Happy Spring Break, everyone! I hope some of you were able to get out of town to somewhere warm. I certainly did not. As a Cubs fan, I can confidently say, maybe next year!
Events of the Past Week
Monday - We began our evolution unit by taking a look at how carbon dating works. The students worked toward completing an activity about the way in which radioactive dating works for most of the period. Homework was to work on their D. melanogaster reports.
Tuesday - We began class with a fifteen minute lecture on spontaneous generation, the age of the earth, and radioactive dating of rocks and fossils. This was followed up by completing the carbon dating activity from the day before, as well as completing an activity on the geologic time scale. When the students completed these activities, they could use any remaining time to work on their reports. Homework was to continue working on their D. melanogaster reports.
Wednesday - I was at an AP conference at Northwestern University, so the students watched a NOVA video called "Origins." This explained the conditions of primitive earth to the students, and also showed them some hypotheses as to how the first organic compounds may have been formed. Homework was to work on the D. melanogaster reports.
Thursday - The original plan was to learn about natural selection. However, this is the key concept in the evolution unit, and it appeared to me that the students were really nervous about their reports. They also seemed a little distracted by spring break approaching. As a result, I decided to give them the day to work on their reports, which they were all quite thankful for! Homework was to complete their D. melanogaster reports.
Friday - After turning in their reports and completing a peer evaluation form, where the students graded themselves and their partners on their effort on the project, we watched three short clips from the Howard Hughes Medical Institute showing three examples of evolution in action, where scientists can pinpoint when the adaptations in the organisms observed arose, and what genetic changes caused those adaptations to appear. Homework was to enjoy spring break!
Monday - The students will be introduced to the concepts of natural selection. After I lecture to them for a little bit, we will spend the rest of the class period doing an activity learning about the different ideas presented in the 1800's that tried to explain the mechanism of change in organisms over time. The ideas that we will be investigating were proposed by Charles Darwin, Alfred Russell Wallace, and Jean Baptiste Lamarck.
Tuesday - We will be doing a lab investigating natural selection using different types of dried beans (pinto, kidney, and lima). The students will investigate the change in their bean "population" over time. Homework will be to complete the questions in the lab.
Wednesday - Class will begin with the students getting an introduction to the evidence that supports evolution. When that is complete, we will begin a lab investigation looking at different vertebrate skeletons to investigate homologous and analogous structures. Your children should be able to explain the difference between those two types of structures when they come home on Wednesday night. Homework will be to complete the lab questions that go along with the investigation.
Thursday - We will investigate a second type of evidence that supports evolution on Thursday - biochemical evidence. This investigation will take a close look at amino acid sequences for the same protein in different organisms. The students will find that the more closely related two organisms are, the more similarities there are between their amino acid sequences. Homework will again be to complete the questions associated with this investigation.
Friday - We will be watching a NOVA video called "Great Transformations" on Friday. This video shows students the ways in which whales have changed over time, explains how tetrapods evolved, and looks at the genes that control the development of the embryo in organisms from Drosophila melanogaster (oh yeah!) to Homo sapiens.
Graba Geek of the Week
This week's geek of the week is Liz Flavin. She worked incredibly hard on her group's project, helping to keep everyone in her group on task with their parts of the project, and also taking on the task of writing the discussion and bottle analyses for the report. This is an incredibly important, time-consuming task. Liz really stepped up to be a leader in her group, which was very impressive. Way to go, Liz!