Short Summary: Natural selection is the process by which heritable traits become more or less common. Gene flow, competitive exclusion, mutation, adaptation and genetic bottlenecks are key evolutionary processes leading to speciation due to reproductive barriers.

1. What is the concept of natural selection?
Answer: Natural selection is the process by which certain heritable traits become more or less common in a population due to the effects of differential reproduction and survival.

2. What is gene flow?
Answer: Gene flow is the movement of alleles among populations as a result of interbreeding or immigration.

3. What is the principle of competitive exclusion?
Answer: The competitive exclusion principle states that two species competing for the same resources cannot coexist in the same habitat.

4. What is the relevant timescale for microevolution?
Answer: The relevant timescale for microevolution is the lifetime of a species, which can be as short as about 100 years for a rapidly evolving organism or as long as many millions of years for a more slowly evolving species.

5. What are stabilizing and directional selection?
Answer: Stabilizing selection acts to reduce the degree of variation within a population by reducing the extreme phenotypes and favoring intermediate forms. Directional selection is a strong force toward a certain phenotype, usually the extreme phenotype that maximizes the chance of survival and reproduction.

6. What is diversifying selection?
Answer: Diversifying selection increases variation in a population by favoring different types of phenotypes and creating a wider range of variation.

7. What are mutations?
Answer: Mutations are changes in the DNA sequence that can cause changes in the gene product and phenotype.

8. What is local adaptation?
Answer: Local adaptation is the process in which populations become adapted to the environment of their own geographic location by the process of natural selection.

9. What is gene drift?
Answer: Gene drift is a cause of genetic variation in which the frequency of an allele in a population changes due to chance events such as genetic drift, mutation and migration.

10. What are genetic bottlenecks?
Answer: Genetic bottlenecks occur when a population experiences a drastic reduction in size and variability due to external events.

11. What is a founder effect?
Answer: A founder effect occurs when a small number of individuals establish a new population, introducing a unique set of alleles that may not be representative of the original population.

12. What is a speciation event?
Answer: A speciation event is an event in which a new species is created through the process of gene flow and selection.

13. What is genetic isolation?
Answer: Genetic isolation is a process by which two populations of a species are prevented from interbreeding due to physical or geographical factors.

14. What is the allopatric model of speciation?
Answer: The allopatric model of speciation proposes that when two populations of a species are geographically separated, they will no longer be able to interbreed, leading to the formation of two distinct species.

15. What is a reproductive barrier?
Answer: A reproductive barrier is any physical or biological feature that prevents two populations of the same species from interbreeding.