Scribe Post for January 27th, 2011

Date- January 27th, 2011




Announcements- Tommorrow, Friday, January 28th, 2011, we have a bio day that is located in the auditorium. Go straight to the auditorium during period 8.




In Class- We did a lab in class on natuaral selection. It can be found on pages 17-19 in your green unit packet. The procedure for this lab went as follows:

• You would spread a piece of fabric out on the table.
• Grab 10 different colors of paper, and hole punch each color 10 times and put them on the cloth, so you have a total of 100.
• 2 members of the group would act as "predators," which means that they would pick 40 pieces of paper each, but turning away after each pick and picking the 1st color that they saw with no hesitation.
• Collect the 20 remaining pieces on the cloth and record the number of each color remaining on the data table on page 18.
• Add 4 chips of the same color for every chip that remains from the original population, now the total should be 100 again.
• Repeat the picking procedure for the second and third generations and record your data in the same place.

Purpose- The most important thing when doing these labs is to understand why they are being done. The purpose of this lab is to learn how natural selection works. And to also reinforce your concept of to how natural selection works with a demonstration.

NATURAL SELECTION: The process by which organisms with variations most suited to their local environment survive and leave more offspring. It occurs in any situation when more individuals are born than can survive, there is heritable variation, and variable fitness among individuals.

(Those terms and definitions can be forund in your textbook, Ch. 16, section 3.)

NEXT SCRIBER: Sammie

Scribepost 1/27/11

Date...1.27.11



Announcments...nothing interesting that anybody needs to know about.




Homework...read 16.2 and 16.3 and take notes on 16.3, also finish the lab about bird beaks we started in class and do the graph




In class...we began the lab on page 4 of the unipacket. the lab was about the evolution of bird's beaks for whatever food source they have. We were split into our new lab groups and we began the experiments with the 4 different types of "beaks," forceps, a large spoon, a staple remover, and pliers were supposed to represent beaks. In the lab there were 5 different experiments, one where we had to remove styrofoam peices from a tub, one were we had to pick out single grains of rice from a log, one were we had to remove staples from a paper rabbit, one were we had to pick rubberband out of a box with a lot of shredded paper init, and one were we had to not only pick up sunflower seeds but also crack them with our "beak."


The next scriber will be...Jake J

Scribepost Jan. 25 2011

Announcements: All homework assignments and unit calendars will be posted on moodle.

Homework:  Read chapter 16.2 (no notes required) and chapter 16.3 notes.  Both will be checked in on thursday.

What we did in class:  Today in class we took notes from Mr. Paek's lecture about Darwin vs. Lamark. Also we got the unit packet for the new unit(Evolution 101) which took up most of class.  Then we ended class with watching more of the Charles Darwin movie for the last 10 minutes of class.  

Lamark:  Had three main theories on evolution.

1. The Desire to Change-  animals and organisms change in structure because of a desire to improve.  An example is that a giraffe's neck got longer because they stretched to get leave at the top of branches.
2. Use and Disuse-  use it or lose it.  If decided not to use then something would be lost over time.  Mr. Paek described this by saying if he didn't like his thumb and decide to wrap it up and not use it for the rest of his life, it would lose muscle.  Now becoming factor of his offspring.
3. Acquired characteristics were inherited-  Any changes in the adult were passed on to the offspring.  Example is the stretched giraffe necks were now inherited by the young.

While talking discussing this Mr. Paek said based on Lamark's theories, if he wanted his son to be really strong he could start working out really often so he becomes really strong.  Then have a child that way his son has a better chance of being strong.  Then he thought of this video and showed it to us.  

http://www.youtube.com/watch?v=T-CMrswt_1A

Darwin:  Came up with five theories of evolution of his own too.

1. Overproduction of Offspring-  Organisms tend to produce more offspring then needed to replace numbers.
2. Struggle for Existence-  Competition for resources and predation are always present. The example used in class was that Mr. Paek would tell us only 1 person would get an A second semester and the rest would get either a C or F.  So, then we would all be more competitive to get that one spot for the A.
3. Variations in Populations exist-  Differences in structure exist at birth not acquired.  These variations are inherited from the parents.
4. Fitness-  Organism must have a physical trait or behavior so they can survive and reproduce. 
5. Common Descent-  Some species share a common ancestor.

Natural Selection:  The organism that are best suited for the present environment conditions will survive to produce therefore passing on their characteristics to their offspring. (Survival of the fittest)

• Conditions that help-  Mutations are a source of variation in genes. Also, gene flow when genes are moving between populations.
• Adaptations-  Traits that survive from one generation to the next.

That was it for today, the next scriber will be Donnie.