1. Directional Selection
Alanna, Hailey, Sam

2. Table of Contents What is Directional Selection? Examples The Results
What is Artificial Breeding?
Pros & Cons
Conclusion

3. What is it? A form of Natural Selection
A phenotype of a species that is favored over the others
Through natural selection the species’ generation will inherit this enhanced trait
Eventually this trait will be consistently expressed in this species and onto offspring

4. Examples of Directional Selection:
Giraffes

5. Moths

6. Horses

7. The Result
phenotype
A shift in the average range of a species

8. Artificial Breeding
Directional Selection commonly used with Artificial Breeding
Humans are the directional breeders
Used to produce more breeds and genetic variation in plants and animals
Allows for domestication
Species has a higher chance of being selected
Proves that variety in species nowadays traces back to ancestral relatives

9. Example of Artificial Breeding
Ex. wolves vs. dogs:
Dogs are referred to as being direct descendants of wolves, and therefore considered a subspecies.

10. Pros Cons Reproductive success
Adds genetic diversity
Favored
Species seen as greater (enhanced and advanced)
Connects to beneficial mutation
Traits or alleles in species become eliminated
Loss of biodiversity
No guarantee that all crossbreeding attempts will work
Population vulnerable to disease
Limited to genetic variability
Produce heritable changes

11. Conclusion Any Questions?
If Directional Selection continues, a species won’t have genetic variation
Characteristics from the favored P-generation will carry on to the F1 Generation (their offspring) and the F2 Generation (their offspring) until the entire species has the same trait
Any Questions?