1. Changing Allelic Frequencies
Microevolution
Changing Allelic Frequencies

2. Adaptation is a beneficial gene that will help an organism to survive and reproduce.
NOTE-
1. Evolution only works on phenotype not genotype.
2. Evolution works on populations not individuals.
Microevolution-how allelic frequencies in a population change.
Macroevolution-how accumulations of changes, results in new species or speciation.
This saddle-back tortoise has an adaptation of an elevated shell to reach food others can not.

3. Adaptation is a beneficial gene that will help an organism to survive and reproduce. They come from mutations.
NOTE-
1. Evolution only works on phenotype not genotype.
2. Evolution works on populations not individuals.
Microevolution-how allelic frequencies in a population change.
Macroevolution-how accumulations of changes, results in new species or speciation.
This saddle-back tortoise has an adaptation of an elevated shell to reach food others can not.

4. Species-a group of interbreeding organisms that produce viable and fertile offspring in nature.
Gene pool-sum total of all the genes in a given species.
Allelic frequency- is the percent occurance for a given allele.
How does variation in a population arise?
1. Mutations and new genes provide the raw material for evolution.
2. Meiosis and sexual reproduction will produce new recombinants of phenotypes which natural selection operates.

5. Species-a group of interbreed-ing organisms that produce viable and fertile offspring in nature.
Gene pool-sum total of all the genes in a given species.
Allelic frequency- is the percent occurance for a given allele.
How does variation in a population arise?
1. Mutations and new genes provide the raw material for evolution.
2. Meiosis and sexual reproduction will produce new recombinants of phenotypes which natural selection operates.

6. This wisteria on the right has a mutation which causes white flowers instead of purple

7. Mutations and new genes
*MOST mutations are deleterious and recessive.
Gene level
1. point mutations
2. frame shift mutation
Chromosomal level
3. chromosomal rearrangement
a. inversion b. deletion
c. duplicaton d. translocation
4. gene replication and modification.
EVOLUTION EDITS AND DOES NOT START FROM SCRATCH.

8. Mutations and new genes
*MOST mutations are deleterious and recessive.
Gene level
1. point mutations
2. frame shift mutation
Chromosomal level
3. chromosomal rearrangement
a. inversion b. deletion
c. duplicaton d. translocation
4. gene replication and modification
EVOLUTION EDITS AND DOES NOT START FROM SCRATCH

9. Some mutation do not change the functioning of the protein
Some mutation do not change the functioning of the protein. Therefore an accumulation of mutations can be used as an evolutionary clock. On the average cytochrome C mutates every 17 million years. Between mammals and reptiles there are 15 different amino acids or mutations. That means that mammals and reptiles diverged 265 million years ago. that means that there was one mutation every 17 million years on the average.

10. Some mutation do not change the functioning of the protein
Some mutation do not change the functioning of the protein. Therefore an accumulation of mutations can be used an evolutionary clock. On the average cytochrome C mutates every 17 million years. Between mammals and reptiles there are 15 different amino acids or mutations. That means that mammals and reptiles diverged 265 million years ago. that means that there was one mutation every 17 million years on the average.

12. Myoglobin is a protein that binds with oxygen in the muscles
Myoglobin is a protein that binds with oxygen in the muscles. This gene has been through duplication and modified many times. It has given rise to the hemoglobin gene

13. Myoglobin is a protein that binds with oxygen in the muscles
Myoglobin is a protein that binds with oxygen in the muscles. This gene has been duplication and modified many times. It has given rise to the hemoglobin gene

14. If the following conditions are met then allelic frequency remain the same and NO EVOLUTION occurs.
Hardy-Weinberg Equillibrium
*1. Population must be large enough that chance is not a factor.
*2. Population must be isolated (no immigration or emigration) to prevent gene flow.
3. No mutations or mutational equillibrium
4. Complete random mating with respect to time and space
5. Every offspring has an equal chance of survival without reguard to phenotypes.

15. If the following conditions are met then allelic frequency remain the same and NO EVOLUTION occurs.
Hardy-Weinberg Equillibrium
*1. Population must be large enough that chance is not a factor.
*2. Population must be isolated (no immigration or emigration) to prevent gene flow.
3. No mutations or mutational equillibrium
4. Complete random mating with respect to time and space
5. Every offspring has an equal chance of survival without reguard to phenotypes.

16. 1. Condition #1 can be met. It is important to have large populations in order so that the loss of genes will not be a factor. Small population can experience genetic drift.
Also if a small population moves to another area, chances are the gene pool will be different from the original gene pool. This is called the founder effect.
2. Condition #2 can be met if the population is isolated. If individuals come and go into a population, the allelic frequencies change and evolution occurs.

17. 1. Condition #1 can be met. It is important to have large populations in order so that the loss of genes will not be a factor. Small population can experience genetic drift.
Also if a small population moves to another area, chances the gene pool will be different from the original gene pool. This is called the founder effect.
2. Condition #2 can be met if the population is isolated. If individuals come and go into a population, the allelic frequencies change and evolution occurs.

18. 3. Condition #3 can NEVER be met because one can never stop mutations
3. Condition #3 can NEVER be met because one can never stop mutations. Mutational equillibrium can never be met.
4. Condition #4 can NEVER be met. Mating is never random.
A piece of pollen from an apple tree in Ohio is more like to pollinate a tree in Ohio than one in Washington state.
5. Condition #5 can never be met. There will always be variation. Some variation will help organisms to breed and survive.

19. 3. Condition #3 can NEVER be met because one can never stop mutations
3. Condition #3 can NEVER be met because one can never stop mutations. Mutational equillibrium can never be met.
4. Condition #4 can NEVER be met. Mating is never random.
A piece of pollen from an apple tree in Ohio is more like to pollinate a tree in Ohio than one in Washington state.
5. Condition #5 can never be met. There will always be variation. Some variation will help organisms to breed and survive.

20. Unstable variation-means that one trait is more beneficial in a given environment than another and there is a selection pressure operating on it.

21. Unstable variation-means that one trait is more beneficial in a given environment than another and there is a selection pressure operating on it.

22. Types of selection
1. Directional selection-in a given population there is variation, one extreme is now favored over the other phenotypes. This gives rise to an increase in the favored gene. The allelic frequency changes and moves to the more favored trait. Note-many traits are are controlled by many genes (multifactorial inheritance). It is the combination of the gene that allows for many phenotypes. Ex- Height is multifactorial inherited.

23. i. e. The okapi and giraffe are thought to have a common ancestor
i.e. The okapi and giraffe are thought to have a common ancestor. There was a selection pressure for the giraffe to have a longer neck to obtain food that other animals can not reach. Over time, that trait was selected for.

24. Ex- This graph shows how researchers at U
Ex- This graph shows how researchers at U. Illinois selected for an increase in the oil content of corn through 50 generations (directional selection). It is thought that this is a polygentic trait (multifactorial) and that the increase in oil resulted from new recombinations of genes (more genes for oil were "turned on" than new mutations

25. Types of selection
1. Directional selection-one extreme is favored over the other phenotypes. This gives rise to an increase in the favored gene. The allelic frequency changes and moves to the more favored trait. Note-many traits are are controlled by many genes (multifactorial inheritance). It is the combination of the gene that allows for many phenotypes. Ex- Height is multi-factorial inherited.

26. 2. Disruptive selection (diversifying selection)-There is a selection pressure for the two extremes, this causes an increase for the traits at the extreme.
Ex- Suppose that gametes (sperm and eggs) were the same size (isogamy). It is thought that there were two selection pressures operating on the two types of gametes.
1. Selection pressure of storing food for future embryo would work on eggs.
2. Selection pressure for greatest number of gametes that could swim the fastest would work on sperm.
The end result are two very different gametes (heterogamy).

27. 2. Disruptive selection (diversifying selection)-There is a selection pressure for the two extremes, this causes an increase for the traits at the extreme.
Ex- Suppose that gametes were the same size (isogamy). Two selection pressures operating on the two types of gametes.
1. Selection pressure of storing food for future embryo would work on eggs.
2. Selection pressure for greatest number of gametes that could swim the fastest would work on sperm.
The end result are two very different gametes (heterogamy).

28. 3. Stabilizing selection- In this case, the intermediate phenotype is selected for and the extremes are selected against. This reduces variation in the population.

29. 3. Stabilizing selection- In this case, the intermediate phenotype is selected for and the extremes are selected against. This reduces variation in the population.

30. i. e. Human birth weight is on the average 3-4 kg
i.e. Human birth weight is on the average 3-4 kg. It is well known that the smaller the baby (>3-4 kg), the less likely it will survive but it is also detremental to have large babies and the survival rate decreases (<3-4 kg)

31. i. e. Human birth weight is on the average 3-4 kg
i.e. Human birth weight is on the average 3-4 kg. It is well known that the smaller the baby (>3-4 kg), the less likely it will survive but it is also detrimental to have large babies and the survival rate decreases (<3-4 kg).

32. It is possible to have variation in population that is stable and one phenotype is not favored over another therefore the allelic frequencies do not change. This may be due to-
a. the environment may be variable and one morph may do better in one environment than the other
b. one morph may be better adapted to one time of the year more than the other. The lady bird beetle has 2 morphs. The red is much better as survival in the spring and winter. The black morph is much better with survival in the summer and fall.

33. It is possible to have variation in population that is stable and one phenotype is not favored over another therefore the allelic frequencies do not change. This may be due to-
a. the environment may be variable and one morph may do better in one environment than the other
b. one morph may be better adapted to one time of the year more than the other. The lady bird beetle has 2 morphs. The red is much better as survival in the spring and winter. The black morph is much better with survival in the summer and fall.