Serendip is an independent site partnering with faculty at multiple colleges and universities around the world. Happy exploring!

Change Over Time: Making Sense of the Diversity of Life

Wil Franklin's picture



Photos of Us Searching for Homologies of Ourselves

What do you see?





Organism Puzzle


Squirrel/Sugar Glider


Guinness Video - Devolution




Continental Changes


To use Jeff Cohen's heuristic metaphor: What would the world look like if you were a very observant mole

that popped up every few hundred, thousand years?

Precambrian - only aquatic simple cells - 750-590mya





Cambrian - Diversity Explosion (life still aquatic) - 590-500mya






Ordovician - First Land Plants - 500-440mya








Carboniferous - Fern and Conifer Jungle & Age of Amphibians - 360-286mya









Cretaceous - Final Days of Dinosours - 144-65mya



To use another Jeff Cohen heuristic tool, Life as we know it today is a palimpsest on the thin biosphere veneer of the earth. Further, some of what we see today is poking through from ancient times.


Bones, Homology and Phylogeny

Photos of Us Conducting this Search







Anne Dalke's picture

Looking for Homologies

Just want to be sure you don't miss all the great images of us looking for homologies--I just love the way our faces echo the bones we are analyzing!
Diane OFee-Powers's picture


I loved the classification activity! It fits right into the 7th grade curriculum. The stations were very interesting also, it is a great way to teach problem solving and cooperative learning. The tree activity is another activity I can take back to  my science class. It is another example of teaching the kids to anyalyze the information  presented  and learning how to apply the informaion to solve the problem. I think I would introduce one tree at a time and discussed  why the right answer made more sense than the other 2 choices.
Mary Ellen McGinnity's picture

Diversity of Life

The activities were highly effective for me because Wil and Anne have created an atmosphere in which we could use our own background knowledge base, bounce ideas off each other, and have the time to process what we were experiencing through trial and error. Having the opportunity to hear other ideas/opinions enables students to process their own understanding of a topic, and engages them in a higher level of thinking. This is inquiry learning at its finest!


RecycleJack Marine's picture

Diversity of Life

Incredible presentation for a biologist! You make me think about how the organisms developed and how they are interconnected too. If I asked my students to sort the Organisms Puzzle, I think there would be catagories like organisms in different colors, and sizes. The diversity of life on Earh is overwhelming, but it is also deliberate. Everything is here for a specific reason, and with extinction of species due to Global Warming and environmental change we may be altering this deliberateness.
Rosemary Krygowski's picture

Change is the Only Certainty

    Wil's workshop today was very helpful in linking the past to the present. I was totally engaged as we went through the various activities. The biggest problem was to stay in class because my mind wandered back to school and how I would adapt the activites to my classes this fall.

Anne's comment about looking for similarites was very poignant. When I did yesterday's activities my observations only made sense when the other group shared their data with us.I think that finding similarities is a safe starting place. It is through recognizing our similarites that it becomes easier to accept our differences.

Benjamin Zerante's picture

Morning Response

I think this morning was an amazingly useful and informative presentation. I have studied evolution theory many times in the past and even taught it several times now. Wil's presentation this morning and the activities we did in the lab just made something in my head click though. It was so amazing to look at the actual physcial structures of different organisms and try to compare the similarities and then draw conclusions about relationships and evolution. This morning really showed me that nothing compares to hands on learning. I have seen pictures in books and read explanataions before, but until there was an actual horse and cow leg in front of me, it just wasn't as real or applicable for me.
Patricia Mundy's picture

Diversity of Life

I thought it was very interesting to see how diverse the organization of the pictures were placed in groups around the classroom. I hesitated participating in the activity, because I wasn't sure I was following the directions correctly.Later, I realized after each person explained why their pictures were positioned in a particular way, there was no right or wrong classification. I have learned I am a product of teaching that has incapacitated my (creative flow). I must be mindful of how I communicate with my students ,so they will not be afraid of exploring and discovering the world.
Rosemary Krygowski's picture

Creative Flow

I feel that many of us were taught in this same environment and it has been beneficial to recognize  the universal fear of incorrect answers . I also want   to create a safe environmentin my classroom where everyone wants to contribute. I also found that a focal point of this institute.
Judith Lucas-Odom's picture

What I Saw

Today's session was exciting, mind-boggling, hands-on, dynamic and fun! I enjoyed the activities because they engaged not only my curiosity, my conscious, and my unconscious mind but also my body. Everything worked together to create a story that I would enjoy re-enacting with my students! Thanks Wil!

Also, I wanted to encourage Ashley. You have all the great qualities of an excellent teacher. Keep using the energy and skill God gave you and He will see you through all things! Excellent presentation!

Rita Stevens's picture

Change Over Time or Similarities

Wil's workshop enabled you to see more similarities than seeing changes over time. Changes occurred primarily for adaptation purposes but most of the structures shared similarities. So, my question is Are species changing or adapting to survive? It really gets you thinking about another aspect of sense of place as well as self.
Anne Dalke's picture

Inquiry-based Science Education: "A Tough Road"

"When you get done playing all these games, when do you actually teach physics?"

Dora Wong, the Haverford College science librarian who joined us for our discussion of "inquiry-based education" on Friday, just forwarded me this article from The Chronicle of Higher Education: "The Tough Road to Better Science Teaching." It describes the wide-spread resistence, in the science departments of research universities, to just the sorts of inquiry-based teaching we've been exploring in this institute (typified in the quote above), and the responses to those critiques, based on findings from educational psychology and cognitive science.

Anne Dalke's picture

Change--or Persistence?

So--Wil called his workshop "Change over Time"--but we spent the morning looking for similarities, both in the first activity (when we organized our organisms) and in the second (when we went hunting for homologies). Why is it important to see the similarities? Is it really accurate to say that science is built around the search for what is similar, rather than a refined awareness of what is different?
Second question: he said that we can find two different explanations for these similarities--either response to environment or common descent. I'm thinking that "nature and nurture" or "genes and environment" are more closely linked and interactive than that. What makes us like one another is a complex interaction of both, not just one or the other...