The Best Selection

1. The Best Selection Topic 6

2. Darwin’s Theory • Charles Darwin is the main contributor to the theory of natural selection. • He sailed around the world collecting specimens and data. • He noticed the vast amounts of biological diversity. He also noticed the finches. • He continued to study the finches and created a theory about how the fittest or the best-adapted organisms for a specific environment survived.

4. Natural Selection The theory, proposed by Charles Darwin, can be summed up in four statements • All organisms produce more offspring than can possibly survive. • There is incredible variation within each species. • Some of those variations increase the chances of an organism surviving to reproduce. • Over time, variations that are passed on lead to changes in the genetic characteristics of a species.

5. Selecting Desirable Traits • Artificial Selection • Process of selecting and breeding individuals with desirable traits to produce offspring that have these desired traits • Ex. Horses, dogs, livestock, corn

7. Clones • A genetically identical copy of an entire organism or of its cells or genes • Cloning is the process of creating a clone • Ex. Cutting from a plant

8. Artificial Reproductive Technology • Artificial Insemination • Sperm are harvested from a desirable male and injected into a female • Ex. Livestock breeding • In Vitro Fertilization • Fertilization that happens outside the body, usually in a petri dish (embryo is placed in female) • Ex. Livestock breeding

9. Genetic Engineering • Definition: a technique involved in moving pieces of DNA from one cell to another. • Ex. Human-producing gene for insulin is inserted into bacterial DNA. Bacteria reproduces quickly and can produce insulin quickly and cheaply. • Ex. Moving protein-making genes into the transgenic (or genetically modified) animals who will produce the human proteins necessary to aid those who are deficient in a certain protein. • Transgenic animals are created by inserting human genes into the fertilized eggs of the animal.

10. Biotechnology in Food Production • Ex. An “antifreeze” gene has been inserted into fish from areas of decreasing populations. • Ex. A cold-resistant gene from fish has been inserted into tomatoes to help them withstand cold during growth. • Ex. Crops have been inserted with genes that help them resist pests and insects. • Ex. Cotton, corn and potatoes have been engineered to produce Bt Toxin. Insects that eat the engineered plant die, no pesticides are needed.

11. Biotechnology and Society • Risks in Animals • Decreased genetic diversity • More susceptible to disease • Cattle cloning – unsuccessful pregnancies, birth defects and deaths

12. Biotechnologies in Society • Risks in Plants • Genetically engineered canola could interbreed with weeds making their offspring resistant to herbicides.

13. Review Questions • How does artificial selection differ from what you learned about natural selection? Use examples. • How have reproductive technologies benefited agricultural industries in Alberta? Provide examples. What human needs do these technologies reflect? • What are some advantages of biotechnology such as cloning? What are some disadvantages? • Scientists have created crops that contain a toxin that kills any insect that eats them. Some farmers have been growing corn plants that contain this toxin. Corn without the toxin is a food supply to corn weevil, which destroys the corn crop, and the monarch butterfly, which is a protected species. What advice would you give to farmers growing this crop?