Unit 10 Population Genetics/Evolution Name:______
Chapter 11 in text book
Population Genetics is the study of______
What defines a Population?
A group of the ______
No two individuals are identical, there are some variations. (like within the human population)
The more ______individuals survive to ______
What is Speciation?
This is the ______
One Species may ______
A species may ______
This requires very Long periods of time!!!
Today’s Modern Theory of Evolution
1. ______are responsible for the inheritance of characteristics.
2. ______, NOT ______evolve due to ______&______
3. ______is usually due to the ______.
What causes populations of organisms to EVOLVE??? (5 factors)
1. Genetic drift:______.
2 factors that can cause genetic drift:
Bottleneck Effect:Founders Effect
**A drastic reduction in population**When a small number of individuals
**Reduced ______colonize a new area.
**Smaller ______
2. Natural Selection: ______
______
Causes ADAPTATION !!!
3. Gene Flow: ______
Ex: Southeast Asia gene pool was changed when ______
4. Mutation:______
5. Non-Random Mating: ______
Nice
Feathers!
Having a lot of ______is GOOD!!!!
The Gene Pool!!!
**Members of a population (species) can______
**Species have a ______
**Gene Pool______
Allele Frequencies
Different andchanging combinations of alleles in a gene pool can be formed when ______
______.
The Allele Frequency is the ______.
Example: Is the frequency of the brown eye allele more common that the blue eye allele in this classroom?
Allele Frequency= The number of times an allele occurs
The total number of all alleles for that gene
Let’s practice: do the mice population Q here:
Scientists can track the frequency of an allele over time to see the changes in populations!!
If a certain trait’s allele frequency is 100, what kind of genetic variation of that allele is in the population?
There are 2 MAIN Sources for Variation in Allele Frequencies
1. Mutation
2. Recombination of alleles through the process of ______
????why aren’t mutations in somatic cells sources of genetic variation?
As Natural Selection Progresses over time…..Evolution Happens!
We usually see evolution due to natural selection organized into 3 types situations: Modes
1. Directional Selection:
**Favors individuals at ______
**Most common during times of ______or when
moving to new habitats.
**Ex:: ______
2. Disruptive Selection
**Favors both extremes ______
**Occurs when environmental change______
**Can be a pathway for species formation WITHOUT ______
** Ex:______
3. Stabalizing Selection
**Favors the intermediate phenotype over the ______
**Reduces ______and maintains______
**Ex: ______
How Does Natural Selection Affect Allele Frequency??
1. Mutations provide the raw material ______
2. ______because it is the only way that differences among organisms are created.
3. Natural Selection acts on ______by changing the % of alleles in the population.
How do The New Species Occur??? Must besomehow ______
3 basic barriers that lead to isolation:
1. Behavioral Barriers:______
______
2. Geographic Barriers:______
______
3. Temporal Barriers: ______
______
THIS ALL CONTRIBUTES TO ______
New Species Evolve in a few types of Patterns(review)
1. Convergent Evolution: When different species adapt to similar environments
______characteristics in ______
Ex: Dophin/______
2. Divergent Evolution: Closely related species evolve in different directions.
Evolution towards ______characteristics in ______
EX: ______
3. Co-Evolution: When ______
______.
Ex: Acacia plant/______
These new species that are created through natural selection have done so in repeating patterns throughout the history of the Earth! There are 2 types of repeating patterns of speciation over time that scientists have seen. They are:
Punctuated EquilibriumAdaptive Radiation
A BURST of evolutionary ______Diversification (variation of traits) of ______
Followed by long periods of______ancestral species into ______
______descendent species.
EX: ______EX: ______
Genetic Variations(______)
within______.