Monthly Archives: September 2014

158 – Evolutionary Forces and Symbiosis

Today in honors biology we started just reviewing symbiosis since this is a concept kids learn in 7th grade. I implored them to get a tubular bird feeder this winter and layer different sized seeds to encourage competition. They seemed really into that. But, they really were interested in the brood parasite Cuckoo Bird.

We transitioned to a refutation exercise essay project where kids would refute the idea that all interactions between organisms results in competition. The kids paired up and sending them a peer edited document via Google Drive was a snap.

In AP biology we journeyed down the path to Hardy-Weinberg EQ via a discussion of evolutionary forces. Paul Andersen’s 5 Fingers of Evolution is really cool although it does leave out Genetic Drift.

Genetic drift is the hardest concept for my kids to get each year. The idea of a random series of events changing allele frequencies over time causes some skeptical reactions. Mostly, I think this is because of the way it is presented through figures and graphs. Maybe I am confusing also.

Tomorrow both classes have quizzes so a post will be boring, but I will post the quizzes for the SBG folks who want a look.

159 – Beavers and Catch Up Lecture

Today in honors biology we discussed the keystone species. Primarily, we focused on the beaver. In Scotland, after being extinct for 400 years they decided to introduce a small population. The organization responsible published some educational materials in advance to help kids get on board. One of those activities is a nice card matching game. Cards of organisms are paired up with the written statement about how the beaver interacts with the ecosystem. I really like this activity for a number of reasons: it only lasts 10 minutes, the informational cards allow for discussion of keystone species and niche, and kids really like it. Niche is often a hard concept for kids to master. By having the informational cards, kid can develop an idea of what the biotic “role” of the organism is. It would be a nice activity for next year, having kids choose an organism and develop their own cards. 

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In AP biology, I am going to catch up a bit on content with a 20/10/20 pattern of lecture, formative check, lecture. My goal this year was to lecture less, but there will be times when I have to do it for complicated topics or when I get behind. In those cases, my goal is to limit any lecture chunk to 20 minutes without some sort of active, processing break. 

The break I will use to day comes from a series of probes I developed using Far Side cartoons. I selected specific biology related Far Side cartoons (with Gary Larson’s blessing) and used them as a way to analyze specific performance indicators or learning objectives. 

This is an easy 10 minute break kids can work on after a topic has been introduced. 

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160 – Serengeti CER and the Snickers Bar of the Desert

Today in honors biology we took a simple pencil/paper activity and used it to do a Claim, Evidence, Reasoning (CER). The kids were using the activity as an assessment for one of their learning objectives. I had already used Doctopus to send them a template for their Google drive for the final copy. In class, they were to collaborate and work together to answer the questions about the activity which described multiple herbivores visiting the Serengeti, effectively following the rains and partitioning the niche unbeknownst to each other. During the work time, they were to complete the explanation tool for the CER. They were given the essential question “How do herbivores interact with each other on the Serengeti?” They were to create a claim to answer the question, pull out evidence form the data, tie classroom science to each piece of evidence, and write a reasoning statement that supported the claim, with the evidence and backed by science. In 15 minutes they actually did really well. The hardest part is backing the evidence up with our classroom science. Synthesis is hard for them since they are very literal beings right now. 

In AP biology we used our second model organism, the Rock Pocket Mouse, to study the effects of a selective pressure (visual predators) on the coat color phenotypes present in the population on tan desert terrain, and black lava flows. The students were given 4 pictures with two terrains (tan and black) and in each there were a number of mice. They were to sequence the pictures in a way that made evolutionary sense. They then watched one of the best 15 minute educational films made for biology, concerning the natural selection of the Rock Pocket Mouse (nicknamed the “Snickers bar of the desert”). High drama. 

The students were to think about how a random mutation (dark coloration), was a selective advantage in some environmental circumstances and a detriment in others. When it was an advantage, they had to think about how a mutation like this would spread rapidly in the population in a short period of time, while in the non-adaptive terrain it was selected against. They also had to ponder the idea of convergence on a specific phenotype since other, unrelated, Rock Pocket Mouse populations distally to these had similar mutations caused by different mutated genes. 

Tomorrow the honors kids will learn about the beaver as a keystone species through a card sorting game and the AP kids get a nice, old fashioned lecture, broken up by some short activities. 

 

161 – Niche and the Evolution of Paper Airplanes

Today in honors biology I taught for about 25 minutes on niche and habitat. Kids had a lot of questions. One that has come up before is the economics of being a Giant Panda in 2014. Their niche is so narrow and the kids struggle with the question of whether they would exist without human help. 

Fundamental niche and realized niche as well as niche partitioning are always tough to teach. I had them start an activity using data of 3 migratory Serengeti herbivores, as they track the rains and eat grass of varying length. They were perceptive to the idea that the animals were partitioning the niche without even being in the same place at the same time. 

In AP biology, we just ended our discussion of natural selection using Grant’s finches as our model. Today we created our own bird models using straws and paper to test the evolution of design by “mutating” various “offspring” of the parent plane. Students were to fly three offspring and the one with the best mutation would survive and be the next parent. Mutations were determined by coin flips and die rolls. It was fun and a nice break from the data crunching we have been doing. Tomorrow we will analyze the results for selection trends. 

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162- Biogeochemical Cycle Evacuation Drills

Today was my first day back from a two school day hiatus. Of course, the day had its challenges. Mainly, a evacuation drill during my AP bio class. Challenge met, but only for 20 minutes. 

Today in honors biology we discussed the major biogeochemical cycles. Mostly probing question and answer. My biggest goal was to connect the larger, global cycle to what happens inside a cell, and then bridge the two with food chains. Basically, how do the global cycles matter to living things? We did this for the carbon, nitrogen and phosphorus cycles, with the focus on organic molecules and how the transfer is made via food chains. 

In AP biology, a reflection on the Grant Galapagos finch data revealed some nice talking points regarding the students’ take away of natural selection. I am using the 40 year Grant finch study to model natural selection. The data is great and I think students see clearly how natural selection can happen quickly under the right circumstances. 

Tomorrow in honors we will finally build the Winogradsky columns and in AP work on the Evolution in Action activity continuing the finch data exploration.