Evolution and Natural Selection

This week we started in to our LAST chapter :) :) :) on Evolution and Natural Selection.  The daily questions we received Tuesday, Wednesday and Today are below.  I know that you covered basics of evolution and natural selection last year but this year we will be applying our understanding of Genetics and gene expression to get a better understanding of how exactly allele frequencies change over time.
Tuesday:
1.  Which population of organisms would be in greatest danger of becoming extinct?
***A population of organisms having few variations living in an unstable environment.
*Having little variation is not a good thing when a major environmental change occurs.


2.  In order for a new species to develop, there must be a change in the
**Genetic makeup of a population.  (This can be DUE to a change in the temperature or migration patterns, but ultimately it comes down to a change in the allele frequencies of a population)


3.  Which statement is NOT part of the concept of natural selection?
A.  Individuals that possess the most favorable variations will have the best chance of reproducing.
B.  Variation occurs among individuals in a population
C. More individuals are produced than will survive
D.  Genes of an individual adapt to a changing environment***GENES do not adapt - individuals adapt and populations adapt - but genes do not.  They may "change" due to random mutations though.

** 2  - a decrease in the advantage of having white fur.  Since over a 10 year period the presence of ANY white rabbits was eliminated, that most likely means that having white fur was no longer a good thing.
Which statement best describes a current understanding of natural selection?
A.  Natural Selection influences the frequency of an adaptation in a population.

We then started into the notes on Evolution and natural selection.  Please check edline for these

Wednesday May 2^nd

The scientist who traveled to the Galapagos island’s was……… Charles Darwin

He specifically looked at what type of organisms? Finches (along with many other interesting creatures!!)

True or False:  All Mutations are Bad FALSE!!!  Mutations simply mean a change in DNA  This can sometimes have an advantage, sometimes be bad, or other times have no affect on the phenotype.  For instance, i showed you the clip about a child that was born with 6 fully functional fingers and toes (see Below)

True or False:  Not all mutations are passed on to our offspring. TRUE - Only mutations that occur in germ line cells (those that will go through meiosis to become our gametes) will be passed on to our offpsring.

Thursday May 3^rd

*What did Darwin notice about the finches and what did that lead him to believe about the “evolution” of them? He noticed that their beak shapes directly corresponded to the type of food they ate.  What he theorized was that the finches has migrated from the main land of South America and overtime adapted to different food sources.  He called this "Descent with modification"

*With our understanding of genetics, these different “variations” are known as what? Alleles

*What do you think caused these different variations? Mutations

*What two types of variations do you believe would provide an “advantage” to a species?  Any allele that would allow them to survive (eat and not be eaten) and reproduce.

Today we continued with the notes and will next move into some chapters from the book Survival of the Sickest.