this dry lab. Cutting and pasting the intricate little lizards served as a brief break from biology class. Moreover, students were prompted to apply their understanding of island biogeography, speciation, and adaptive radiation while investigating trait similarities and evolutionary relatedness between species. Finally, the activity allowed them to develop hypotheses based on their geographic arrangement of cut-out lizards and their analysis of patterns in traits.

Activity #3: Finch Beak Dry Lab

To further emphasize the struggle between members of the same species for limited resources and the influence of natural selection on population phenotypes, I had my students participate in a Darwin’s Finches dry lab. The lab was framed as a competition, with each student within a table group acting as a particular finch on the Galapagos Islands.

by Leila Knetsch

What do lizards, finches, and fossils have in common? Dry Labs for Evolution

Author: Nathasha Dias.

Curriculum Connection: Grade 11, Biology, Evolution

Teachers may find themselves in a bind when it comes to developing lab activities for the evolution unit in grade 11 biology. While working as a student teacher at Albert Campbell C.I., I strove to incorporate a series of creative and relevant evolutionary biology lab activities for my students to work on. The dry labs that I selected were both enjoyable and valuable to their learning.

At this point, you may be asking, “What do lizards, finches, and fossils have in common?” Not only are they all connected to aspects of evolutionary biology (biogeography, adaptive radiation, paleontology, phylogeny, etc.), they also play the starring roles in the following collection of dry labs.

Activity #1: Great Fossil Find

            The Great Fossil Find was a Nature of Science activity that required students to play the role of paleontologists as they “dug up” fossilized bones out of a paper envelope and attempted to reconstruct skeletons of ancient species. Students pulled out their cut-out bones and arranged them on their tables. With furrowed eyebrows and puzzled expressions, they realized how difficult it was to discern the identity of fossilized animals with incomplete fossil evidence. Despite their confused demeanour, they worked in pairs to try to identify the uncovered bones in reference to fossil handbooks they were given.

As students put together their skeletal puzzles, every “aha” moment was evident. From the moment a student discovered that the bone they found was not a hand bone but actually a wing bone, to when they realized that they could identify their fossil even though the skull was missing, the piecing together of students’ knowledge of fossil evidence and their progressive understanding of the process by which scientists make sense of that evidence mirrored the piecing together of their fossils.

Activity #2: Anolis Lizards of the Greater Antilles

            Following a lesson on island biogeography, I asked my students to complete a dry lab on the evolution of the Anolis Lizards of the Greater Antilles. The activity involved a data table containing information on the characteristics of different species of lizards, their habitats, and their geographic locations. Using the data, my students cut out different lizards and pasted them on a map of the Greater Antilles. The students worked in pairs as they cut, pasted, and then observed patterns among lizards living on the same islands or in similar habitats. They did so by answering questions on the accompanying handout.

My students enjoyed working on this dry lab. Cutting and pasting the intricate little lizards served as a brief break from biology class. Moreover, students were prompted to apply their understanding of island biogeography, speciation, and adaptive radiation while investigating trait similarities and evolutionary relatedness between species. Finally, the activity allowed them to develop hypotheses based on their geographic arrangement of cut-out lizards and their analysis of patterns in traits.

Activity #3: Finch Beak Dry Lab

To further emphasize the struggle between members of the same species for limited resources and the influence of natural selection on population phenotypes, I had my students participate in a Darwin’s Finches dry lab. The lab was framed as a competition, with each student within a table group acting as a particular finch on the Galapagos Islands.

Finch beak dry lab

Students were equipped with different beak traits and competed with each other for limited numbers of food items, including paper clips, black beans, and Styrofoam puffs. I had not expected the competition to be so fierce! Aside from trying to grab as much food as possible, my students used a variety of cunning strategies, including stealing food from others and knocking on each other’s beaks, to gain access to the most resources. All in all, it was a hoot—or should I say…a tweet?

Different finch beaks

Activity #4: Hominoid Skulls Stations

To wrap up the evolution unit, I taught the topic of human evolution by giving students the opportunity to act as evolutionary biologists. Each table group constituted a station set up with a skull cast of one of the ancestors of Homo sapiens. Students circulated the classroom in their groups, handled the skulls, recorded their observations based on features of each skull, and ultimately developed a dichotomous key.

Hominoid skulls stations

Students were immediately intrigued by the skulls stations upon entering the classroom. I had set up envelopes with measuring equipment for each group. Students handled calipers for the first time as they made measurements. Many were astonished at some of the features of early human skulls. Others marvelled at similarities skulls of modern humans share with some of our earliest known ancestors. This hands-on lab was a memorable way to end the unit.

Early human skulls

Hominoid skulls can be bought individually or in groups of seven. A set of seven can cost roughly $900, but individual skulls can be purchased for about $140 each. Contact your local science supplies distributor for more information.

References:

  1. http://www.indiana.edu/~ensiweb/lessons/gr.fs.fd.html
  2. http://www.ucmp.berkeley.edu/education/lessons/anolis.html
  3. http://www.teacherweb.com/nj/williamrsatzmiddleschool/mrsjflynn/Finch-Beak-Lab.docx
  4. https://view.officeapps.live.com/op/view.aspx?src=http%3A%2F%2Fwww.middletownhs.org%2Fourpages%2Fauto%2F2012%2F12%2F17%2F47604347%2FHOMINOID%2520SKULL%2520COMPARISON%2520Tchr%2520Guide.docx

Author: Nathasha Dias