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.