Test Today & Tomorrow

Today and tomorrow students will have a test on evolution (chapters 13-15). It's hard to believe, but this is the last grade students will have for the winter term!

Extinction!

Today (and on Saturday) students watched another part of the PBS Evolution Series, Extinction!

"Five mass extinctions have occurred since life began on Earth. Are humans causing the next mass extinction? And what does evolutionary theory predict for the world we will leave to our descendants?" To learn more, click here.

Phylogeny & Classification

Today we wrapped up chapter 15 by reviewing cladograms and practicing how to interpret and identify clades. Click on the picture below to see a larger version of this wonderful tree of life.

Lab 11: Protein Electrophoresis Analysis

On Saturday we did a variation of Wednesday's lab, which has terrible results. The variation is was as follows:

1. Get into four groups

2. Each group will do a different sample.

2a. Bean

2b. Quinoa

2c. Liver

2d. Fish

3. Using the above sample given, follow the grid below

Label 6 micro tubes as follows

Well 1. (5% vinegar): add 20ul of Sample, add 15 ul of 5% vinegar, add 12 ul of loading dye, incubate at room temp for 5 min, add 20ul to gel

Well 2 (5% NaCl): add 20ul of Sample, add 15ul of 5% NaCl, add 12 ul of loading dye, incubate at room temp for 5 min, add 20ul to gel

Well 3 (35% NaCl): add 20ul of Sample, add 15ul of 35% NaCl, add 12 ul of loading dye, incubate at room temp for 5 min, add 20ul to gel

Well 4 (95 C): add 20ul of Sample, add 15ul of water, add 12 ul of loading dye, incubate at 95 C for 5 min, add 20ul to gel

Well 5 (37 C): add 20ul of Sample, add 15ul of water, add 12 ul of loading dye, incubate at 37 C for 5 min, add 20ul to gel

Well 6 (Normal): add 20ul of Sample, add 15ul of water, add 12 ul of loading dye, incubate at room temp for 5 min, add 20ul to gel,

Well 7 (Negative control) Loading Dye , add 20ul to gel

4. Once gels are loaded, run at 130 V for 1 hour.

5. Upon completion of gels, stain for 1 hour

6. Remove stain and allow to sit over night in distilled water

This protocol actually yielded results and so today all classes will be analyzing the results. Since A and D blocks actually did this lab, they will provide feedback on how to improve the lab for next year's students.

Evolution PowerPoints on BlackBoard

In the "course documents" section of BlackBoard there is a folder titled "Evolution PowerPoints." There are four PowerPoints in there with information on speciation, classification, macroevolution and the mechanism of microevolution. Open the folder and you will be able to see a short description of the information in the PowerPoint.

This information is to help you review it is not "new information" (although if you look at classification today -- Monday -- it will seem new because we are learning that on Tuesday).

Questions on Evolution??

Post them here!

If there is something you have a question about for things in chapters 13-15, post them here. I will either answer the questions or direct you to where you can find the answer in your book or online.

Why set this up? So your peers can learn from the questions you ask.

Questions will be answered on this post through Wednesday 2.25.09 at 9pm.

Evolution Unit Test

Here is what you should study for the test on chapters 13-15.

* 13 packet, parts one and two

* Online evolution quiz

* Movie notes sheets Why Sex? and Great Transformations

* Chapter 14 Summary and Review Questions

* Constructing an amaylase evolutionary tree lab (can you interpret a cladogram?) If you are confused about this section you can go back and review this post.

YOU WILL HAVE A FEW MORE NOTES ON CHAPTER 15 IN CLASS ON TUESDAY as well as the opportunity to get your questions answered.

Great Transformations

To help supplement the book, we are continuing with watching the PBS evolution series. Today we watched Great Transformations. Click the picture below to get to activities that were mentioned in the video.

Why Sex?

In evolutionary terms, sex is more important than life itself. Sex fuels evolutionary change by adding variation to the gene pool. The powerful urge to pass our genes on to the next generation has likely changed the face of human culture in ways we're only beginning to understand.

After some careful thought, the activity we were going to do today was more hands-on than minds-on, so... Instead we watched "Why Sex" from the PBS Evolution Series.

Students were asked to answer the following questions:

1. What makes the lizards unique?

2. They do so well, as all female species, why is there sex? Are males really necessary?

3. What is the biological reason for sexual reproduction?

4. Sonora, Mexico – What is the scientists studying?

5. What is the Red Queen Theory? Why is it called that?

6. Sex generates variability in a population.

7. Origins of Sex: How did it all begin?

8. “The sight of a Peacock makes me sick” —Darwin. Why did he say this?

9. What is sexual dimorphism?

10. What did the peacock experiments provide support for?

11. Explain behavioral traits v. physical traits

12. Song Birds – parenting, social monogamy & role reversal.

13. What are the two chimp populations that are studied?

14. What is one explanation given for why different behaviors have emerged in each population?

15. How is infanticide interrupted?

Saturday Lab & Speciation Next Week

For what A & D block did in lab today click here.

On Tuesday we will be doing a short, hands-on activity on speciation. Before coming to class, please read sections 14.1-14.3. It's only four pages and knowing this information will help you understanding what's going on.

Hardy-Weinberg & Microevolution

Microevolution happens on a small scale (within a single population), while macroevolution (which we will be talking about in Chapter 15) happens on a scale that transcends the boundaries of a single species. Despite their differences, evolution at both of these levels relies on the same, established mechanisms of evolutionary change.

Today (and tomorrow for C & D blocks) we are wrapping up chapter 13, which includes microevolution. The key things that we are focusing on today are:

* Microevolution is a change in a population's gene pool over time.
* What the Hardy-Weinberg Equation is and how it is used in public health
* Causes of microevolution
* Real examples for the bottleneck & founder effects.
* Polymorphism in populations
* Geographic variation (clines)

You will need to finish the last five pages of chapter 13 for homework. The last page in your packet lists the key concepts and terms for those five pages, there is space provided for you to take notes.

Once you are finished taking notes, take the self quiz located in the “Evolution” sidebar, click on Self Quiz on Evolution. Just guess for question numbers 3, 11, 20 and 22-25 (you are not responsible for this information). You need to answer all the questions if you want to see what the correct answers are.

This is a great way for you to see if you actually understand the material. Try to answer the questions without looking at your notes.

Lab 10: Constructing an Amylase Evolutionary Tree

Amylase is an enzyme in human saliva that breaks down starch. If you chew a piece of plain white bread, eventually, it will start to taste sweet. What's going on here? Well, amylase is breaking down the starches (a storage polysaccharide) and releasing the sugars. What does this have to do with evolution?

Scientists can look at evolutionary relationships based not only on homologies but also by using protein sequences; after all amino acids are the genotypes which make proteins which display phenotypes. In this lab you will be constructing an evolutionary tree by comparing amino acid sequences in amylase. The biggest thing to remember in this lab is:

GO SLOW TO GO FAST

What does that mean? It means take your time, because one little careless mistake will throw off the rest of your data.

Does what you are learning in the lab have any real-world connections? YES! For homework:

Part One: Read Understanding Phylogenies, make sure you click "next" at the bottom of the page, so you get to "Understanding Phylogenies (2 of 2)."

Part Two: Read Evolutionary Evidence Takes The Stand and write a 3-2-1 using COMPLETE SENTENCES. 3 Things you learned, 2 things you have questions about and 1 thing you would like to learn more about.

This is due the next time class meets.

Titanoboa - Titanic Boa Fossil From Colombia Is World's Largest Snake

This is the headline from February 4th, 2009 Scientific Blogging. "Estimated Titanoboa size: 42 feet (13 meters); 1140 kilograms. According to the Guinness Book of World Records, the longest snake ever measured was 10 meters (33 feet) in length. The heaviest snake, a python, weighed 183 kilograms (403 pounds)."

To read more on this story, see pictures and even a video clip, click here.

Evidence of Evolution, Darwin's Theory & The Modern Synthesis

Tomorrow in class we will be working on 13.2 through 13.6. Key topics include:
*the fossil record
*biogeography
*comparative anatomy
*comparative embryology
*molecular biology
*natural selection as a component of evolution
*the case study of the quiet crickets
*populations & introducing population genetics

To sum up natural selection and the forces involved in that process we will watch this video clip:

and answer these questions (which are adapted from the PBS teacher's website)
1. Below are four components of natural selection. Describe each of these components.

Genetic variation:

Overproduction of offspring:

Struggle for existence:

Differential survival and reproduction:

2. What kinds of limited resources can create a struggle between individuals in a population?

3. What kinds of variable traits within a population might natural selection act upon?

4. How does natural selection affect the genetic variation within the next generation of the same population?

Lab Homework: Print and read the lab handout. C block, you must do this for Wednesday, D & A blocks you need to complete this by Saturday. Read carefully, as there is a good chance you will have a pre-lab quiz. You do not need to paste this into your lab notebooks.

Evolution is.. Evolution is not..

It is a lot more fun to actually use biotechnology than it is to talk about it, so rather than complete chapter 12 as a separate topic, it will be incorporated into lab time. As a result it is time to start chapter 13!

Class started today with a brainstorming session answering the prompts "Evolution is..." and "Evolution is not..." There were some great talking points and questions raised during this time. After brainstorming, students took a pre-assessment survey at the end of the unit students will take this survey again. One statement in the survey (number 15) is: "Evolution is only a theory." To directly address this statement, we watched an excerpt from the PBS series Evolution.


The next clip we watched addresses section 13.1: A sea voyage helped Darwin frame his theory of evolution.



In this clip Darwin talks about a "tree of life," today scientists can you cladograms (like the ones below) to show evolutionary relationships. Cladograms can be simple representations like this one....Or they can be the result of complex research involving only genus and specie, like this one for dinosaurs. Click the picture to make it larger.

In lab this week you will be making cladograms using genetic sequences.

Update for the Remainder of the Week

I will be in Boston on Friday and Saturday, but you still have class. Below is the schedule for who is covering your class as well as what you will be doing.

Friday:

D Block: Mrs. Llewelyn
Bring your books and complete the packet for sections 11.15-11.19. You can also work on your abstract.

C Block: Mr. Wardrop
Bring your books and complete the packet for sections 11.15-11.19. You can also work on your abstract.

Saturday:

D Block: Ms. Ryder
Bring to class a hard copy of the Stem Cells, Cloning and Regeneration Handout. You will be watching video and lecture clips from the HHMI series.

A Block: Mrs. Bryan
Bring your books and complete the packet for sections 11.15-11.19. You can also work on your abstract.

Stem Cells, Regeneration & Cloning

Today, tomorrow and Friday (depending on when your class meets) we will be expanding on the minuscule amount of information in your text on stem cells, regeneration and cloning. Using video clips and animations from HHMI's 2006 Holiday Lecture Series, we will learn, among other things, where embryonic stem cell come from, prior theories on human development and about somatic cell nuclear transfer.

Click here for video clips

Click here for animation

Welcome Back with Gene Regulation

Today we slowly got back into the swing of things by learning about gene regulation in prokaryotes. In the next class period we will delve into cell differentiation and stem cell research using video clips from the HHMI lectures.