1. Define evolution.

The process of the genes changing over generations

2. Describe the “steps” of natural selection and explain how it can cause evolution in a population of organisms.

Genetic variation

Offspring who form genetic mutations as a result of their environment have adapted

‘survival of the fittest’

Mutated offspring go to have children and pass down adaptations to their offspring

Evolution relies upon the notion that mutated traits are passed on from mutated parents that have adapted to their environment and survived in a large population. This relies on the knowledge that only those with suitable characteristics survive and reproduce, promoting the frequency of an adapted trait.

3. Identify and describe the factors that cause genetic variation in a population

Mutation - in the chromosomes

Meiosis - crossing over in prophase 1, independent assortment in metaphase 1

Sexual reproduction - traits are mixed with each generation of offspring

4. Describe and explain the evolution of beak shape/size in the finches on different islands in the Galapagos.

Finches who were able to eat faster and more efficiently were able to survive when comparing the medium ground finch with a large beak and the small ground finch with a small beak. The medium ground finch were able to outcompete the small ground finch and thanks to a lack of competition the medium ground finch adapted to be smaller. After a drought in 1977, the populations of medium ground finches were dying, those with small beaks at a higher rate because there were then no smaller seeds due to the environment. The surviving population then passed down the large beak trait.

5. Describe and explain the evolution of the peppered moth population in response to environmental changes in England (ex: industrialization and pollution).

The peppered moth population originally had a high population of light-colored moths, as they were able to camouflage in their environment. During industrialization in England, the environment became covered in a noxious sulfur oxide soot, to which the melanistic variety was more efficiently able to blend into the polluted environment, displaying melanistic industrialization.

6. Explain the evolution of antibiotic resistant strains of bacteria. Describe how plasmids containing genes for antibiotic resistance can be transferred between bacteria by conjugation. Describe how misuse of antibiotics can accelerate the evolution of antibiotic-resistant bacteria.

Some bacteria will develop resistance to bacteria and multiply rapidly due to binary fission. These mutated genes are able to be exchanged by conjugation, in their plasmids. When antibiotics are taken at doses higher than recommended, there is a higher likelihood of mutations occurring and multiplying because the bacteria sense it in greater quantities.

7. Explain why evolution tends to occur more quickly in populations of organisms that have short lifespans and reproduce quickly.

More generations more quickly so traits will be passed down much faster

Populations of organisms that die quickly have faster methods of reproduction, such as binary fission in bacteria. Therefore, it is easier for the mutated genes to be exchanged when a mutation occurs, and for the frequency of the trait to become much higher than the frequency of an unmutated trait.

8. Explain and provide examples of how selective breeding of domesticated animals and crops shows that artificial selection can cause evolution

Great Danes: for centuries, humans have chosen the largest male and the largest female dog to crossbreed, which resulted in the Great Dane breed, known as the largest breed of dogs.

Crossing of certain traits in a plant (vitamin, number of leaves, pigmentation, etc.)has resulted in different varieties of plants that have a high frequency of said trait.

9. Define homologous structures, provide examples (ex: bone structure of vertebrate pentadactyl limbs), and explain how they arise by adaptive radiation (i.e., divergent evolution).

Homologous structures are similar structures that arise from a common ancestor. The characteristics will diverge when adapting to the environment, and adaptive radiation takes place when the characteristic rapidly multiplies in the population.

10. Define analogous structures, provide examples, and explain how they arise by convergent evolution.

Analogous structures are structures that arise from a not common ancestor, simply a result of evolving in similar environments. This is called convergent evolution, when two organisms develop similar characteristics due to similar environments, not a common ancestor.