1. Evolution… It’s a gene thing
Mutations
Gene Flow
Genetic Drift
Natural Selection
Study quiz

2. How are populations, genes and evolution related?
Click here to return to the table of contents

3. Genes and the environment interact to determine traits.
The gene pool is the sum of the genes in a population.
Evolution is the change over time of allele frequencies within a population.
Click here to return to the table of contents

4. Mutations Spontaneous Induced
Mutation is a permanent change in a cell’s DNA. Mutations create variation in the gene pool. The less favorable mutations tend to be removed by natural selection and the more favorable usually continue and result in an evolutionary change. Mutations are very rare and have a possibility of having a harmful effect. A mutation may lead to the death of an organism before it can reproduce keeping the genetic change from being passed along.
Induced
Click here to return to the table of contents

5. Point Mutations Alteration of just one base pair of a gene.
Most common type of mutation.
Point mutations: a nucleotide sequence error resulting from incorrect insertion of base sequences in DNA.
Click here to return to the table of contents

6. Chromosomal Deletion
Chromosomal Deletion: part of the chromosome is omitted in cell division. Several birth defects are related to chromosomal deletion such as cleft palate.
Click here to return to the table of contents

7. Gene Flow
Gene Flow: movement of alleles between populations. Occurs when individuals from one population migrate into the territory of a new population with a different gene pool.
Click here to return to the table of contents

8. Here you can see how these plants from California adapted to create a new species which grows in Hawaii. Their populations are split by several hundred miles of ocean.
Click here to return to the table of contents

9. Genetic Drift A game of chance
Genetic drift is a change in allele frequencies that can occur by chance in populations. Smaller populations are more susceptible to more dramatic change over a fewer generations as opposite of larger generations. Bottle neck effect and founders effect.
Click here to return to the table of contents

10. Genetic Drift: The Bottleneck Effect
Population bottlenecks occur when a populations size is reduced for at lease one generation. Because genetic drift occurs more quickly to reduce genetic variation in small populations, undergoing a bottleneck can reduce a populations variation by a lot even if it does not last for very many generations.
Reduced variation means that the population may not be able to adapt to new pressures such as climate change or a change in available resources.
Click here to return to the table of contents

11. Genetic Drift: Founder Effect
Founder effect is when a subpopulation migrates to a new area, it may take with it only a part of the gene pool of the original population.
Click here to return to the table of contents

12. Individuals in some species choose their mates based on appearance or behavior. This behavior tends to bring similar alleles together but does not modify their frequencies.
Click here to return to the table of contents

13. Allele frequency can be affected if some population members mate more than others. This is called sexual selection.
Click here to return to the table of contents

14. “The most powerful force in evolution.” “Fit” for the environment
Natural Selection
“The most powerful force in evolution.”
“Fit” for the environment
Some individuals have traits that make them a better “fit” for their environment thus leading to more success in that environment. The individuals more likely to survive will be more likely to reproduce and pass on their traits.
Click here to return to the table of contents

15. It’s a gene thing quiz
After reading the question click on the answer button to reveal the correct answer and explanation.
Click here to return to the table of contents

16. 1.) This permanent change in DNA alters the product of a gene.
Click here to return to the table of contents

17. Mutations are the permanent change in genes which cause variation in the gene pool. These can be both beneficial or detrimental.
Click here to return to the table of contents

18. 2.) All of these pictures can lead to what type of mutation?
Click here to return to the table of contents

19. Induced mutations can be cause by chemicals, radiation and viral infections.
Click here to return to the table of contents

20. 3.) Gene _______ is the movement of alleles from one population to another.
Click here to return to the table of contents

21. Gene flow is the movement of alleles from one population to another
Gene flow is the movement of alleles from one population to another. Gene flow is more difficult when there are large barriers separating environments.
Click here to return to the table of contents

22. 4.) Cleft palate is a birth defect which is caused by which type of mutation?
Click here to return to the table of contents

23. Chromosomal deletion is the cause of cleft palate
Chromosomal deletion is the cause of cleft palate. It happens when a portion of the chromosome is deleted when the cells divide.
Click here to return to the table of contents

24. 4.) This common type of mutation occurs when only one base pair is altered.
Click here to return to the table of contents

25. Point mutations occur when only one base pair is altered (substituted or removed) from the gene frequency. These are the most common types of mutations.
Click here to return to the table of contents

26. 5.) Genetic drift can happen by two different means, the Founder effect and the __________.
Click here to return to the table of contents

27. The bottleneck effect occurs when a population size decreases for at least one generation causing a reduction in population variation.
Click here to return to the table of contents

28. 6.) __________ _____________ is a phenomenon in which the most species who can adapt to their environment will survive while others may not.
Click here to return to the table of contents

29. Natural Selection is quite possibly “the most powerful force in evolution.” For anything to live in this environment it would take many generations of adaptation. Polar bears have the necessary traits to survive in the harsh arctic.
Click here to return to the table of contents

30. You’re finished with the quiz!
Click on these pictures to Check out great sites for more information on the genetics of evolution.
Click here to return to the table of contents