2/29

This week, we discussed other pieces of evidence that support the theory of evolution. We talked about the fossil record, geologic time scale, plate tectonics, and vestigial structures. In our lab, students practiced using relative fossil dating techniques to find the estimated age of different fossils. They had to arrange "rock samples" into order based on their fossil components. Students were also required to create a timeline of their fossil record after putting them into the correct order. We spent Thursday reviewing for our evolution test, and we took the test on Friday. The binder check will be the final grade for the second trimester. The test will become the first grade of the third trimester. Next week, we will begin our discussion of classification.

With only one trimester left in the school year, I want to encourage students to continue working hard! Turn in your assignments on time, and be prepared for class every day! This trimester, we will focus on five of the six kingdoms of living things (archaebacteria, eubacteria, protists, fungi, and animals). We learned about the the remaining kingdom (plants) earlier this year.

2/22

This week, we reinforced our ideas about natural selection by doing a "peppered moth simulation." We reviewed the experiment that was done in Manchester, England with the pale and dark peppered moths. Before the 1850's, the pale variety of moths were more common because they blended in with the lichen-covered trees. As the industrial revolution began in the 1850's, the trees became covered in smoke and soot, and gradually, the dark variety of moth became more common. In our lab, we used two different colored backgrounds to represent the non-polluted (pale) and the polluted (dark) tree trunks. Small circles were cut out to represent pale and dark moths. Students became predators (birds), and had to use tweezers pick up as many "moths" off of each background as they could in 20 seconds. While some students struggled as predators (I know it was difficult!), others excelled! Great job to everyone for putting in a good effort!

Next week we will wrap up our evolution chapter. We will discuss other evidence for evolution (the fossil record, comparative structures, vestigial structures, and plate tectonics). We will also do a lab that will test the students' ability to determine the relative age of fossils. We will have our chapter test on Friday!

2/15

This week, students were introduced to the concepts of adaptations, evolution, and natural selection. We discussed the voyage of Charles Darwin and the important discoveries that he made on the Galapagos Islands. We spent two days in class doing a "Designer Animal Activity." In this activity, students were given four environments to choose from, and they were required to design an animal with unique adaptations to survive and thrive in their chosen environment. Students had to consider what their animal would eat, how it would defend itself, maintain body temperature, care for its young, find shelter, etc. After designing everything, students had to choose a card that determined how their environment had changed (volcano eruptions, global warming, meteorites, shift in planetary rotation, etc), and then decide whether their animal still had the right adaptations to survive. Overall, students came up with some VERY interesting animals! Unfortunately, many of our "designer animals" were not adapted to survive the harsh environmenal changes. On Friday we looked at several examples of natural selection "in action." Some of these examples included the lizards from New Mexico, Hawiian crickets, insectiside-resistant insects, antibiotic-resistant bacteria, and the peppered moths from England. Next week we will do a lab to simulate the "peppered moth" example of natural selection.

2/8

This week, we watched the remaining portion of the genetic engineering video, and we had some very good discussions about the ethical situations that were presented. The two major questions that we debated were, "is it unfair to use animals to beneift mankind?" and "would it be ethical to use cloning to save endangered animals or bring back extinct ones if we could?" We had a lot of different student viewpoints and some great opinons! We spent the remainder of our short week reviewing for our DNA quest by playing the "overhead letter game." We took our quest on Friday and will be focusing on the basic principles of evolution next week. Students can look forward to "designing" their own animal next week.

1/31

This week, we discovered how the DNA code works. We discussed how 3 DNA bases code for an amino acid and that a group of amino acids make up proteins (the chemical messengers that tell the cell what to do). We even had the chance to "view" DNA when we did our DNA isolation lab on Tuesday. Remember that you can take this lab home and try to extract DNA from other sources! We began our discussion of genetic engineering on Wednesday and started watching a video on this topic on Thursday. We will continue disscussing the "advances in genetics" next week and will take a 50 point "quest" over our DNA notes on Friday.

A big CONGRATULATIONS goes out to the 7th grade PC students who ALL received first place standings at the Science Fair on January 26th. Pictures are going to be posted soon!